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curl(1) curl Manual curl(1)
NAME
curl - transfer a URL
SYNOPSIS
curl [options / URLs]
DESCRIPTION
curl is a tool for transferring data from or to a server using URLs. It
supports these protocols: DICT, FILE, FTP, FTPS, GOPHER, GOPHERS, HTTP,
HTTPS, IMAP, IMAPS, LDAP, LDAPS, MQTT, POP3, POP3S, RTMP, RTMPS, RTSP,
SCP, SFTP, SMB, SMBS, SMTP, SMTPS, TELNET, TFTP, WS and WSS.
curl is powered by libcurl for all transfer-related features. See
libcurl(3) for details.
URL
The URL syntax is protocol-dependent. You find a detailed description
in RFC 3986.
If you provide a URL without a leading protocol:// scheme, curl guesses
what protocol you want. It then defaults to HTTP but assumes others
based on often-used host name prefixes. For example, for host names
starting with "ftp." curl assumes you want FTP.
You can specify any amount of URLs on the command line. They are
fetched in a sequential manner in the specified order unless you use
-Z, --parallel. You can specify command line options and URLs mixed and
in any order on the command line.
curl attempts to reuse connections when doing multiple transfers, so
that getting many files from the same server do not use multiple
connects and setup handshakes. This improves speed. Connection reuse
can only be done for URLs specified for a single command line
invocation and cannot be performed between separate curl runs.
Provide an IPv6 zone id in the URL with an escaped percentage sign.
Like in
"http://[fe80::3%25eth0]/"
Everything provided on the command line that is not a command line
option or its argument, curl assumes is a URL and treats it as such.
GLOBBING
You can specify multiple URLs or parts of URLs by writing lists within
braces or ranges within brackets. We call this "globbing".
Provide a list with three different names like this:
"http://site.{one,two,three}.com"
or you can get sequences of alphanumeric series by using [] as in:
"ftp://ftp.example.com/file[1-100].txt"
"ftp://ftp.example.com/file[001-100].txt" (with leading zeros)
You can specify a step counter for the ranges to get every Nth number
or letter:
"http://example.com/file[1-100:10].txt"
"http://example.com/file[a-z:2].txt"
When using [] or {} sequences when invoked from a command line prompt,
you probably have to put the full URL within double quotes to avoid the
shell from interfering with it. This also goes for other characters
treated special, like for example '&', '?' and '*'.
Switch off globbing with -g, --globoff.
VARIABLES
curl supports command line variables (added in 8.3.0). Set variables
with --variable name=content or --variable name@file (where "file" can
be stdin if set to a single dash (-)).
Variable contents can expanded in option parameters using "{{name}}"
(without the quotes) if the option name is prefixed with "--expand-".
This gets the contents of the variable "name" inserted, or a blank if
the name does not exist as a variable. Insert "{{" verbatim in the
string by prefixing it with a backslash, like "\{{".
You an access and expand environment variables by first importing them.
You can select to either require the environment variable to be set or
you can provide a default value in case it is not already set. Plain
--variable %name imports the variable called 'name' but exits with an
error if that environment variable is not already set. To provide a
default value if it is not set, use --variable %name=content or
--variable %name@content.
Example. Get the USER environment variable into the URL, fail if USER
is not set:
--variable '%USER'
--expand-url = "https://example.com/api/{{USER}}/method"
When expanding variables, curl supports a set of functions that can
make the variable contents more convenient to use. It can trim leading
and trailing white space with trim, it can output the contents as a
JSON quoted string with json, URL encode the string with url or base64
encode it with b64. You apply function to a variable expansion, add
them colon separated to the right side of the variable. Variable
content holding null bytes that are not encoded when expanded cause
error.
Example: get the contents of a file called $HOME/.secret into a
variable called "fix". Make sure that the content is trimmed and
percent-encoded sent as POST data:
--variable %HOME
--expand-variable fix@{{HOME}}/.secret
--expand-data "{{fix:trim:url}}"
https://example.com/
Command line variables and expansions were added in in 8.3.0.
curl does not parse or otherwise "understand" the content it gets or
writes as output. It does no encoding or decoding, unless explicitly
asked to with dedicated command line options.
PROTOCOLS
curl supports numerous protocols, or put in URL terms: schemes. Your
particular build may not support them all.
DICT Lets you lookup words using online dictionaries.
FILE Read or write local files. curl does not support accessing
file:// URL remotely, but when running on Microsoft Windows
using the native UNC approach works.
FTP(S) curl supports the File Transfer Protocol with a lot of tweaks
and levers. With or without using TLS.
GOPHER(S)
Retrieve files.
HTTP(S)
curl supports HTTP with numerous options and variations. It can
speak HTTP version 0.9, 1.0, 1.1, 2 and 3 depending on build
options and the correct command line options.
IMAP(S)
Using the mail reading protocol, curl can "download" emails for
you. With or without using TLS.
LDAP(S)
curl can do directory lookups for you, with or without TLS.
MQTT curl supports MQTT version 3. Downloading over MQTT equals
"subscribe" to a topic while uploading/posting equals "publish"
on a topic. MQTT over TLS is not supported (yet).
POP3(S)
Downloading from a pop3 server means getting a mail. With or
without using TLS.
RTMP(S)
The Realtime Messaging Protocol is primarily used to serve
streaming media and curl can download it.
RTSP curl supports RTSP 1.0 downloads.
SCP curl supports SSH version 2 scp transfers.
SFTP curl supports SFTP (draft 5) done over SSH version 2.
SMB(S) curl supports SMB version 1 for upload and download.
SMTP(S)
Uploading contents to an SMTP server means sending an email.
With or without TLS.
TELNET Telling curl to fetch a telnet URL starts an interactive session
where it sends what it reads on stdin and outputs what the
server sends it.
second. The suffixes (k, M, G, T, P) are 1024 based. For example 1k is
1024 bytes. 1M is 1048576 bytes.
curl displays this data to the terminal by default, so if you invoke
curl to do an operation and it is about to write data to the terminal,
it disables the progress meter as otherwise it would mess up the output
mixing progress meter and response data.
If you want a progress meter for HTTP POST or PUT requests, you need to
redirect the response output to a file, using shell redirect (>), -o,
--output or similar.
This does not apply to FTP upload as that operation does not spit out
any response data to the terminal.
If you prefer a progress "bar" instead of the regular meter, -#,
--progress-bar is your friend. You can also disable the progress meter
completely with the -s, --silent option.
VERSION
This man page describes curl 8.5.0. If you use a later version, chances
are this man page does not fully document it. If you use an earlier
version, this document tries to include version information about which
specific version that introduced changes.
You can always learn which the latest curl version is by running
curl https://curl.se/info
The online version of this man page is always showing the latest
incarnation: https://curl.se/docs/manpage.html
OPTIONS
Options start with one or two dashes. Many of the options require an
additional value next to them. If provided text does not start with a
dash, it is presumed to be and treated as a URL.
The short "single-dash" form of the options, -d for example, may be
used with or without a space between it and its value, although a space
is a recommended separator. The long "double-dash" form, -d, --data for
example, requires a space between it and its value.
Short version options that do not need any additional values can be
used immediately next to each other, like for example you can specify
all the options -O, -L and -v at once as -OLv.
In general, all boolean options are enabled with --option and yet again
disabled with --no-option. That is, you use the same option name but
prefix it with "no-". However, in this list we mostly only list and
show the --option version of them.
When -:, --next is used, it resets the parser state and you start again
with a clean option state, except for the options that are "global".
Global options retain their values and meaning even after -:, --next.
The following options are global: --fail-early, --libcurl,
--parallel-immediate, -Z, --parallel, -#, --progress-bar, --rate, -S,
--show-error, --stderr, --styled-output, --trace-ascii, --trace-config,
--trace-ids, --trace-time, --trace and -v, --verbose.
If --abstract-unix-socket is provided several times, the last
set value is used.
Example:
curl --abstract-unix-socket socketpath https://example.com
See also --unix-socket. Added in 7.53.0.
--alt-svc <file name>
(HTTPS) This option enables the alt-svc parser in curl. If the
file name points to an existing alt-svc cache file, that gets
used. After a completed transfer, the cache is saved to the file
name again if it has been modified.
Specify a "" file name (zero length) to avoid loading/saving and
make curl just handle the cache in memory.
If this option is used several times, curl loads contents from
all the files but the last one is used for saving.
--alt-svc can be used several times in a command line
Example:
curl --alt-svc svc.txt https://example.com
See also --resolve and --connect-to. Added in 7.64.1.
--anyauth
(HTTP) Tells curl to figure out authentication method by itself,
and use the most secure one the remote site claims to support.
This is done by first doing a request and checking the
response-headers, thus possibly inducing an extra network
round-trip. This is used instead of setting a specific
authentication method, which you can do with --basic, --digest,
--ntlm, and --negotiate.
Using --anyauth is not recommended if you do uploads from stdin,
since it may require data to be sent twice and then the client
must be able to rewind. If the need should arise when uploading
from stdin, the upload operation fails.
Used together with -u, --user.
Providing --anyauth multiple times has no extra effect.
Example:
curl --anyauth --user me:pwd https://example.com
See also --proxy-anyauth, --basic and --digest.
-a, --append
(FTP SFTP) When used in an upload, this option makes curl append
to the target file instead of overwriting it. If the remote file
does not exist, it is created. Note that this flag is ignored by
some SFTP servers (including OpenSSH).
Providing -a, --append multiple times has no extra effect.
Disable it again with --no-append.
The provider argument is a string that is used by the algorithm
when creating outgoing authentication headers.
The region argument is a string that points to a geographic area
of a resources collection (region-code) when the region name is
omitted from the endpoint.
The service argument is a string that points to a function
provided by a cloud (service-code) when the service name is
omitted from the endpoint.
If --aws-sigv4 is provided several times, the last set value is
used.
Example:
curl --aws-sigv4 "aws:amz:us-east-2:es" --user "key:secret" https://example.com
See also --basic and -u, --user. Added in 7.75.0.
--basic
(HTTP) Tells curl to use HTTP Basic authentication with the
remote host. This is the default and this option is usually
pointless, unless you use it to override a previously set option
that sets a different authentication method (such as --ntlm,
--digest, or --negotiate).
Used together with -u, --user.
Providing --basic multiple times has no extra effect.
Example:
curl -u name:password --basic https://example.com
See also --proxy-basic.
--ca-native
(TLS) Tells curl to use the CA store from the native operating
system to verify the peer. By default, curl otherwise uses a CA
store provided in a single file or directory, but when using
this option it interfaces the operating system's own vault.
This option only works for curl on Windows when built to use
OpenSSL. When curl on Windows is built to use Schannel, this
feature is implied and curl then only uses the native CA store.
curl built with wolfSSL also supports this option (added in
8.3.0).
Providing --ca-native multiple times has no extra effect.
Disable it again with --no-ca-native.
Example:
curl --ca-native https://example.com
See also --cacert, --capath and -k, --insecure. Added in 8.2.0.
--cacert <file>
(TLS) Tells curl to use the specified certificate file to verify
bundle. This option overrides that variable.
The windows version of curl automatically looks for a CA certs
file named 'curl-ca-bundle.crt', either in the same directory as
curl.exe, or in the Current Working Directory, or in any folder
along your PATH.
(iOS and macOS only) If curl is built against Secure Transport,
then this option is supported for backward compatibility with
other SSL engines, but it should not be set. If the option is
not set, then curl uses the certificates in the system and user
Keychain to verify the peer, which is the preferred method of
verifying the peer's certificate chain.
(Schannel only) This option is supported for Schannel in Windows
7 or later (added in 7.60.0). This option is supported for
backward compatibility with other SSL engines; instead it is
recommended to use Windows' store of root certificates (the
default for Schannel).
If --cacert is provided several times, the last set value is
used.
Example:
curl --cacert CA-file.txt https://example.com
See also --capath and -k, --insecure.
--capath <dir>
(TLS) Tells curl to use the specified certificate directory to
verify the peer. Multiple paths can be provided by separating
them with ":" (e.g. "path1:path2:path3"). The certificates must
be in PEM format, and if curl is built against OpenSSL, the
directory must have been processed using the c_rehash utility
supplied with OpenSSL. Using --capath can allow OpenSSL-powered
curl to make SSL-connections much more efficiently than using
--cacert if the --cacert file contains many CA certificates.
If this option is set, the default capath value is ignored.
If --capath is provided several times, the last set value is
used.
Example:
curl --capath /local/directory https://example.com
See also --cacert and -k, --insecure.
--cert-status
(TLS) Tells curl to verify the status of the server certificate
by using the Certificate Status Request (aka. OCSP stapling) TLS
extension.
If this option is enabled and the server sends an invalid (e.g.
expired) response, if the response suggests that the server
certificate has been revoked, or no response at all is received,
the verification fails.
This is currently only implemented in the OpenSSL and GnuTLS
See also --pinnedpubkey.
--cert-type <type>
(TLS) Tells curl what type the provided client certificate is
using. PEM, DER, ENG and P12 are recognized types.
The default type depends on the TLS backend and is usually PEM,
however for Secure Transport and Schannel it is P12. If -E,
--cert is a pkcs11: URI then ENG is the default type.
If --cert-type is provided several times, the last set value is
used.
Example:
curl --cert-type PEM --cert file https://example.com
See also -E, --cert, --key and --key-type.
-E, --cert <certificate[:password]>
(TLS) Tells curl to use the specified client certificate file
when getting a file with HTTPS, FTPS or another SSL-based
protocol. The certificate must be in PKCS#12 format if using
Secure Transport, or PEM format if using any other engine. If
the optional password is not specified, it is queried for on the
terminal. Note that this option assumes a certificate file that
is the private key and the client certificate concatenated. See
-E, --cert and --key to specify them independently.
In the <certificate> portion of the argument, you must escape
the character ":" as "\:" so that it is not recognized as the
password delimiter. Similarly, you must escape the character "\"
as "\\" so that it is not recognized as an escape character.
If curl is built against OpenSSL library, and the engine pkcs11
is available, then a PKCS#11 URI (RFC 7512) can be used to
specify a certificate located in a PKCS#11 device. A string
beginning with "pkcs11:" is interpreted as a PKCS#11 URI. If a
PKCS#11 URI is provided, then the --engine option is set as
"pkcs11" if none was provided and the --cert-type option is set
as "ENG" if none was provided.
(iOS and macOS only) If curl is built against Secure Transport,
then the certificate string can either be the name of a
certificate/private key in the system or user keychain, or the
path to a PKCS#12-encoded certificate and private key. If you
want to use a file from the current directory, please precede it
with "./" prefix, in order to avoid confusion with a nickname.
(Schannel only) Client certificates must be specified by a path
expression to a certificate store. (Loading PFX is not
supported; you can import it to a store first). You can use
"<store location>\<store name>\<thumbprint>" to refer to a
certificate in the system certificates store, for example,
"CurrentUser\MY\934a7ac6f8a5d579285a74fa61e19f23ddfe8d7a".
Thumbprint is usually a SHA-1 hex string which you can see in
certificate details. Following store locations are supported:
CurrentUser, LocalMachine, CurrentService, Services,
CurrentUserGroupPolicy, LocalMachineGroupPolicy and
See also --cert-type, --key and --key-type.
--ciphers <list of ciphers>
(TLS) Specifies which ciphers to use in the connection. The list
of ciphers must specify valid ciphers. Read up on SSL cipher
list details on this URL:
https://curl.se/docs/ssl-ciphers.html
If --ciphers is provided several times, the last set value is
used.
Example:
curl --ciphers ECDHE-ECDSA-AES256-CCM8 https://example.com
See also --tlsv1.3, --tls13-ciphers and --proxy-ciphers.
--compressed-ssh
(SCP SFTP) Enables built-in SSH compression. This is a request,
not an order; the server may or may not do it.
Providing --compressed-ssh multiple times has no extra effect.
Disable it again with --no-compressed-ssh.
Example:
curl --compressed-ssh sftp://example.com/
See also --compressed. Added in 7.56.0.
--compressed
(HTTP) Request a compressed response using one of the algorithms
curl supports, and automatically decompress the content.
Response headers are not modified when saved, so if they are
"interpreted" separately again at a later point they might
appear to be saying that the content is (still) compressed;
while in fact it has already been decompressed.
If this option is used and the server sends an unsupported
encoding, curl reports an error. This is a request, not an
order; the server may or may not deliver data compressed.
Providing --compressed multiple times has no extra effect.
Disable it again with --no-compressed.
Example:
curl --compressed https://example.com
See also --compressed-ssh.
-K, --config <file>
Specify a text file to read curl arguments from. The command
line arguments found in the text file are used as if they were
provided on the command line.
Options and their parameters must be specified on the same line
in the file, separated by whitespace, colon, or the equals sign.
Long option names can optionally be given in the config file
quotes ("). Within double quotes the following escape sequences
are available: \\, \", \t, \n, \r and \v. A backslash preceding
any other letter is ignored.
If the first non-blank column of a config line is a '#'
character, that line is treated as a comment.
Only write one option per physical line in the config file. A
single line is required to be no more than 10 megabytes (since
8.2.0).
Specify the filename to -K, --config as '-' to make curl read
the file from stdin.
Note that to be able to specify a URL in the config file, you
need to specify it using the --url option, and not by simply
writing the URL on its own line. So, it could look similar to
this:
url = "https://curl.se/docs/"
# --- Example file ---
# this is a comment
url = "example.com"
output = "curlhere.html"
user-agent = "superagent/1.0"
# and fetch another URL too
url = "example.com/docs/manpage.html"
-O
referer = "http://nowhereatall.example.com/"
# --- End of example file ---
When curl is invoked, it (unless -q, --disable is used) checks
for a default config file and uses it if found, even when -K,
--config is used. The default config file is checked for in the
following places in this order:
1) "$CURL_HOME/.curlrc"
2) "$XDG_CONFIG_HOME/curlrc" (Added in 7.73.0)
3) "$HOME/.curlrc"
4) Windows: "%USERPROFILE%\.curlrc"
5) Windows: "%APPDATA%\.curlrc"
6) Windows: "%USERPROFILE%\Application Data\.curlrc"
7) Non-Windows: use getpwuid to find the home directory
8) On Windows, if it finds no .curlrc file in the sequence
described above, it checks for one in the same dir the curl
executable is placed.
On Windows two filenames are checked per location: .curlrc and
_curlrc, preferring the former. Older versions on Windows
checked for _curlrc only.
--connect-timeout <fractional seconds>
Maximum time in seconds that you allow curl's connection to
take. This only limits the connection phase, so if curl
connects within the given period it continues - if not it exits.
This option accepts decimal values. The decimal value needs to
be provided using a dot (.) as decimal separator - not the local
version even if it might be using another separator.
The connection phase is considered complete when the DNS lookup
and requested TCP, TLS or QUIC handshakes are done.
If --connect-timeout is provided several times, the last set
value is used.
Examples:
curl --connect-timeout 20 https://example.com
curl --connect-timeout 3.14 https://example.com
See also -m, --max-time.
--connect-to <HOST1:PORT1:HOST2:PORT2>
For a request to the given HOST1:PORT1 pair, connect to
HOST2:PORT2 instead. This option is suitable to direct requests
at a specific server, e.g. at a specific cluster node in a
cluster of servers. This option is only used to establish the
network connection. It does NOT affect the hostname/port that is
used for TLS/SSL (e.g. SNI, certificate verification) or for the
application protocols. "HOST1" and "PORT1" may be the empty
string, meaning "any host/port". "HOST2" and "PORT2" may also be
the empty string, meaning "use the request's original
host/port".
A "host" specified to this option is compared as a string, so it
needs to match the name used in request URL. It can be either
numerical such as "127.0.0.1" or the full host name such as
"example.org".
--connect-to can be used several times in a command line
Example:
curl --connect-to example.com:443:example.net:8443 https://example.com
See also --resolve and -H, --header.
-C, --continue-at <offset>
Continue/Resume a previous file transfer at the given offset.
The given offset is the exact number of bytes that are skipped,
counting from the beginning of the source file before it is
transferred to the destination. If used with uploads, the FTP
server command SIZE is not used by curl.
Use "-C -" to tell curl to automatically find out where/how to
resume the transfer. It then uses the given output/input files
to figure that out.
If -C, --continue-at is provided several times, the last set
-c, --cookie-jar <filename>
(HTTP) Specify to which file you want curl to write all cookies
after a completed operation. Curl writes all cookies from its
in-memory cookie storage to the given file at the end of
operations. If no cookies are known, no data is written. The
file is created using the Netscape cookie file format. If you
set the file name to a single dash, "-", the cookies are written
to stdout.
The file specified with -c, --cookie-jar is only used for
output. No cookies are read from the file. To read cookies, use
the -b, --cookie option. Both options can specify the same file.
This command line option activates the cookie engine that makes
curl record and use cookies. The -b, --cookie option also
activates it.
If the cookie jar cannot be created or written to, the whole
curl operation does not fail or even report an error clearly.
Using -v, --verbose gets a warning displayed, but that is the
only visible feedback you get about this possibly lethal
situation.
If -c, --cookie-jar is provided several times, the last set
value is used.
Examples:
curl -c store-here.txt https://example.com
curl -c store-here.txt -b read-these https://example.com
See also -b, --cookie.
-b, --cookie <data|filename>
(HTTP) Pass the data to the HTTP server in the Cookie header. It
is supposedly the data previously received from the server in a
"Set-Cookie:" line. The data should be in the format
"NAME1=VALUE1; NAME2=VALUE2". This makes curl use the cookie
header with this content explicitly in all outgoing request(s).
If multiple requests are done due to authentication, followed
redirects or similar, they all get this cookie passed on.
If no '=' symbol is used in the argument, it is instead treated
as a filename to read previously stored cookie from. This option
also activates the cookie engine which makes curl record
incoming cookies, which may be handy if you are using this in
combination with the -L, --location option or do multiple URL
transfers on the same invoke. If the file name is exactly a
minus ("-"), curl instead reads the contents from stdin.
The file format of the file to read cookies from should be plain
HTTP headers (Set-Cookie style) or the Netscape/Mozilla cookie
file format.
The file specified with -b, --cookie is only used as input. No
cookies are written to the file. To store cookies, use the -c,
--cookie-jar option.
If you use the Set-Cookie file format and do not specify a
-c, --cookie-jar in the same command line is common.
-b, --cookie can be used several times in a command line
Examples:
curl -b cookiefile https://example.com
curl -b cookiefile -c cookiefile https://example.com
See also -c, --cookie-jar and -j, --junk-session-cookies.
--create-dirs
When used in conjunction with the -o, --output option, curl
creates the necessary local directory hierarchy as needed. This
option creates the directories mentioned with the -o, --output
option combined with the path possibly set with --output-dir. If
the combined output file name uses no directory, or if the
directories it mentions already exist, no directories are
created.
Created directories are made with mode 0750 on unix style file
systems.
To create remote directories when using FTP or SFTP, try
--ftp-create-dirs.
Providing --create-dirs multiple times has no extra effect.
Disable it again with --no-create-dirs.
Example:
curl --create-dirs --output local/dir/file https://example.com
See also --ftp-create-dirs and --output-dir.
--create-file-mode <mode>
(SFTP SCP FILE) When curl is used to create files remotely using
one of the supported protocols, this option allows the user to
set which 'mode' to set on the file at creation time, instead of
the default 0644.
This option takes an octal number as argument.
If --create-file-mode is provided several times, the last set
value is used.
Example:
curl --create-file-mode 0777 -T localfile sftp://example.com/new
See also --ftp-create-dirs. Added in 7.75.0.
--crlf (FTP SMTP) Convert line feeds to carriage return plus line feeds
in upload. Useful for MVS (OS/390).
(SMTP added in 7.40.0)
Providing --crlf multiple times has no extra effect. Disable it
again with --no-crlf.
Example:
curl --crlf -T file ftp://example.com/
If --crlfile is provided several times, the last set value is
used.
Example:
curl --crlfile rejects.txt https://example.com
See also --cacert and --capath.
--curves <algorithm list>
(TLS) Tells curl to request specific curves to use during SSL
session establishment according to RFC 8422, 5.1. Multiple
algorithms can be provided by separating them with ":" (e.g.
"X25519:P-521"). The parameter is available identically in the
"openssl s_client/s_server" utilities.
--curves allows a OpenSSL powered curl to make SSL-connections
with exactly the (EC) curve requested by the client, avoiding
nontransparent client/server negotiations.
If this option is set, the default curves list built into
OpenSSL are ignored.
If --curves is provided several times, the last set value is
used.
Example:
curl --curves X25519 https://example.com
See also --ciphers. Added in 7.73.0.
--data-ascii <data>
(HTTP) This is just an alias for -d, --data.
--data-ascii can be used several times in a command line
Example:
curl --data-ascii @file https://example.com
See also --data-binary, --data-raw and --data-urlencode.
--data-binary <data>
(HTTP) This posts data exactly as specified with no extra
processing whatsoever.
If you start the data with the letter @, the rest should be a
filename. Data is posted in a similar manner as -d, --data does,
except that newlines and carriage returns are preserved and
conversions are never done.
Like -d, --data the default content-type sent to the server is
application/x-www-form-urlencoded. If you want the data to be
treated as arbitrary binary data by the server then set the
content-type to octet-stream: -H "Content-Type:
application/octet-stream".
If this option is used several times, the ones following the
first append data as described in -d, --data.
--data-raw <data>
(HTTP) This posts data similarly to -d, --data but without the
special interpretation of the @ character.
--data-raw can be used several times in a command line
Examples:
curl --data-raw "hello" https://example.com
curl --data-raw "@at@at@" https://example.com
See also -d, --data.
--data-urlencode <data>
(HTTP) This posts data, similar to the other -d, --data options
with the exception that this performs URL-encoding.
To be CGI-compliant, the <data> part should begin with a name
followed by a separator and a content specification. The <data>
part can be passed to curl using one of the following syntaxes:
content
This makes curl URL-encode the content and pass that on.
Just be careful so that the content does not contain any
= or @ symbols, as that makes the syntax match one of the
other cases below!
=content
This makes curl URL-encode the content and pass that on.
The preceding = symbol is not included in the data.
name=content
This makes curl URL-encode the content part and pass that
on. Note that the name part is expected to be URL-encoded
already.
@filename
This makes curl load data from the given file (including
any newlines), URL-encode that data and pass it on in the
POST.
name@filename
This makes curl load data from the given file (including
any newlines), URL-encode that data and pass it on in the
POST. The name part gets an equal sign appended,
resulting in name=urlencoded-file-content. Note that the
name is expected to be URL-encoded already.
--data-urlencode can be used several times in a command line
Examples:
curl --data-urlencode name=val https://example.com
curl --data-urlencode =encodethis https://example.com
curl --data-urlencode name@file https://example.com
curl --data-urlencode @fileonly https://example.com
See also -d, --data and --data-raw.
-d, --data <data>
interpretation of the @ character. To post data purely binary,
you should instead use the --data-binary option. To URL-encode
the value of a form field you may use --data-urlencode.
If any of these options is used more than once on the same
command line, the data pieces specified are merged with a
separating &-symbol. Thus, using '-d name=daniel -d skill=lousy'
would generate a post chunk that looks like
'name=daniel&skill=lousy'.
If you start the data with the letter @, the rest should be a
file name to read the data from, or - if you want curl to read
the data from stdin. Posting data from a file named 'foobar'
would thus be done with -d, --data @foobar. When -d, --data is
told to read from a file like that, carriage returns and
newlines are stripped out. If you do not want the @ character to
have a special interpretation use --data-raw instead.
The data for this option is passed on to the server exactly as
provided on the command line. curl does not convert, change or
improve it. It is up to the user to provide the data in the
correct form.
-d, --data can be used several times in a command line
Examples:
curl -d "name=curl" https://example.com
curl -d "name=curl" -d "tool=cmdline" https://example.com
curl -d @filename https://example.com
See also --data-binary, --data-urlencode and --data-raw. This
option is mutually exclusive to -F, --form and -I, --head and
-T, --upload-file.
--delegation <LEVEL>
(GSS/kerberos) Set LEVEL to tell the server what it is allowed
to delegate when it comes to user credentials.
none Do not allow any delegation.
policy Delegates if and only if the OK-AS-DELEGATE flag is set
in the Kerberos service ticket, which is a matter of
realm policy.
always Unconditionally allow the server to delegate.
If --delegation is provided several times, the last set value is
used.
Example:
curl --delegation "none" https://example.com
See also -k, --insecure and --ssl.
--digest
(HTTP) Enables HTTP Digest authentication. This is an
authentication scheme that prevents the password from being sent
over the wire in clear text. Use this in combination with the
See also -u, --user, --proxy-digest and --anyauth. This option
is mutually exclusive to --basic and --ntlm and --negotiate.
--disable-eprt
(FTP) Tell curl to disable the use of the EPRT and LPRT commands
when doing active FTP transfers. Curl normally first attempts to
use EPRT before using PORT, but with this option, it uses PORT
right away. EPRT is an extension to the original FTP protocol,
and does not work on all servers, but enables more functionality
in a better way than the traditional PORT command.
--eprt can be used to explicitly enable EPRT again and --no-eprt
is an alias for --disable-eprt.
If the server is accessed using IPv6, this option has no effect
as EPRT is necessary then.
Disabling EPRT only changes the active behavior. If you want to
switch to passive mode you need to not use -P, --ftp-port or
force it with --ftp-pasv.
Providing --disable-eprt multiple times has no extra effect.
Disable it again with --no-disable-eprt.
Example:
curl --disable-eprt ftp://example.com/
See also --disable-epsv and -P, --ftp-port.
--disable-epsv
(FTP) Tell curl to disable the use of the EPSV command when
doing passive FTP transfers. Curl normally first attempts to use
EPSV before PASV, but with this option, it does not try EPSV.
--epsv can be used to explicitly enable EPSV again and --no-epsv
is an alias for --disable-epsv.
If the server is an IPv6 host, this option has no effect as EPSV
is necessary then.
Disabling EPSV only changes the passive behavior. If you want to
switch to active mode you need to use -P, --ftp-port.
Providing --disable-epsv multiple times has no extra effect.
Disable it again with --no-disable-epsv.
Example:
curl --disable-epsv ftp://example.com/
See also --disable-eprt and -P, --ftp-port.
-q, --disable
If used as the first parameter on the command line, the curlrc
config file is not read or used. See the -K, --config for
details on the default config file search path.
Prior to 7.50.0 curl supported the short option name q but not
the long option name disable.
See also -K, --config.
--disallow-username-in-url
(HTTP) This tells curl to exit if passed a URL containing a
username. This is probably most useful when the URL is being
provided at runtime or similar.
Providing --disallow-username-in-url multiple times has no extra
effect. Disable it again with --no-disallow-username-in-url.
Example:
curl --disallow-username-in-url https://example.com
See also --proto. Added in 7.61.0.
--dns-interface <interface>
(DNS) Tell curl to send outgoing DNS requests through
<interface>. This option is a counterpart to --interface (which
does not affect DNS). The supplied string must be an interface
name (not an address).
If --dns-interface is provided several times, the last set value
is used.
Example:
curl --dns-interface eth0 https://example.com
See also --dns-ipv4-addr and --dns-ipv6-addr. --dns-interface
requires that the underlying libcurl was built to support c-
ares.
--dns-ipv4-addr <address>
(DNS) Tell curl to bind to a specific IP address when making
IPv4 DNS requests, so that the DNS requests originate from this
address. The argument should be a single IPv4 address.
If --dns-ipv4-addr is provided several times, the last set value
is used.
Example:
curl --dns-ipv4-addr 10.1.2.3 https://example.com
See also --dns-interface and --dns-ipv6-addr. --dns-ipv4-addr
requires that the underlying libcurl was built to support c-
ares.
--dns-ipv6-addr <address>
(DNS) Tell curl to bind to a specific IP address when making
IPv6 DNS requests, so that the DNS requests originate from this
address. The argument should be a single IPv6 address.
If --dns-ipv6-addr is provided several times, the last set value
is used.
Example:
curl --dns-ipv6-addr 2a04:4e42::561 https://example.com
See also --dns-interface and --dns-ipv4-addr. --dns-ipv6-addr
requires that the underlying libcurl was built to support c-
If --dns-servers is provided several times, the last set value
is used.
Example:
curl --dns-servers 192.168.0.1,192.168.0.2 https://example.com
See also --dns-interface and --dns-ipv4-addr. --dns-servers
requires that the underlying libcurl was built to support c-
ares.
--doh-cert-status
Same as --cert-status but used for DoH (DNS-over-HTTPS).
Providing --doh-cert-status multiple times has no extra effect.
Disable it again with --no-doh-cert-status.
Example:
curl --doh-cert-status --doh-url https://doh.example https://example.com
See also --doh-insecure. Added in 7.76.0.
--doh-insecure
Same as -k, --insecure but used for DoH (DNS-over-HTTPS).
Providing --doh-insecure multiple times has no extra effect.
Disable it again with --no-doh-insecure.
Example:
curl --doh-insecure --doh-url https://doh.example https://example.com
See also --doh-url. Added in 7.76.0.
--doh-url <URL>
Specifies which DNS-over-HTTPS (DoH) server to use to resolve
hostnames, instead of using the default name resolver mechanism.
The URL must be HTTPS.
Some SSL options that you set for your transfer also applies to
DoH since the name lookups take place over SSL. However, the
certificate verification settings are not inherited but are
controlled separately via --doh-insecure and --doh-cert-status.
This option is unset if an empty string "" is used as the URL.
(Added in 7.85.0)
If --doh-url is provided several times, the last set value is
used.
Example:
curl --doh-url https://doh.example https://example.com
See also --doh-insecure. Added in 7.62.0.
-D, --dump-header <filename>
(HTTP FTP) Write the received protocol headers to the specified
file. If no headers are received, the use of this option creates
an empty file.
If -D, --dump-header is provided several times, the last set
value is used.
Example:
curl --dump-header store.txt https://example.com
See also -o, --output.
--egd-file <file>
(TLS) Deprecated option (added in 7.84.0). Prior to that it only
had an effect on curl if built to use old versions of OpenSSL.
Specify the path name to the Entropy Gathering Daemon socket.
The socket is used to seed the random engine for SSL
connections.
If --egd-file is provided several times, the last set value is
used.
Example:
curl --egd-file /random/here https://example.com
See also --random-file.
--engine <name>
(TLS) Select the OpenSSL crypto engine to use for cipher
operations. Use --engine list to print a list of build-time
supported engines. Note that not all (and possibly none) of the
engines may be available at runtime.
If --engine is provided several times, the last set value is
used.
Example:
curl --engine flavor https://example.com
See also --ciphers and --curves.
--etag-compare <file>
(HTTP) This option makes a conditional HTTP request for the
specific ETag read from the given file by sending a custom
If-None-Match header using the stored ETag.
For correct results, make sure that the specified file contains
only a single line with the desired ETag. An empty file is
parsed as an empty ETag.
Use the option --etag-save to first save the ETag from a
response, and then use this option to compare against the saved
ETag in a subsequent request.
If --etag-compare is provided several times, the last set value
is used.
Example:
curl --etag-compare etag.txt https://example.com
See also --etag-save and -z, --time-cond. Added in 7.68.0.
If --etag-save is provided several times, the last set value is
used.
Example:
curl --etag-save storetag.txt https://example.com
See also --etag-compare. Added in 7.68.0.
--expect100-timeout <seconds>
(HTTP) Maximum time in seconds that you allow curl to wait for a
100-continue response when curl emits an Expects: 100-continue
header in its request. By default curl waits one second. This
option accepts decimal values! When curl stops waiting, it
continues as if the response has been received.
The decimal value needs to provided using a dot (.) as decimal
separator - not the local version even if it might be using
another separator.
If --expect100-timeout is provided several times, the last set
value is used.
Example:
curl --expect100-timeout 2.5 -T file https://example.com
See also --connect-timeout.
--fail-early
Fail and exit on the first detected transfer error.
When curl is used to do multiple transfers on the command line,
it attempts to operate on each given URL, one by one. By
default, it ignores errors if there are more URLs given and the
last URL's success determines the error code curl returns. So
early failures are "hidden" by subsequent successful transfers.
Using this option, curl instead returns an error on the first
transfer that fails, independent of the amount of URLs that are
given on the command line. This way, no transfer failures go
undetected by scripts and similar.
This option does not imply -f, --fail, which causes transfers to
fail due to the server's HTTP status code. You can combine the
two options, however note -f, --fail is not global and is
therefore contained by -:, --next.
This option is global and does not need to be specified for each
use of --next.
Providing --fail-early multiple times has no extra effect.
Disable it again with --no-fail-early.
Example:
curl --fail-early https://example.com https://two.example
See also -f, --fail and --fail-with-body. Added in 7.52.0.
--fail-with-body
(HTTP) Return an error on server errors where the HTTP response
fail for the same circumstances but without saving the content.
Providing --fail-with-body multiple times has no extra effect.
Disable it again with --no-fail-with-body.
Example:
curl --fail-with-body https://example.com
See also -f, --fail and --fail-early. This option is mutually
exclusive to -f, --fail. Added in 7.76.0.
-f, --fail
(HTTP) Fail fast with no output at all on server errors. This is
useful to enable scripts and users to better deal with failed
attempts. In normal cases when an HTTP server fails to deliver a
document, it returns an HTML document stating so (which often
also describes why and more). This flag prevents curl from
outputting that and return error 22.
This method is not fail-safe and there are occasions where
non-successful response codes slip through, especially when
authentication is involved (response codes 401 and 407).
Providing -f, --fail multiple times has no extra effect.
Disable it again with --no-fail.
Example:
curl --fail https://example.com
See also --fail-with-body and --fail-early. This option is
mutually exclusive to --fail-with-body.
--false-start
(TLS) Tells curl to use false start during the TLS handshake.
False start is a mode where a TLS client starts sending
application data before verifying the server's Finished message,
thus saving a round trip when performing a full handshake.
This is currently only implemented in the Secure Transport (on
iOS 7.0 or later, or OS X 10.9 or later) backend.
Providing --false-start multiple times has no extra effect.
Disable it again with --no-false-start.
Example:
curl --false-start https://example.com
See also --tcp-fastopen.
--form-escape
(HTTP) Tells curl to pass on names of multipart form fields and
files using backslash-escaping instead of percent-encoding.
If --form-escape is provided several times, the last set value
is used.
Example:
curl --form-escape -F 'field\name=curl' -F 'file=@load"this' https://example.com
is any possibility that the string value may accidentally
trigger the '@' or '<' features of -F, --form.
--form-string can be used several times in a command line
Example:
curl --form-string "data" https://example.com
See also -F, --form.
-F, --form <name=content>
(HTTP SMTP IMAP) For HTTP protocol family, this lets curl
emulate a filled-in form in which a user has pressed the submit
button. This causes curl to POST data using the Content-Type
multipart/form-data according to RFC 2388.
For SMTP and IMAP protocols, this is the means to compose a
multipart mail message to transmit.
This enables uploading of binary files etc. To force the
'content' part to be a file, prefix the file name with an @
sign. To just get the content part from a file, prefix the file
name with the symbol <. The difference between @ and < is then
that @ makes a file get attached in the post as a file upload,
while the < makes a text field and just get the contents for
that text field from a file.
Tell curl to read content from stdin instead of a file by using
- as filename. This goes for both @ and < constructs. When stdin
is used, the contents is buffered in memory first by curl to
determine its size and allow a possible resend. Defining a
part's data from a named non-regular file (such as a named pipe
or similar) is not subject to buffering and is instead read at
transmission time; since the full size is unknown before the
transfer starts, such data is sent as chunks by HTTP and
rejected by IMAP.
Example: send an image to an HTTP server, where 'profile' is the
name of the form-field to which the file portrait.jpg is the
input:
curl -F profile=@portrait.jpg https://example.com/upload.cgi
Example: send your name and shoe size in two text fields to the
server:
curl -F name=John -F shoesize=11 https://example.com/
Example: send your essay in a text field to the server. Send it
as a plain text field, but get the contents for it from a local
file:
curl -F "story=<hugefile.txt" https://example.com/
You can also tell curl what Content-Type to use by using
'type=', in a manner similar to:
curl -F "web=@index.html;type=text/html" example.com
curl -F "file=@localfile;filename=nameinpost" example.com
If filename/path contains ',' or ';', it must be quoted by
double-quotes like:
curl -F "file=@\"local,file\";filename=\"name;in;post\"" example.com
or
curl -F 'file=@"local,file";filename="name;in;post"' example.com
Note that if a filename/path is quoted by double-quotes, any
double-quote or backslash within the filename must be escaped by
backslash.
Quoting must also be applied to non-file data if it contains
semicolons, leading/trailing spaces or leading double quotes:
curl -F 'colors="red; green; blue";type=text/x-myapp' example.com
You can add custom headers to the field by setting headers=,
like
curl -F "submit=OK;headers=\"X-submit-type: OK\"" example.com
or
curl -F "submit=OK;headers=@headerfile" example.com
The headers= keyword may appear more that once and above notes
about quoting apply. When headers are read from a file, Empty
lines and lines starting with '#' are comments and ignored; each
header can be folded by splitting between two words and starting
the continuation line with a space; embedded carriage-returns
and trailing spaces are stripped. Here is an example of a
header file contents:
# This file contain two headers.
X-header-1: this is a header
# The following header is folded.
X-header-2: this is
another header
To support sending multipart mail messages, the syntax is
extended as follows:
- name can be omitted: the equal sign is the first character of
the argument,
- if data starts with '(', this signals to start a new
multipart: it can be followed by a content type specification.
- a multipart can be terminated with a '=)' argument.
Example: the following command sends an SMTP mime email
consisting in an inline part in two alternative formats: plain
text and HTML. It attaches a text file:
curl -F '=(;type=multipart/alternative' \
-F '=plain text message' \
-F '= <body>HTML message</body>;type=text/html' \
corresponding schemes, limiting lines length to 76 characters.
Example: send multipart mail with a quoted-printable text
message and a base64 attached file:
curl -F '=text message;encoder=quoted-printable' \
-F '=@localfile;encoder=base64' ... smtp://example.com
See further examples and details in the MANUAL.
-F, --form can be used several times in a command line
Example:
curl --form "name=curl" --form "file=@loadthis" https://example.com
See also -d, --data, --form-string and --form-escape. This
option is mutually exclusive to -d, --data and -I, --head and
-T, --upload-file.
--ftp-account <data>
(FTP) When an FTP server asks for "account data" after user name
and password has been provided, this data is sent off using the
ACCT command.
If --ftp-account is provided several times, the last set value
is used.
Example:
curl --ftp-account "mr.robot" ftp://example.com/
See also -u, --user.
--ftp-alternative-to-user <command>
(FTP) If authenticating with the USER and PASS commands fails,
send this command. When connecting to Tumbleweed's Secure
Transport server over FTPS using a client certificate, using
"SITE AUTH" tells the server to retrieve the username from the
certificate.
If --ftp-alternative-to-user is provided several times, the last
set value is used.
Example:
curl --ftp-alternative-to-user "U53r" ftp://example.com
See also --ftp-account and -u, --user.
--ftp-create-dirs
(FTP SFTP) When an FTP or SFTP URL/operation uses a path that
does not currently exist on the server, the standard behavior of
curl is to fail. Using this option, curl instead attempts to
create missing directories.
Providing --ftp-create-dirs multiple times has no extra effect.
Disable it again with --no-ftp-create-dirs.
Example:
curl --ftp-create-dirs -T file ftp://example.com/remote/path/file
multicwd
curl does a single CWD operation for each path part in
the given URL. For deep hierarchies this means many
commands. This is how RFC 1738 says it should be done.
This is the default but the slowest behavior.
nocwd curl does no CWD at all. curl does SIZE, RETR, STOR etc
and give a full path to the server for all these
commands. This is the fastest behavior.
singlecwd
curl does one CWD with the full target directory and then
operates on the file "normally" (like in the multicwd
case). This is somewhat more standards compliant than
'nocwd' but without the full penalty of 'multicwd'.
If --ftp-method is provided several times, the last set value is
used.
Examples:
curl --ftp-method multicwd ftp://example.com/dir1/dir2/file
curl --ftp-method nocwd ftp://example.com/dir1/dir2/file
curl --ftp-method singlecwd ftp://example.com/dir1/dir2/file
See also -l, --list-only.
--ftp-pasv
(FTP) Use passive mode for the data connection. Passive is the
internal default behavior, but using this option can be used to
override a previous -P, --ftp-port option.
Reversing an enforced passive really is not doable but you must
then instead enforce the correct -P, --ftp-port again.
Passive mode means that curl tries the EPSV command first and
then PASV, unless --disable-epsv is used.
Providing --ftp-pasv multiple times has no extra effect.
Disable it again with --no-ftp-pasv.
Example:
curl --ftp-pasv ftp://example.com/
See also --disable-epsv.
-P, --ftp-port <address>
(FTP) Reverses the default initiator/listener roles when
connecting with FTP. This option makes curl use active mode.
curl then tells the server to connect back to the client's
specified address and port, while passive mode asks the server
to setup an IP address and port for it to connect to. <address>
should be one of:
interface
e.g. "eth0" to specify which interface's IP address you
want to use (Unix only)
IP address
Disable the use of PORT with --ftp-pasv. Disable the attempt to
use the EPRT command instead of PORT by using --disable-eprt.
EPRT is really PORT++.
You can also append ":[start]-[end]" to the right of the
address, to tell curl what TCP port range to use. That means you
specify a port range, from a lower to a higher number. A single
number works as well, but do note that it increases the risk of
failure since the port may not be available.
If -P, --ftp-port is provided several times, the last set value
is used.
Examples:
curl -P - ftp:/example.com
curl -P eth0 ftp:/example.com
curl -P 192.168.0.2 ftp:/example.com
See also --ftp-pasv and --disable-eprt.
--ftp-pret
(FTP) Tell curl to send a PRET command before PASV (and EPSV).
Certain FTP servers, mainly drftpd, require this non-standard
command for directory listings as well as up and downloads in
PASV mode.
Providing --ftp-pret multiple times has no extra effect.
Disable it again with --no-ftp-pret.
Example:
curl --ftp-pret ftp://example.com/
See also -P, --ftp-port and --ftp-pasv.
--ftp-skip-pasv-ip
(FTP) Tell curl to not use the IP address the server suggests in
its response to curl's PASV command when curl connects the data
connection. Instead curl reuses the same IP address it already
uses for the control connection.
This option is enabled by default (added in 7.74.0).
This option has no effect if PORT, EPRT or EPSV is used instead
of PASV.
Providing --ftp-skip-pasv-ip multiple times has no extra effect.
Disable it again with --no-ftp-skip-pasv-ip.
Example:
curl --ftp-skip-pasv-ip ftp://example.com/
See also --ftp-pasv.
--ftp-ssl-ccc-mode <active/passive>
(FTP) Sets the CCC mode. The passive mode does not initiate the
shutdown, but instead waits for the server to do it, and does
curl --ftp-ssl-ccc-mode active --ftp-ssl-ccc ftps://example.com/
See also --ftp-ssl-ccc.
--ftp-ssl-ccc
(FTP) Use CCC (Clear Command Channel) Shuts down the SSL/TLS
layer after authenticating. The rest of the control channel
communication is be unencrypted. This allows NAT routers to
follow the FTP transaction. The default mode is passive.
Providing --ftp-ssl-ccc multiple times has no extra effect.
Disable it again with --no-ftp-ssl-ccc.
Example:
curl --ftp-ssl-ccc ftps://example.com/
See also --ssl and --ftp-ssl-ccc-mode.
--ftp-ssl-control
(FTP) Require SSL/TLS for the FTP login, clear for transfer.
Allows secure authentication, but non-encrypted data transfers
for efficiency. Fails the transfer if the server does not
support SSL/TLS.
Providing --ftp-ssl-control multiple times has no extra effect.
Disable it again with --no-ftp-ssl-control.
Example:
curl --ftp-ssl-control ftp://example.com
See also --ssl.
-G, --get
When used, this option makes all data specified with -d, --data,
--data-binary or --data-urlencode to be used in an HTTP GET
request instead of the POST request that otherwise would be
used. The data is appended to the URL with a '?' separator.
If used in combination with -I, --head, the POST data is instead
appended to the URL with a HEAD request.
Providing -G, --get multiple times has no extra effect. Disable
it again with --no-get.
Examples:
curl --get https://example.com
curl --get -d "tool=curl" -d "age=old" https://example.com
curl --get -I -d "tool=curl" https://example.com
See also -d, --data and -X, --request.
-g, --globoff
This option switches off the "URL globbing parser". When you set
this option, you can specify URLs that contain the letters {}[]
without having curl itself interpret them. Note that these
letters are not normal legal URL contents but they should be
encoded according to the URI standard.
Providing -g, --globoff multiple times has no extra effect.
--happy-eyeballs-timeout-ms <milliseconds>
Happy Eyeballs is an algorithm that attempts to connect to both
IPv4 and IPv6 addresses for dual-stack hosts, giving IPv6 a
head-start of the specified number of milliseconds. If the IPv6
address cannot be connected to within that time, then a
connection attempt is made to the IPv4 address in parallel. The
first connection to be established is the one that is used.
The range of suggested useful values is limited. Happy Eyeballs
RFC 6555 says "It is RECOMMENDED that connection attempts be
paced 150-250 ms apart to balance human factors against network
load." libcurl currently defaults to 200 ms. Firefox and Chrome
currently default to 300 ms.
If --happy-eyeballs-timeout-ms is provided several times, the
last set value is used.
Example:
curl --happy-eyeballs-timeout-ms 500 https://example.com
See also -m, --max-time and --connect-timeout. Added in 7.59.0.
--haproxy-clientip
(HTTP) Sets a client IP in HAProxy PROXY protocol v1 header at
the beginning of the connection.
For valid requests, IPv4 addresses must be indicated as a series
of exactly 4 integers in the range [0..255] inclusive written in
decimal representation separated by exactly one dot between each
other. Heading zeroes are not permitted in front of numbers in
order to avoid any possible confusion with octal numbers. IPv6
addresses must be indicated as series of 4 hexadecimal digits
(upper or lower case) delimited by colons between each other,
with the acceptance of one double colon sequence to replace the
largest acceptable range of consecutive zeroes. The total number
of decoded bits must exactly be 128.
Otherwise, any string can be accepted for the client IP and get
sent.
It replaces --haproxy-protocol if used, it is not necessary to
specify both flags.
This option is primarily useful when sending test requests to
verify a service is working as intended.
If --haproxy-clientip is provided several times, the last set
value is used.
Example:
curl --haproxy-clientip $IP
See also -x, --proxy. Added in 8.2.0.
--haproxy-protocol
(HTTP) Send a HAProxy PROXY protocol v1 header at the beginning
of the connection. This is used by some load balancers and
reverse proxies to indicate the client's true IP address and
port.
Example:
curl --haproxy-protocol https://example.com
See also -x, --proxy. Added in 7.60.0.
-I, --head
(HTTP FTP FILE) Fetch the headers only! HTTP-servers feature the
command HEAD which this uses to get nothing but the header of a
document. When used on an FTP or FILE file, curl displays the
file size and last modification time only.
Providing -I, --head multiple times has no extra effect.
Disable it again with --no-head.
Example:
curl -I https://example.com
See also -G, --get, -v, --verbose and --trace-ascii.
-H, --header <header/@file>
(HTTP IMAP SMTP) Extra header to include in information sent.
When used within an HTTP request, it is added to the regular
request headers.
For an IMAP or SMTP MIME uploaded mail built with -F, --form
options, it is prepended to the resulting MIME document,
effectively including it at the mail global level. It does not
affect raw uploaded mails (Added in 7.56.0).
You may specify any number of extra headers. Note that if you
should add a custom header that has the same name as one of the
internal ones curl would use, your externally set header is used
instead of the internal one. This allows you to make even
trickier stuff than curl would normally do. You should not
replace internally set headers without knowing perfectly well
what you are doing. Remove an internal header by giving a
replacement without content on the right side of the colon, as
in: -H "Host:". If you send the custom header with no-value then
its header must be terminated with a semicolon, such as -H
"X-Custom-Header;" to send "X-Custom-Header:".
curl makes sure that each header you add/replace is sent with
the proper end-of-line marker, you should thus not add that as a
part of the header content: do not add newlines or carriage
returns, they only mess things up for you. curl passes on the
verbatim string you give it without any filter or other safe
guards. That includes white space and control characters.
This option can take an argument in @filename style, which then
adds a header for each line in the input file. Using @- makes
curl read the header file from stdin. Added in 7.55.0.
Please note that most anti-spam utilities check the presence and
value of several MIME mail headers: these are "From:", "To:",
"Date:" and "Subject:" among others and should be added with
this option.
You need --proxy-header to send custom headers intended for an
HTTP proxy. Added in 7.37.0.
with -L, --location. This can lead to the header being sent to
other hosts than the original host, so sensitive headers should
be used with caution combined with following redirects.
-H, --header can be used several times in a command line
Examples:
curl -H "X-First-Name: Joe" https://example.com
curl -H "User-Agent: yes-please/2000" https://example.com
curl -H "Host:" https://example.com
curl -H @headers.txt https://example.com
See also -A, --user-agent and -e, --referer.
-h, --help <category>
Usage help. This lists all curl command line options within the
given category.
If no argument is provided, curl displays only the most
important command line arguments.
For category all, curl displays help for all options.
If category is specified, curl displays all available help
categories.
Example:
curl --help all
See also -v, --verbose.
--hostpubmd5 <md5>
(SFTP SCP) Pass a string containing 32 hexadecimal digits. The
string should be the 128 bit MD5 checksum of the remote host's
public key, curl refuses the connection with the host unless the
md5sums match.
If --hostpubmd5 is provided several times, the last set value is
used.
Example:
curl --hostpubmd5 e5c1c49020640a5ab0f2034854c321a8 sftp://example.com/
See also --hostpubsha256.
--hostpubsha256 <sha256>
(SFTP SCP) Pass a string containing a Base64-encoded SHA256 hash
of the remote host's public key. Curl refuses the connection
with the host unless the hashes match.
This feature requires libcurl to be built with libssh2 and does
not work with other SSH backends.
If --hostpubsha256 is provided several times, the last set value
is used.
Example:
curl --hostpubsha256 NDVkMTQxMGQ1ODdmMjQ3MjczYjAyOTY5MmRkMjVmNDQ= sftp://example.com/
If curl is told to use HTTP:// for a transfer involving a host
name that exists in the HSTS cache, it upgrades the transfer to
use HTTPS. Each HSTS cache entry has an individual life time
after which the upgrade is no longer performed.
Specify a "" file name (zero length) to avoid loading/saving and
make curl just handle HSTS in memory.
If this option is used several times, curl loads contents from
all the files but the last one is used for saving.
--hsts can be used several times in a command line
Example:
curl --hsts cache.txt https://example.com
See also --proto. Added in 7.74.0.
--http0.9
(HTTP) Tells curl to be fine with HTTP version 0.9 response.
HTTP/0.9 is a response without headers and therefore you can
also connect with this to non-HTTP servers and still get a
response since curl simply transparently downgrades - if
allowed.
HTTP/0.9 is disabled by default (added in 7.66.0)
Providing --http0.9 multiple times has no extra effect. Disable
it again with --no-http0.9.
Example:
curl --http0.9 https://example.com
See also --http1.1, --http2 and --http3. Added in 7.64.0.
-0, --http1.0
(HTTP) Tells curl to use HTTP version 1.0 instead of using its
internally preferred HTTP version.
Providing -0, --http1.0 multiple times has no extra effect.
Example:
curl --http1.0 https://example.com
See also --http0.9 and --http1.1. This option is mutually
exclusive to --http1.1 and --http2 and --http2-prior-knowledge
and --http3.
--http1.1
(HTTP) Tells curl to use HTTP version 1.1.
Providing --http1.1 multiple times has no extra effect.
Example:
curl --http1.1 https://example.com
See also -0, --http1.0 and --http0.9. This option is mutually
still do HTTP/2 the standard way with negotiated protocol
version in the TLS handshake.
Providing --http2-prior-knowledge multiple times has no extra
effect. Disable it again with --no-http2-prior-knowledge.
Example:
curl --http2-prior-knowledge https://example.com
See also --http2 and --http3. --http2-prior-knowledge requires
that the underlying libcurl was built to support HTTP/2. This
option is mutually exclusive to --http1.1 and -0, --http1.0 and
--http2 and --http3.
--http2
(HTTP) Tells curl to use HTTP version 2.
For HTTPS, this means curl negotiates HTTP/2 in the TLS
handshake. curl does this by default.
For HTTP, this means curl attempts to upgrade the request to
HTTP/2 using the Upgrade: request header.
When curl uses HTTP/2 over HTTPS, it does not itself insist on
TLS 1.2 or higher even though that is required by the
specification. A user can add this version requirement with
--tlsv1.2.
Providing --http2 multiple times has no extra effect.
Example:
curl --http2 https://example.com
See also --http1.1, --http3 and --no-alpn. --http2 requires that
the underlying libcurl was built to support HTTP/2. This option
is mutually exclusive to --http1.1 and -0, --http1.0 and
--http2-prior-knowledge and --http3.
--http3-only
(HTTP) **WARNING**: this option is experimental. Do not use in
production.
Instructs curl to use HTTP/3 to the host in the URL, with no
fallback to earlier HTTP versions. HTTP/3 can only be used for
HTTPS and not for HTTP URLs. For HTTP, this option triggers an
error.
This option allows a user to avoid using the Alt-Svc method of
upgrading to HTTP/3 when you know that the target speaks HTTP/3
on the given host and port.
This option makes curl fail if a QUIC connection cannot be
established, it does not attempt any other HTTP versions on its
own. Use --http3 for similar functionality with a fallback.
Providing --http3-only multiple times has no extra effect.
Example:
curl --http3-only https://example.com
--http3
(HTTP) **WARNING**: this option is experimental. Do not use in
production.
Tells curl to try HTTP/3 to the host in the URL, but fallback to
earlier HTTP versions if the HTTP/3 connection establishment
fails. HTTP/3 is only available for HTTPS and not for HTTP URLs.
This option allows a user to avoid using the Alt-Svc method of
upgrading to HTTP/3 when you know that the target speaks HTTP/3
on the given host and port.
When asked to use HTTP/3, curl issues a separate attempt to use
older HTTP versions with a slight delay, so if the HTTP/3
transfer fails or is slow, curl still tries to proceed with an
older HTTP version.
Use --http3-only for similar functionality without a fallback.
Providing --http3 multiple times has no extra effect.
Example:
curl --http3 https://example.com
See also --http1.1 and --http2. --http3 requires that the
underlying libcurl was built to support HTTP/3. This option is
mutually exclusive to --http1.1 and -0, --http1.0 and --http2
and --http2-prior-knowledge and --http3-only. Added in 7.66.0.
--ignore-content-length
(FTP HTTP) For HTTP, Ignore the Content-Length header. This is
particularly useful for servers running Apache 1.x, which
reports incorrect Content-Length for files larger than 2
gigabytes.
For FTP, this makes curl skip the SIZE command to figure out the
size before downloading a file.
This option does not work for HTTP if libcurl was built to use
hyper.
Providing --ignore-content-length multiple times has no extra
effect. Disable it again with --no-ignore-content-length.
Example:
curl --ignore-content-length https://example.com
See also --ftp-skip-pasv-ip.
-i, --include
Include the HTTP response headers in the output. The HTTP
response headers can include things like server name, cookies,
date of the document, HTTP version and more...
To view the request headers, consider the -v, --verbose option.
Prior to 7.75.0 curl did not print the headers if -f, --fail was
used in combination with this option and there was error
reported by server.
See also -v, --verbose.
-k, --insecure
(TLS SFTP SCP) By default, every secure connection curl makes is
verified to be secure before the transfer takes place. This
option makes curl skip the verification step and proceed without
checking.
When this option is not used for protocols using TLS, curl
verifies the server's TLS certificate before it continues: that
the certificate contains the right name which matches the host
name used in the URL and that the certificate has been signed by
a CA certificate present in the cert store. See this online
resource for further details:
https://curl.se/docs/sslcerts.html
For SFTP and SCP, this option makes curl skip the known_hosts
verification. known_hosts is a file normally stored in the
user's home directory in the ".ssh" subdirectory, which contains
host names and their public keys.
WARNING: using this option makes the transfer insecure.
When curl uses secure protocols it trusts responses and allows
for example HSTS and Alt-Svc information to be stored and used
subsequently. Using -k, --insecure can make curl trust and use
such information from malicious servers.
Providing -k, --insecure multiple times has no extra effect.
Disable it again with --no-insecure.
Example:
curl --insecure https://example.com
See also --proxy-insecure, --cacert and --capath.
--interface <name>
Perform an operation using a specified interface. You can enter
interface name, IP address or host name. An example could look
like:
curl --interface eth0:1 https://www.example.com/
On Linux it can be used to specify a VRF, but the binary needs
to either have CAP_NET_RAW or to be run as root. More
information about Linux VRF:
https://www.kernel.org/doc/Documentation/networking/vrf.txt
If --interface is provided several times, the last set value is
used.
Example:
curl --interface eth0 https://example.com
See also --dns-interface.
--ipfs-gateway <URL>
Specify which gateway to use for IPFS and IPNS URLs. Not
specifying this will instead make curl check if the IPFS_GATEWAY
curl --ipfs-gateway http://localhost:8080 ipfs://bafybeigagd5nmnn2iys2f3doro7ydrevyr2mzarwidgadawmamiteydbzi
There are many public IPFS gateways. See for example:
https://ipfs.github.io/public-gateway-checker/
WARNING: If you opt to go for a remote gateway you should be
aware that you completely trust the gateway. This is fine in
local gateways as you host it yourself. With remote gateways
there could potentially be a malicious actor returning you data
that does not match the request you made, inspect or even
interfere with the request. You will not notice this when using
curl. A mitigation could be to go for a "trustless" gateway.
This means you locally verify that the data. Consult the docs
page on trusted vs trustless:
https://docs.ipfs.tech/reference/http/gateway/#trusted-vs-trustless
If --ipfs-gateway is provided several times, the last set value
is used.
Example:
curl --ipfs-gateway https://example.com ipfs://
See also -h, --help and -M, --manual. Added in 8.4.0.
-4, --ipv4
This option tells curl to use IPv4 addresses only when resolving
host names, and not for example try IPv6.
Providing -4, --ipv4 multiple times has no extra effect.
Example:
curl --ipv4 https://example.com
See also --http1.1 and --http2. This option is mutually
exclusive to -6, --ipv6.
-6, --ipv6
This option tells curl to use IPv6 addresses only when resolving
host names, and not for example try IPv4.
Providing -6, --ipv6 multiple times has no extra effect.
Example:
curl --ipv6 https://example.com
See also --http1.1 and --http2. This option is mutually
exclusive to -4, --ipv4.
--json <data>
(HTTP) Sends the specified JSON data in a POST request to the
HTTP server. --json works as a shortcut for passing on these
three options:
--data [arg]
--header "Content-Type: application/json"
--header "Accept: application/json"
There is no verification that the passed in data is actual JSON
If this option is used more than once on the same command line,
the additional data pieces are concatenated to the previous
before sending.
The headers this option sets can be overridden with -H, --header
as usual.
--json can be used several times in a command line
Examples:
curl --json '{ "drink": "coffe" }' https://example.com
curl --json '{ "drink":' --json ' "coffe" }' https://example.com
curl --json @prepared https://example.com
curl --json @- https://example.com < json.txt
See also --data-binary and --data-raw. This option is mutually
exclusive to -F, --form and -I, --head and -T, --upload-file.
Added in 7.82.0.
-j, --junk-session-cookies
(HTTP) When curl is told to read cookies from a given file, this
option makes it discard all "session cookies". This has the same
effect as if a new session is started. Typical browsers discard
session cookies when they are closed down.
Providing -j, --junk-session-cookies multiple times has no extra
effect. Disable it again with --no-junk-session-cookies.
Example:
curl --junk-session-cookies -b cookies.txt https://example.com
See also -b, --cookie and -c, --cookie-jar.
--keepalive-time <seconds>
This option sets the time a connection needs to remain idle
before sending keepalive probes and the time between individual
keepalive probes. It is currently effective on operating systems
offering the TCP_KEEPIDLE and TCP_KEEPINTVL socket options
(meaning Linux, recent AIX, HP-UX and more). Keepalives are
used by the TCP stack to detect broken networks on idle
connections. The number of missed keepalive probes before
declaring the connection down is OS dependent and is commonly 9
or 10. This option has no effect if --no-keepalive is used.
If unspecified, the option defaults to 60 seconds.
If --keepalive-time is provided several times, the last set
value is used.
Example:
curl --keepalive-time 20 https://example.com
See also --no-keepalive and -m, --max-time.
--key-type <type>
(TLS) Private key file type. Specify which type your --key
provided private key is. DER, PEM, and ENG are supported. If not
specified, PEM is assumed.
See also --key.
--key <key>
(TLS SSH) Private key file name. Allows you to provide your
private key in this separate file. For SSH, if not specified,
curl tries the following candidates in order: '~/.ssh/id_rsa',
'~/.ssh/id_dsa', './id_rsa', './id_dsa'.
If curl is built against OpenSSL library, and the engine pkcs11
is available, then a PKCS#11 URI (RFC 7512) can be used to
specify a private key located in a PKCS#11 device. A string
beginning with "pkcs11:" is interpreted as a PKCS#11 URI. If a
PKCS#11 URI is provided, then the --engine option is set as
"pkcs11" if none was provided and the --key-type option is set
as "ENG" if none was provided.
If curl is built against Secure Transport or Schannel then this
option is ignored for TLS protocols (HTTPS, etc). Those backends
expect the private key to be already present in the keychain or
PKCS#12 file containing the certificate.
If --key is provided several times, the last set value is used.
Example:
curl --cert certificate --key here https://example.com
See also --key-type and -E, --cert.
--krb <level>
(FTP) Enable Kerberos authentication and use. The level must be
entered and should be one of 'clear', 'safe', 'confidential', or
'private'. Should you use a level that is not one of these,
'private' is used.
If --krb is provided several times, the last set value is used.
Example:
curl --krb clear ftp://example.com/
See also --delegation and --ssl. --krb requires that the
underlying libcurl was built to support Kerberos.
--libcurl <file>
Append this option to any ordinary curl command line, and you
get libcurl-using C source code written to the file that does
the equivalent of what your command-line operation does!
This option is global and does not need to be specified for each
use of --next.
If --libcurl is provided several times, the last set value is
used.
Example:
curl --libcurl client.c https://example.com
See also -v, --verbose.
--limit-rate <speed>
'm' or 'M' makes it megabytes, while 'g' or 'G' makes it
gigabytes. The suffixes (k, M, G, T, P) are 1024 based. For
example 1k is 1024. Examples: 200K, 3m and 1G.
The rate limiting logic works on averaging the transfer speed to
no more than the set threshold over a period of multiple
seconds.
If you also use the -Y, --speed-limit option, that option takes
precedence and might cripple the rate-limiting slightly, to help
keeping the speed-limit logic working.
If --limit-rate is provided several times, the last set value is
used.
Examples:
curl --limit-rate 100K https://example.com
curl --limit-rate 1000 https://example.com
curl --limit-rate 10M https://example.com
See also --rate, -Y, --speed-limit and -y, --speed-time.
-l, --list-only
(FTP POP3 SFTP) (FTP) When listing an FTP directory, this switch
forces a name-only view. This is especially useful if the user
wants to machine-parse the contents of an FTP directory since
the normal directory view does not use a standard look or
format. When used like this, the option causes an NLST command
to be sent to the server instead of LIST.
Note: Some FTP servers list only files in their response to
NLST; they do not include sub-directories and symbolic links.
(SFTP) When listing an SFTP directory, this switch forces a
name-only view, one per line. This is especially useful if the
user wants to machine-parse the contents of an SFTP directory
since the normal directory view provides more information than
just file names.
(POP3) When retrieving a specific email from POP3, this switch
forces a LIST command to be performed instead of RETR. This is
particularly useful if the user wants to see if a specific
message-id exists on the server and what size it is.
Note: When combined with -X, --request, this option can be used
to send a UIDL command instead, so the user may use the email's
unique identifier rather than its message-id to make the
request.
Providing -l, --list-only multiple times has no extra effect.
Disable it again with --no-list-only.
Example:
curl --list-only ftp://example.com/dir/
See also -Q, --quote and -X, --request.
--local-port <num/range>
Set a preferred single number or range (FROM-TO) of local port
Example:
curl --local-port 1000-3000 https://example.com
See also -g, --globoff.
--location-trusted
(HTTP) Like -L, --location, but allows sending the name +
password to all hosts that the site may redirect to. This may or
may not introduce a security breach if the site redirects you to
a site to which you send your authentication info (which is
plaintext in the case of HTTP Basic authentication).
Providing --location-trusted multiple times has no extra effect.
Disable it again with --no-location-trusted.
Example:
curl --location-trusted -u user:password https://example.com
See also -u, --user.
-L, --location
(HTTP) If the server reports that the requested page has moved
to a different location (indicated with a Location: header and a
3XX response code), this option makes curl redo the request on
the new place. If used together with -i, --include or -I,
--head, headers from all requested pages are shown.
When authentication is used, curl only sends its credentials to
the initial host. If a redirect takes curl to a different host,
it does not get the user+password pass on. See also
--location-trusted on how to change this.
Limit the amount of redirects to follow by using the
--max-redirs option.
When curl follows a redirect and if the request is a POST, it
sends the following request with a GET if the HTTP response was
301, 302, or 303. If the response code was any other 3xx code,
curl resends the following request using the same unmodified
method.
You can tell curl to not change POST requests to GET after a 30x
response by using the dedicated options for that: --post301,
--post302 and --post303.
The method set with -X, --request overrides the method curl
would otherwise select to use.
Providing -L, --location multiple times has no extra effect.
Disable it again with --no-location.
Example:
curl -L https://example.com
See also --resolve and --alt-svc.
--login-options <options>
(IMAP LDAP POP3 SMTP) Specify the login options to use during
server authentication.
Since 8.2.0, IMAP supports the login option "AUTH=+LOGIN". With
this option, curl uses the plain (not SASL) LOGIN IMAP command
even if the server advertises SASL authentication. Care should
be taken in using this option, as it sends your password over
the network in plain text. This does not work if the IMAP server
disables the plain LOGIN (e.g. to prevent password snooping).
If --login-options is provided several times, the last set value
is used.
Example:
curl --login-options 'AUTH=*' imap://example.com
See also -u, --user.
--mail-auth <address>
(SMTP) Specify a single address. This is used to specify the
authentication address (identity) of a submitted message that is
being relayed to another server.
If --mail-auth is provided several times, the last set value is
used.
Example:
curl --mail-auth user@example.come -T mail smtp://example.com/
See also --mail-rcpt and --mail-from.
--mail-from <address>
(SMTP) Specify a single address that the given mail should get
sent from.
If --mail-from is provided several times, the last set value is
used.
Example:
curl --mail-from user@example.com -T mail smtp://example.com/
See also --mail-rcpt and --mail-auth.
--mail-rcpt-allowfails
(SMTP) When sending data to multiple recipients, by default curl
aborts SMTP conversation if at least one of the recipients
causes RCPT TO command to return an error.
The default behavior can be changed by passing
--mail-rcpt-allowfails command-line option which makes curl
ignore errors and proceed with the remaining valid recipients.
If all recipients trigger RCPT TO failures and this flag is
specified, curl still aborts the SMTP conversation and returns
the error received from to the last RCPT TO command.
Providing --mail-rcpt-allowfails multiple times has no extra
effect. Disable it again with --no-mail-rcpt-allowfails.
Example:
curl --mail-rcpt-allowfails --mail-rcpt dest@example.com smtp://example.com
When performing an address verification (VRFY command), the
recipient should be specified as the user name or user name and
domain (as per Section 3.5 of RFC 5321).
When performing a mailing list expand (EXPN command), the
recipient should be specified using the mailing list name, such
as "Friends" or "London-Office".
--mail-rcpt can be used several times in a command line
Example:
curl --mail-rcpt user@example.net smtp://example.com
See also --mail-rcpt-allowfails.
-M, --manual
Manual. Display the huge help text.
Example:
curl --manual
See also -v, --verbose, --libcurl and --trace.
--max-filesize <bytes>
(FTP HTTP MQTT) Specify the maximum size (in bytes) of a file to
download. If the file requested is larger than this value, the
transfer does not start and curl returns with exit code 63.
A size modifier may be used. For example, Appending 'k' or 'K'
counts the number as kilobytes, 'm' or 'M' makes it megabytes,
while 'g' or 'G' makes it gigabytes. Examples: 200K, 3m and 1G.
(Added in 7.58.0)
NOTE: before curl 8.4.0, when the file size is not known prior
to download, for such files this option has no effect even if
the file transfer ends up being larger than this given limit.
Starting with curl 8.4.0, this option aborts the transfer if it
reaches the threshold during transfer.
If --max-filesize is provided several times, the last set value
is used.
Example:
curl --max-filesize 100K https://example.com
See also --limit-rate.
--max-redirs <num>
(HTTP) Set maximum number of redirections to follow. When -L,
--location is used, to prevent curl from following too many
redirects, by default, the limit is set to 50 redirects. Set
this option to -1 to make it unlimited.
If --max-redirs is provided several times, the last set value is
used.
Example:
hours due to slow networks or links going down. This option
accepts decimal values.
If you enable retrying the transfer (--retry) then the maximum
time counter is reset each time the transfer is retried. You can
use --retry-max-time to limit the retry time.
The decimal value needs to provided using a dot (.) as decimal
separator - not the local version even if it might be using
another separator.
If -m, --max-time is provided several times, the last set value
is used.
Examples:
curl --max-time 10 https://example.com
curl --max-time 2.92 https://example.com
See also --connect-timeout and --retry-max-time.
--metalink
This option was previously used to specify a Metalink resource.
Metalink support is disabled in curl for security reasons (added
in 7.78.0).
If --metalink is provided several times, the last set value is
used.
Example:
curl --metalink file https://example.com
See also -Z, --parallel.
--negotiate
(HTTP) Enables Negotiate (SPNEGO) authentication.
This option requires a library built with GSS-API or SSPI
support. Use -V, --version to see if your curl supports
GSS-API/SSPI or SPNEGO.
When using this option, you must also provide a fake -u, --user
option to activate the authentication code properly. Sending a
'-u :' is enough as the user name and password from the -u,
--user option are not actually used.
Providing --negotiate multiple times has no extra effect.
Example:
curl --negotiate -u : https://example.com
See also --basic, --ntlm, --anyauth and --proxy-negotiate.
--netrc-file <filename>
This option is similar to -n, --netrc, except that you provide
the path (absolute or relative) to the netrc file that curl
should use. You can only specify one netrc file per invocation.
It abides by --netrc-optional if specified.
is mutually exclusive to -n, --netrc.
--netrc-optional
Similar to -n, --netrc, but this option makes the .netrc usage
optional and not mandatory as the -n, --netrc option does.
Providing --netrc-optional multiple times has no extra effect.
Disable it again with --no-netrc-optional.
Example:
curl --netrc-optional https://example.com
See also --netrc-file. This option is mutually exclusive to -n,
--netrc.
-n, --netrc
Makes curl scan the .netrc file in the user's home directory for
login name and password. This is typically used for FTP on Unix.
If used with HTTP, curl enables user authentication. See
netrc(5) and ftp(1) for details on the file format. Curl does
not complain if that file does not have the right permissions
(it should be neither world- nor group-readable). The
environment variable "HOME" is used to find the home directory.
On Windows two filenames in the home directory are checked:
.netrc and _netrc, preferring the former. Older versions on
Windows checked for _netrc only.
A quick and simple example of how to setup a .netrc to allow
curl to FTP to the machine host.domain.com with user name
'myself' and password 'secret' could look similar to:
machine host.domain.com
login myself
password secret
Providing -n, --netrc multiple times has no extra effect.
Disable it again with --no-netrc.
Example:
curl --netrc https://example.com
See also --netrc-file, -K, --config and -u, --user. This option
is mutually exclusive to --netrc-file and --netrc-optional.
-:, --next
Tells curl to use a separate operation for the following URL and
associated options. This allows you to send several URL
requests, each with their own specific options, for example,
such as different user names or custom requests for each.
-:, --next resets all local options and only global ones have
their values survive over to the operation following the -:,
--next instruction. Global options include -v, --verbose,
--trace, --trace-ascii and --fail-early.
For example, you can do both a GET and a POST in a single
command line:
See also -Z, --parallel and -K, --config.
--no-alpn
(HTTPS) Disable the ALPN TLS extension. ALPN is enabled by
default if libcurl was built with an SSL library that supports
ALPN. ALPN is used by a libcurl that supports HTTP/2 to
negotiate HTTP/2 support with the server during https sessions.
Note that this is the negated option name documented. You can
use --alpn to enable ALPN.
Providing --no-alpn multiple times has no extra effect. Disable
it again with --alpn.
Example:
curl --no-alpn https://example.com
See also --no-npn and --http2. --no-alpn requires that the
underlying libcurl was built to support TLS.
-N, --no-buffer
Disables the buffering of the output stream. In normal work
situations, curl uses a standard buffered output stream that has
the effect that it outputs the data in chunks, not necessarily
exactly when the data arrives. Using this option disables that
buffering.
Note that this is the negated option name documented. You can
use --buffer to enable buffering again.
Providing -N, --no-buffer multiple times has no extra effect.
Disable it again with --buffer.
Example:
curl --no-buffer https://example.com
See also -#, --progress-bar.
--no-clobber
When used in conjunction with the -o, --output, -J,
--remote-header-name, -O, --remote-name, or --remote-name-all
options, curl avoids overwriting files that already exist.
Instead, a dot and a number gets appended to the name of the
file that would be created, up to filename.100 after which it
does not create any file.
Note that this is the negated option name documented. You can
thus use --clobber to enforce the clobbering, even if -J,
--remote-header-name is specified.
Providing --no-clobber multiple times has no extra effect.
Disable it again with --clobber.
Example:
curl --no-clobber --output local/dir/file https://example.com
See also -o, --output and -O, --remote-name. Added in 7.83.0.
Providing --no-keepalive multiple times has no extra effect.
Disable it again with --keepalive.
Example:
curl --no-keepalive https://example.com
See also --keepalive-time.
--no-npn
(HTTPS) curl never uses NPN, this option has no effect (added in
7.86.0).
Disable the NPN TLS extension. NPN is enabled by default if
libcurl was built with an SSL library that supports NPN. NPN is
used by a libcurl that supports HTTP/2 to negotiate HTTP/2
support with the server during https sessions.
Providing --no-npn multiple times has no extra effect. Disable
it again with --npn.
Example:
curl --no-npn https://example.com
See also --no-alpn and --http2. --no-npn requires that the
underlying libcurl was built to support TLS.
--no-progress-meter
Option to switch off the progress meter output without muting or
otherwise affecting warning and informational messages like -s,
--silent does.
Note that this is the negated option name documented. You can
thus use --progress-meter to enable the progress meter again.
Providing --no-progress-meter multiple times has no extra
effect. Disable it again with --progress-meter.
Example:
curl --no-progress-meter -o store https://example.com
See also -v, --verbose and -s, --silent. Added in 7.67.0.
--no-sessionid
(TLS) Disable curl's use of SSL session-ID caching. By default
all transfers are done using the cache. Note that while nothing
should ever get hurt by attempting to reuse SSL session-IDs,
there seem to be broken SSL implementations in the wild that may
require you to disable this in order for you to succeed.
Note that this is the negated option name documented. You can
thus use --sessionid to enforce session-ID caching.
Providing --no-sessionid multiple times has no extra effect.
Disable it again with --sessionid.
Example:
curl --no-sessionid https://example.com
See also -k, --insecure.
local.com would match local.com, local.com:80, and
www.local.com, but not www.notlocal.com.
This option overrides the environment variables that disable the
proxy ('no_proxy' and 'NO_PROXY') (added in 7.53.0). If there is
an environment variable disabling a proxy, you can set the no
proxy list to "" to override it.
IP addresses specified to this option can be provided using CIDR
notation (added in 7.86.0): an appended slash and number
specifies the number of "network bits" out of the address to use
in the comparison. For example "192.168.0.0/16" would match all
addresses starting with "192.168".
If --noproxy is provided several times, the last set value is
used.
Example:
curl --noproxy "www.example" https://example.com
See also -x, --proxy.
--ntlm-wb
(HTTP) Enables NTLM much in the style --ntlm does, but hand over
the authentication to the separate binary ntlmauth application
that is executed when needed.
Providing --ntlm-wb multiple times has no extra effect.
Example:
curl --ntlm-wb -u user:password https://example.com
See also --ntlm and --proxy-ntlm.
--ntlm (HTTP) Enables NTLM authentication. The NTLM authentication
method was designed by Microsoft and is used by IIS web servers.
It is a proprietary protocol, reverse-engineered by clever
people and implemented in curl based on their efforts. This kind
of behavior should not be endorsed, you should encourage
everyone who uses NTLM to switch to a public and documented
authentication method instead, such as Digest.
If you want to enable NTLM for your proxy authentication, then
use --proxy-ntlm.
Providing --ntlm multiple times has no extra effect.
Example:
curl --ntlm -u user:password https://example.com
See also --proxy-ntlm. --ntlm requires that the underlying
libcurl was built to support TLS. This option is mutually
exclusive to --basic and --negotiate and --digest and --anyauth.
--oauth2-bearer <token>
(IMAP LDAP POP3 SMTP HTTP) Specify the Bearer Token for OAUTH
2.0 server authentication. The Bearer Token is used in
conjunction with the user name which can be specified as part of
the --url or -u, --user options.
Example:
curl --oauth2-bearer "mF_9.B5f-4.1JqM" https://example.com
See also --basic, --ntlm and --digest.
--output-dir <dir>
This option specifies the directory in which files should be
stored, when -O, --remote-name or -o, --output are used.
The given output directory is used for all URLs and output
options on the command line, up until the first -:, --next.
If the specified target directory does not exist, the operation
fails unless --create-dirs is also used.
If --output-dir is provided several times, the last set value is
used.
Example:
curl --output-dir "tmp" -O https://example.com
See also -O, --remote-name and -J, --remote-header-name. Added
in 7.73.0.
-o, --output <file>
Write output to <file> instead of stdout. If you are using {} or
[] to fetch multiple documents, you should quote the URL and you
can use '#' followed by a number in the <file> specifier. That
variable is replaced with the current string for the URL being
fetched. Like in:
curl "http://{one,two}.example.com" -o "file_#1.txt"
or use several variables like:
curl "http://{site,host}.host[1-5].example" -o "#1_#2"
You may use this option as many times as the number of URLs you
have. For example, if you specify two URLs on the same command
line, you can use it like this:
curl -o aa example.com -o bb example.net
and the order of the -o options and the URLs does not matter,
just that the first -o is for the first URL and so on, so the
above command line can also be written as
curl example.com example.net -o aa -o bb
See also the --create-dirs option to create the local
directories dynamically. Specifying the output as '-' (a single
dash) passes the output to stdout.
To suppress response bodies, you can redirect output to
/dev/null:
curl example.com -o /dev/null
Or for Windows:
curl "http://{one,two}.example.com" -o "file_#1.txt"
curl "http://{site,host}.host[1-5].example" -o "#1_#2"
curl -o file https://example.com -o file2 https://example.net
See also -O, --remote-name, --remote-name-all and -J,
--remote-header-name.
--parallel-immediate
When doing parallel transfers, this option instructs curl that
it should rather prefer opening up more connections in parallel
at once rather than waiting to see if new transfers can be added
as multiplexed streams on another connection.
This option is global and does not need to be specified for each
use of --next.
Providing --parallel-immediate multiple times has no extra
effect. Disable it again with --no-parallel-immediate.
Example:
curl --parallel-immediate -Z https://example.com -o file1 https://example.com -o file2
See also -Z, --parallel and --parallel-max. Added in 7.68.0.
--parallel-max <num>
When asked to do parallel transfers, using -Z, --parallel, this
option controls the maximum amount of transfers to do
simultaneously.
This option is global and does not need to be specified for each
use of -:, --next.
The default is 50.
If --parallel-max is provided several times, the last set value
is used.
Example:
curl --parallel-max 100 -Z https://example.com ftp://example.com/
See also -Z, --parallel. Added in 7.66.0.
-Z, --parallel
Makes curl perform its transfers in parallel as compared to the
regular serial manner.
This option is global and does not need to be specified for each
use of --next.
Providing -Z, --parallel multiple times has no extra effect.
Disable it again with --no-parallel.
Example:
curl --parallel https://example.com -o file1 https://example.com -o file2
See also -:, --next and -v, --verbose. Added in 7.66.0.
--pass <phrase>
(SSH TLS) Passphrase for the private key.
--path-as-is
Tell curl to not handle sequences of /../ or /./ in the given
URL path. Normally curl squashes or merges them according to
standards but with this option set you tell it not to do that.
Providing --path-as-is multiple times has no extra effect.
Disable it again with --no-path-as-is.
Example:
curl --path-as-is https://example.com/../../etc/passwd
See also --request-target.
--pinnedpubkey <hashes>
(TLS) Tells curl to use the specified public key file (or
hashes) to verify the peer. This can be a path to a file which
contains a single public key in PEM or DER format, or any number
of base64 encoded sha256 hashes preceded by 'sha256//' and
separated by ';'.
When negotiating a TLS or SSL connection, the server sends a
certificate indicating its identity. A public key is extracted
from this certificate and if it does not exactly match the
public key provided to this option, curl aborts the connection
before sending or receiving any data.
This option is independent of option -k, --insecure. If you use
both options together then the peer is still verified by public
key.
PEM/DER support:
OpenSSL and GnuTLS, wolfSSL (added in 7.43.0), mbedTLS , Secure
Transport macOS 10.7+/iOS 10+ (7.54.1), Schannel (7.58.1)
sha256 support:
OpenSSL, GnuTLS and wolfSSL, mbedTLS (added in 7.47.0), Secure
Transport macOS 10.7+/iOS 10+ (7.54.1), Schannel (7.58.1)
Other SSL backends not supported.
If --pinnedpubkey is provided several times, the last set value
is used.
Examples:
curl --pinnedpubkey keyfile https://example.com
curl --pinnedpubkey 'sha256//ce118b51897f4452dc' https://example.com
See also --hostpubsha256.
--post301
(HTTP) Tells curl to respect RFC 7231/6.4.2 and not convert POST
requests into GET requests when following a 301 redirection. The
non-RFC behavior is ubiquitous in web browsers, so curl does the
conversion by default to maintain consistency. However, a server
may require a POST to remain a POST after such a redirection.
This option is meaningful only when using -L, --location.
See also --post302, --post303 and -L, --location.
--post302
(HTTP) Tells curl to respect RFC 7231/6.4.3 and not convert POST
requests into GET requests when following a 302 redirection. The
non-RFC behavior is ubiquitous in web browsers, so curl does the
conversion by default to maintain consistency. However, a server
may require a POST to remain a POST after such a redirection.
This option is meaningful only when using -L, --location.
Providing --post302 multiple times has no extra effect. Disable
it again with --no-post302.
Example:
curl --post302 --location -d "data" https://example.com
See also --post301, --post303 and -L, --location.
--post303
(HTTP) Tells curl to violate RFC 7231/6.4.4 and not convert POST
requests into GET requests when following 303 redirections. A
server may require a POST to remain a POST after a 303
redirection. This option is meaningful only when using -L,
--location.
Providing --post303 multiple times has no extra effect. Disable
it again with --no-post303.
Example:
curl --post303 --location -d "data" https://example.com
See also --post302, --post301 and -L, --location.
--preproxy [protocol://]host[:port]
Use the specified SOCKS proxy before connecting to an HTTP or
HTTPS -x, --proxy. In such a case curl first connects to the
SOCKS proxy and then connects (through SOCKS) to the HTTP or
HTTPS proxy. Hence pre proxy.
The pre proxy string should be specified with a protocol://
prefix to specify alternative proxy protocols. Use socks4://,
socks4a://, socks5:// or socks5h:// to request the specific
SOCKS version to be used. No protocol specified makes curl
default to SOCKS4.
If the port number is not specified in the proxy string, it is
assumed to be 1080.
User and password that might be provided in the proxy string are
URL decoded by curl. This allows you to pass in special
characters such as @ by using %40 or pass in a colon with %3a.
If --preproxy is provided several times, the last set value is
used.
Example:
curl --preproxy socks5://proxy.example -x http://http.example https://example.com
See also -x, --proxy and --socks5. Added in 7.52.0.
For transfers without a known size, there is a space ship
(-=o=-) that moves back and forth but only while data is being
transferred, with a set of flying hash sign symbols on top.
This option is global and does not need to be specified for each
use of --next.
Providing -#, --progress-bar multiple times has no extra effect.
Disable it again with --no-progress-bar.
Example:
curl -# -O https://example.com
See also --styled-output.
--proto-default <protocol>
Tells curl to use protocol for any URL missing a scheme name.
An unknown or unsupported protocol causes error
CURLE_UNSUPPORTED_PROTOCOL (1).
This option does not change the default proxy protocol (http).
Without this option set, curl guesses protocol based on the host
name, see --url for details.
If --proto-default is provided several times, the last set value
is used.
Example:
curl --proto-default https ftp.example.com
See also --proto and --proto-redir.
--proto-redir <protocols>
Tells curl to limit what protocols it may use on redirect.
Protocols denied by --proto are not overridden by this option.
See --proto for how protocols are represented.
Example, allow only HTTP and HTTPS on redirect:
curl --proto-redir -all,http,https http://example.com
By default curl only allows HTTP, HTTPS, FTP and FTPS on
redirects (added in 7.65.2). Specifying all or +all enables all
protocols on redirects, which is not good for security.
If --proto-redir is provided several times, the last set value
is used.
Example:
curl --proto-redir =http,https https://example.com
See also --proto.
--proto <protocols>
Tells curl to limit what protocols it may use for transfers.
Protocols are evaluated left to right, are comma separated, and
are each a protocol name or 'all', optionally prefixed by zero
= Permit only this protocol (ignoring the list already
permitted), though subject to later modification by
subsequent entries in the comma separated list.
For example:
--proto -ftps uses the default protocols, but disables ftps
--proto -all,https,+http
only enables http and https
--proto =http,https
also only enables http and https
Unknown and disabled protocols produce a warning. This allows
scripts to safely rely on being able to disable potentially
dangerous protocols, without relying upon support for that
protocol being built into curl to avoid an error.
This option can be used multiple times, in which case the effect
is the same as concatenating the protocols into one instance of
the option.
If --proto is provided several times, the last set value is
used.
Example:
curl --proto =http,https,sftp https://example.com
See also --proto-redir and --proto-default.
--proxy-anyauth
Tells curl to pick a suitable authentication method when
communicating with the given HTTP proxy. This might cause an
extra request/response round-trip.
Providing --proxy-anyauth multiple times has no extra effect.
Example:
curl --proxy-anyauth --proxy-user user:passwd -x proxy https://example.com
See also -x, --proxy, --proxy-basic and --proxy-digest.
--proxy-basic
Tells curl to use HTTP Basic authentication when communicating
with the given proxy. Use --basic for enabling HTTP Basic with a
remote host. Basic is the default authentication method curl
uses with proxies.
Providing --proxy-basic multiple times has no extra effect.
Example:
curl --proxy-basic --proxy-user user:passwd -x proxy https://example.com
See also -x, --proxy, --proxy-anyauth and --proxy-digest.
--proxy-ca-native
(TLS) Tells curl to use the CA store from the native operating
curl built with wolfSSL also supports this option (added in
8.3.0).
Providing --proxy-ca-native multiple times has no extra effect.
Disable it again with --no-proxy-ca-native.
Example:
curl --ca-native https://example.com
See also --cacert, --capath and -k, --insecure. Added in 8.2.0.
--proxy-cacert <file>
Same as --cacert but used in HTTPS proxy context.
If --proxy-cacert is provided several times, the last set value
is used.
Example:
curl --proxy-cacert CA-file.txt -x https://proxy https://example.com
See also --proxy-capath, --cacert, --capath and -x, --proxy.
Added in 7.52.0.
--proxy-capath <dir>
Same as --capath but used in HTTPS proxy context.
If --proxy-capath is provided several times, the last set value
is used.
Example:
curl --proxy-capath /local/directory -x https://proxy https://example.com
See also --proxy-cacert, -x, --proxy and --capath. Added in
7.52.0.
--proxy-cert-type <type>
Same as --cert-type but used in HTTPS proxy context.
If --proxy-cert-type is provided several times, the last set
value is used.
Example:
curl --proxy-cert-type PEM --proxy-cert file -x https://proxy https://example.com
See also --proxy-cert. Added in 7.52.0.
--proxy-cert <cert[:passwd]>
Same as -E, --cert but used in HTTPS proxy context.
If --proxy-cert is provided several times, the last set value is
used.
Example:
curl --proxy-cert file -x https://proxy https://example.com
See also --proxy-cert-type. Added in 7.52.0.
--proxy-ciphers <list>
If --proxy-ciphers is provided several times, the last set value
is used.
Example:
curl --proxy-ciphers ECDHE-ECDSA-AES256-CCM8 -x https://proxy https://example.com
See also --ciphers, --curves and -x, --proxy. Added in 7.52.0.
--proxy-crlfile <file>
Same as --crlfile but used in HTTPS proxy context.
If --proxy-crlfile is provided several times, the last set value
is used.
Example:
curl --proxy-crlfile rejects.txt -x https://proxy https://example.com
See also --crlfile and -x, --proxy. Added in 7.52.0.
--proxy-digest
Tells curl to use HTTP Digest authentication when communicating
with the given proxy. Use --digest for enabling HTTP Digest with
a remote host.
Providing --proxy-digest multiple times has no extra effect.
Example:
curl --proxy-digest --proxy-user user:passwd -x proxy https://example.com
See also -x, --proxy, --proxy-anyauth and --proxy-basic.
--proxy-header <header/@file>
(HTTP) Extra header to include in the request when sending HTTP
to a proxy. You may specify any number of extra headers. This is
the equivalent option to -H, --header but is for proxy
communication only like in CONNECT requests when you want a
separate header sent to the proxy to what is sent to the actual
remote host.
curl makes sure that each header you add/replace is sent with
the proper end-of-line marker, you should thus not add that as a
part of the header content: do not add newlines or carriage
returns, they only mess things up for you.
Headers specified with this option are not included in requests
that curl knows are not be sent to a proxy.
This option can take an argument in @filename style, which then
adds a header for each line in the input file (added in 7.55.0).
Using @- makes curl read the headers from stdin.
This option can be used multiple times to add/replace/remove
multiple headers.
--proxy-header can be used several times in a command line
Examples:
curl --proxy-header "X-First-Name: Joe" -x http://proxy https://example.com
proxy. The proxy might still only offer HTTP/1 and then curl
sticks to using that version.
This has no effect for any other kinds of proxies.
Providing --proxy-http2 multiple times has no extra effect.
Disable it again with --no-proxy-http2.
Example:
curl --proxy-http2 -x proxy https://example.com
See also -x, --proxy. --proxy-http2 requires that the underlying
libcurl was built to support HTTP/2. Added in 8.1.0.
--proxy-insecure
Same as -k, --insecure but used in HTTPS proxy context.
Providing --proxy-insecure multiple times has no extra effect.
Disable it again with --no-proxy-insecure.
Example:
curl --proxy-insecure -x https://proxy https://example.com
See also -x, --proxy and -k, --insecure. Added in 7.52.0.
--proxy-key-type <type>
Same as --key-type but used in HTTPS proxy context.
If --proxy-key-type is provided several times, the last set
value is used.
Example:
curl --proxy-key-type DER --proxy-key here -x https://proxy https://example.com
See also --proxy-key and -x, --proxy. Added in 7.52.0.
--proxy-key <key>
Same as --key but used in HTTPS proxy context.
If --proxy-key is provided several times, the last set value is
used.
Example:
curl --proxy-key here -x https://proxy https://example.com
See also --proxy-key-type and -x, --proxy. Added in 7.52.0.
--proxy-negotiate
Tells curl to use HTTP Negotiate (SPNEGO) authentication when
communicating with the given proxy. Use --negotiate for enabling
HTTP Negotiate (SPNEGO) with a remote host.
Providing --proxy-negotiate multiple times has no extra effect.
Example:
curl --proxy-negotiate --proxy-user user:passwd -x proxy https://example.com
See also --proxy-anyauth and --proxy-basic.
Example:
curl --proxy-ntlm --proxy-user user:passwd -x http://proxy https://example.com
See also --proxy-negotiate and --proxy-anyauth.
--proxy-pass <phrase>
Same as --pass but used in HTTPS proxy context.
If --proxy-pass is provided several times, the last set value is
used.
Example:
curl --proxy-pass secret --proxy-key here -x https://proxy https://example.com
See also -x, --proxy and --proxy-key. Added in 7.52.0.
--proxy-pinnedpubkey <hashes>
(TLS) Tells curl to use the specified public key file (or
hashes) to verify the proxy. This can be a path to a file which
contains a single public key in PEM or DER format, or any number
of base64 encoded sha256 hashes preceded by 'sha256//' and
separated by ';'.
When negotiating a TLS or SSL connection, the server sends a
certificate indicating its identity. A public key is extracted
from this certificate and if it does not exactly match the
public key provided to this option, curl aborts the connection
before sending or receiving any data.
If --proxy-pinnedpubkey is provided several times, the last set
value is used.
Examples:
curl --proxy-pinnedpubkey keyfile https://example.com
curl --proxy-pinnedpubkey 'sha256//ce118b51897f4452dc' https://example.com
See also --pinnedpubkey and -x, --proxy. Added in 7.59.0.
--proxy-service-name <name>
This option allows you to change the service name for proxy
negotiation.
If --proxy-service-name is provided several times, the last set
value is used.
Example:
curl --proxy-service-name "shrubbery" -x proxy https://example.com
See also --service-name and -x, --proxy.
--proxy-ssl-allow-beast
Same as --ssl-allow-beast but used in HTTPS proxy context.
Providing --proxy-ssl-allow-beast multiple times has no extra
effect. Disable it again with --no-proxy-ssl-allow-beast.
Example:
curl --proxy-ssl-allow-beast -x https://proxy https://example.com
--no-proxy-ssl-auto-client-cert.
Example:
curl --proxy-ssl-auto-client-cert -x https://proxy https://example.com
See also --ssl-auto-client-cert and -x, --proxy. Added in
7.77.0.
--proxy-tls13-ciphers <ciphersuite list>
(TLS) Specifies which cipher suites to use in the connection to
your HTTPS proxy when it negotiates TLS 1.3. The list of ciphers
suites must specify valid ciphers. Read up on TLS 1.3 cipher
suite details on this URL:
https://curl.se/docs/ssl-ciphers.html
This option is currently used only when curl is built to use
OpenSSL 1.1.1 or later. If you are using a different SSL backend
you can try setting TLS 1.3 cipher suites by using the
--proxy-ciphers option.
If --proxy-tls13-ciphers is provided several times, the last set
value is used.
Example:
curl --proxy-tls13-ciphers TLS_AES_128_GCM_SHA256 -x proxy https://example.com
See also --tls13-ciphers, --curves and --proxy-ciphers. Added in
7.61.0.
--proxy-tlsauthtype <type>
Same as --tlsauthtype but used in HTTPS proxy context.
If --proxy-tlsauthtype is provided several times, the last set
value is used.
Example:
curl --proxy-tlsauthtype SRP -x https://proxy https://example.com
See also -x, --proxy and --proxy-tlsuser. Added in 7.52.0.
--proxy-tlspassword <string>
Same as --tlspassword but used in HTTPS proxy context.
If --proxy-tlspassword is provided several times, the last set
value is used.
Example:
curl --proxy-tlspassword passwd -x https://proxy https://example.com
See also -x, --proxy and --proxy-tlsuser. Added in 7.52.0.
--proxy-tlsuser <name>
Same as --tlsuser but used in HTTPS proxy context.
If --proxy-tlsuser is provided several times, the last set value
is used.
Example:
Providing --proxy-tlsv1 multiple times has no extra effect.
Example:
curl --proxy-tlsv1 -x https://proxy https://example.com
See also -x, --proxy. Added in 7.52.0.
-U, --proxy-user <user:password>
Specify the user name and password to use for proxy
authentication.
If you use a Windows SSPI-enabled curl binary and do either
Negotiate or NTLM authentication then you can tell curl to
select the user name and password from your environment by
specifying a single colon with this option: "-U :".
On systems where it works, curl hides the given option argument
from process listings. This is not enough to protect credentials
from possibly getting seen by other users on the same system as
they still are visible for a moment before cleared. Such
sensitive data should be retrieved from a file instead or
similar and never used in clear text in a command line.
If -U, --proxy-user is provided several times, the last set
value is used.
Example:
curl --proxy-user name:pwd -x proxy https://example.com
See also --proxy-pass.
-x, --proxy [protocol://]host[:port]
Use the specified proxy.
The proxy string can be specified with a protocol:// prefix. No
protocol specified or http:// it is treated as an HTTP proxy.
Use socks4://, socks4a://, socks5:// or socks5h:// to request a
specific SOCKS version to be used.
Unix domain sockets are supported for socks proxy. Set localhost
for the host part. e.g. socks5h://localhost/path/to/socket.sock
HTTPS proxy support works set with the https:// protocol prefix
for OpenSSL and GnuTLS (added in 7.52.0). It also works for
BearSSL, mbedTLS, rustls, Schannel, Secure Transport and wolfSSL
(added in 7.87.0).
Unrecognized and unsupported proxy protocols cause an error
(added in 7.52.0). Ancient curl versions ignored unknown
schemes and used http:// instead.
If the port number is not specified in the proxy string, it is
assumed to be 1080.
This option overrides existing environment variables that set
the proxy to use. If there is an environment variable setting a
proxy, you can set proxy to "" to override it.
All operations that are performed over an HTTP proxy are
characters such as @ by using %40 or pass in a colon with %3a.
The proxy host can be specified the same way as the proxy
environment variables, including the protocol prefix (http://)
and the embedded user + password.
When a proxy is used, the active FTP mode as set with -P,
--ftp-port, cannot be used.
If -x, --proxy is provided several times, the last set value is
used.
Example:
curl --proxy http://proxy.example https://example.com
See also --socks5 and --proxy-basic.
--proxy1.0 <host[:port]>
Use the specified HTTP 1.0 proxy. If the port number is not
specified, it is assumed at port 1080.
The only difference between this and the HTTP proxy option -x,
--proxy, is that attempts to use CONNECT through the proxy
specifies an HTTP 1.0 protocol instead of the default HTTP 1.1.
Providing --proxy1.0 multiple times has no extra effect.
Example:
curl --proxy1.0 -x http://proxy https://example.com
See also -x, --proxy, --socks5 and --preproxy.
-p, --proxytunnel
When an HTTP proxy is used -x, --proxy, this option makes curl
tunnel the traffic through the proxy. The tunnel approach is
made with the HTTP proxy CONNECT request and requires that the
proxy allows direct connect to the remote port number curl wants
to tunnel through to.
To suppress proxy CONNECT response headers when curl is set to
output headers use --suppress-connect-headers.
Providing -p, --proxytunnel multiple times has no extra effect.
Disable it again with --no-proxytunnel.
Example:
curl --proxytunnel -x http://proxy https://example.com
See also -x, --proxy.
--pubkey <key>
(SFTP SCP) Public key file name. Allows you to provide your
public key in this separate file.
curl attempts to automatically extract the public key from the
private key file, so passing this option is generally not
required. Note that this public key extraction requires libcurl
to be linked against a copy of libssh2 1.2.8 or higher that is
itself linked against OpenSSL.
See also --pass.
-Q, --quote <command>
(FTP SFTP) Send an arbitrary command to the remote FTP or SFTP
server. Quote commands are sent BEFORE the transfer takes place
(just after the initial PWD command in an FTP transfer, to be
exact). To make commands take place after a successful transfer,
prefix them with a dash '-'.
(FTP only) To make commands be sent after curl has changed the
working directory, just before the file transfer command(s),
prefix the command with a '+'. This is not performed when a
directory listing is performed.
You may specify any number of commands.
By default curl stops at first failure. To make curl continue
even if the command fails, prefix the command with an asterisk
(*). Otherwise, if the server returns failure for one of the
commands, the entire operation is aborted.
You must send syntactically correct FTP commands as RFC 959
defines to FTP servers, or one of the commands listed below to
SFTP servers.
SFTP is a binary protocol. Unlike for FTP, curl interprets SFTP
quote commands itself before sending them to the server. File
names may be quoted shell-style to embed spaces or special
characters. Following is the list of all supported SFTP quote
commands:
"atime date file"
The atime command sets the last access time of the file
named by the file operand. The <date expression> can be
all sorts of date strings, see the curl_getdate(3) man
page for date expression details. (Added in 7.73.0)
"chgrp group file"
The chgrp command sets the group ID of the file named by
the file operand to the group ID specified by the group
operand. The group operand is a decimal integer group ID.
"chmod mode file"
The chmod command modifies the file mode bits of the
specified file. The mode operand is an octal integer mode
number.
"chown user file"
The chown command sets the owner of the file named by the
file operand to the user ID specified by the user
operand. The user operand is a decimal integer user ID.
"ln source_file target_file"
The ln and symlink commands create a symbolic link at the
target_file location pointing to the source_file
location.
"mkdir directory_name"
The mkdir command creates the directory named by the
"pwd" The pwd command returns the absolute path name of the
current working directory.
"rename source target"
The rename command renames the file or directory named by
the source operand to the destination path named by the
target operand.
"rm file"
The rm command removes the file specified by the file
operand.
"rmdir directory"
The rmdir command removes the directory entry specified
by the directory operand, provided it is empty.
"symlink source_file target_file"
See ln.
-Q, --quote can be used several times in a command line
Example:
curl --quote "DELE file" ftp://example.com/foo
See also -X, --request.
--random-file <file>
Deprecated option. This option is ignored (added in 7.84.0).
Prior to that it only had an effect on curl if built to use old
versions of OpenSSL.
Specify the path name to file containing random data. The data
may be used to seed the random engine for SSL connections.
If --random-file is provided several times, the last set value
is used.
Example:
curl --random-file rubbish https://example.com
See also --egd-file.
-r, --range <range>
(HTTP FTP SFTP FILE) Retrieve a byte range (i.e. a partial
document) from an HTTP/1.1, FTP or SFTP server or a local FILE.
Ranges can be specified in a number of ways.
0-499 specifies the first 500 bytes
500-999 specifies the second 500 bytes
-500 specifies the last 500 bytes
9500- specifies the bytes from offset 9500 and forward
0-0,-1 specifies the first and last byte only(*)(HTTP)
Only digit characters (0-9) are valid in the 'start' and 'stop'
fields of the 'start-stop' range syntax. If a non-digit
character is given in the range, the server's response is
unspecified, depending on the server's configuration.
Many HTTP/1.1 servers do not have this feature enabled, so that
when you attempt to get a range, curl instead gets the whole
document.
FTP and SFTP range downloads only support the simple
'start-stop' syntax (optionally with one of the numbers
omitted). FTP use depends on the extended FTP command SIZE.
If -r, --range is provided several times, the last set value is
used.
Example:
curl --range 22-44 https://example.com
See also -C, --continue-at and -a, --append.
--rate <max request rate>
Specify the maximum transfer frequency you allow curl to use -
in number of transfer starts per time unit (sometimes called
request rate). Without this option, curl starts the next
transfer as fast as possible.
If given several URLs and a transfer completes faster than the
allowed rate, curl waits until the next transfer is started to
maintain the requested rate. This option has no effect when -Z,
--parallel is used.
The request rate is provided as "N/U" where N is an integer
number and U is a time unit. Supported units are 's' (second),
'm' (minute), 'h' (hour) and 'd' /(day, as in a 24 hour unit).
The default time unit, if no "/U" is provided, is number of
transfers per hour.
If curl is told to allow 10 requests per minute, it does not
start the next request until 6 seconds have elapsed since the
previous transfer was started.
This function uses millisecond resolution. If the allowed
frequency is set more than 1000 per second, it instead runs
unrestricted.
When retrying transfers, enabled with --retry, the separate
retry delay logic is used and not this setting.
This option is global and does not need to be specified for each
use of --next.
If --rate is provided several times, the last set value is used.
Examples:
curl --rate 2/s https://example.com ...
curl --rate 3/h https://example.com ...
curl --rate 14/m https://example.com ...
again with --no-raw.
Example:
curl --raw https://example.com
See also --tr-encoding.
-e, --referer <URL>
(HTTP) Sends the "Referrer Page" information to the HTTP server.
This can also be set with the -H, --header flag of course. When
used with -L, --location you can append ";auto" to the -e,
--referer URL to make curl automatically set the previous URL
when it follows a Location: header. The ";auto" string can be
used alone, even if you do not set an initial -e, --referer.
If -e, --referer is provided several times, the last set value
is used.
Examples:
curl --referer "https://fake.example" https://example.com
curl --referer "https://fake.example;auto" -L https://example.com
curl --referer ";auto" -L https://example.com
See also -A, --user-agent and -H, --header.
-J, --remote-header-name
(HTTP) This option tells the -O, --remote-name option to use the
server-specified Content-Disposition filename instead of
extracting a filename from the URL. If the server-provided file
name contains a path, that is stripped off before the file name
is used.
The file is saved in the current directory, or in the directory
specified with --output-dir.
If the server specifies a file name and a file with that name
already exists in the destination directory, it is not
overwritten and an error occurs - unless you allow it by using
the --clobber option. If the server does not specify a file name
then this option has no effect.
There is no attempt to decode %-sequences (yet) in the provided
file name, so this option may provide you with rather unexpected
file names.
This feature uses the name from the "filename" field, it does
not yet support the "filename*" field (filenames with explicit
character sets).
WARNING: Exercise judicious use of this option, especially on
Windows. A rogue server could send you the name of a DLL or
other file that could be loaded automatically by Windows or some
third party software.
Providing -J, --remote-header-name multiple times has no extra
effect. Disable it again with --no-remote-header-name.
Example:
curl -OJ https://example.com/file
--remote-name-all has been used, you must use "-o -" or
--no-remote-name.
Providing --remote-name-all multiple times has no extra effect.
Disable it again with --no-remote-name-all.
Example:
curl --remote-name-all ftp://example.com/file1 ftp://example.com/file2
See also -O, --remote-name.
-O, --remote-name
Write output to a local file named like the remote file we get.
(Only the file part of the remote file is used, the path is cut
off.)
The file is saved in the current working directory. If you want
the file saved in a different directory, make sure you change
the current working directory before invoking curl with this
option or use --output-dir.
The remote file name to use for saving is extracted from the
given URL, nothing else, and if it already exists it is
overwritten. If you want the server to be able to choose the
file name refer to -J, --remote-header-name which can be used in
addition to this option. If the server chooses a file name and
that name already exists it is not overwritten.
There is no URL decoding done on the file name. If it has %20 or
other URL encoded parts of the name, they end up as-is as file
name.
You may use this option as many times as the number of URLs you
have.
-O, --remote-name can be used several times in a command line
Example:
curl -O https://example.com/filename
See also --remote-name-all, --output-dir and -J,
--remote-header-name.
-R, --remote-time
Makes curl attempt to figure out the timestamp of the remote
file that is getting downloaded, and if that is available make
the local file get that same timestamp.
Providing -R, --remote-time multiple times has no extra effect.
Disable it again with --no-remote-time.
Example:
curl --remote-time -o foo https://example.com
See also -O, --remote-name and -z, --time-cond.
--remove-on-error
When curl returns an error when told to save output in a local
file, this option removes that saved file before exiting. This
Example:
curl --remove-on-error -o output https://example.com
See also -f, --fail. Added in 7.83.0.
--request-target <path>
(HTTP) Tells curl to use an alternative "target" (path) instead
of using the path as provided in the URL. Particularly useful
when wanting to issue HTTP requests without leading slash or
other data that does not follow the regular URL pattern, like
"OPTIONS *".
curl passes on the verbatim string you give it its the request
without any filter or other safe guards. That includes white
space and control characters.
If --request-target is provided several times, the last set
value is used.
Example:
curl --request-target "*" -X OPTIONS https://example.com
See also -X, --request. Added in 7.55.0.
-X, --request <method>
Change the method to use when starting the transfer.
curl passes on the verbatim string you give it its the request
without any filter or other safe guards. That includes white
space and control characters.
HTTP Specifies a custom request method to use when
communicating with the HTTP server. The specified
request method is used instead of the method
otherwise used (which defaults to GET). Read the
HTTP 1.1 specification for details and
explanations. Common additional HTTP requests
include PUT and DELETE, but related technologies
like WebDAV offers PROPFIND, COPY, MOVE and more.
Normally you do not need this option. All sorts
of GET, HEAD, POST and PUT requests are rather
invoked by using dedicated command line options.
This option only changes the actual word used in
the HTTP request, it does not alter the way curl
behaves. So for example if you want to make a
proper HEAD request, using -X HEAD does not
suffice. You need to use the -I, --head option.
The method string you set with -X, --request is
used for all requests, which if you for example
use -L, --location may cause unintended
side-effects when curl does not change request
method according to the HTTP 30x response codes -
and similar.
FTP Specifies a custom FTP command to use instead of
LIST.
SMTP Specifies a custom SMTP command to use instead of
HELP or VRFY.
If -X, --request is provided several times, the last set value
is used.
Examples:
curl -X "DELETE" https://example.com
curl -X NLST ftp://example.com/
See also --request-target.
--resolve <[+]host:port:addr[,addr]...>
Provide a custom address for a specific host and port pair.
Using this, you can make the curl requests(s) use a specified
address and prevent the otherwise normally resolved address to
be used. Consider it a sort of /etc/hosts alternative provided
on the command line. The port number should be the number used
for the specific protocol the host is used for. It means you
need several entries if you want to provide address for the same
host but different ports.
By specifying '*' as host you can tell curl to resolve any host
and specific port pair to the specified address. Wildcard is
resolved last so any --resolve with a specific host and port is
used first.
The provided address set by this option is used even if -4,
--ipv4 or -6, --ipv6 is set to make curl use another IP version.
By prefixing the host with a '+' you can make the entry time out
after curl's default timeout (1 minute). Note that this only
makes sense for long running parallel transfers with a lot of
files. In such cases, if this option is used curl tries to
resolve the host as it normally would once the timeout has
expired.
Support for providing the IP address within [brackets] was added
in 7.57.0.
Support for providing multiple IP addresses per entry was added
in 7.59.0.
Support for resolving with wildcard was added in 7.64.0.
Support for the '+' prefix was was added in 7.75.0.
--resolve can be used several times in a command line
Example:
curl --resolve example.com:443:127.0.0.1 https://example.com
See also --connect-to and --alt-svc.
--retry-all-errors
Retry on any error. This option is used together with --retry.
WARNING: For server compatibility curl attempts to retry failed
flaky transfers as close as possible to how they were started,
but this is not possible with redirected input or output. For
example, before retrying it removes output data from a failed
partial transfer that was written to an output file. However
this is not true of data redirected to a | pipe or > file, which
are not reset. We strongly suggest you do not parse or record
output via redirect in combination with this option, since you
may receive duplicate data.
By default curl does not return error for transfers with an HTTP
response code that indicates an HTTP error, if the transfer was
successful. For example, if a server replies 404 Not Found and
the reply is fully received then that is not an error. When
--retry is used then curl retries on some HTTP response codes
that indicate transient HTTP errors, but that does not include
most 4xx response codes such as 404. If you want to retry on all
response codes that indicate HTTP errors (4xx and 5xx) then
combine with -f, --fail.
Providing --retry-all-errors multiple times has no extra effect.
Disable it again with --no-retry-all-errors.
Example:
curl --retry 5 --retry-all-errors https://example.com
See also --retry. Added in 7.71.0.
--retry-connrefused
In addition to the other conditions, consider ECONNREFUSED as a
transient error too for --retry. This option is used together
with --retry.
Providing --retry-connrefused multiple times has no extra
effect. Disable it again with --no-retry-connrefused.
Example:
curl --retry-connrefused --retry 7 https://example.com
See also --retry and --retry-all-errors. Added in 7.52.0.
--retry-delay <seconds>
Make curl sleep this amount of time before each retry when a
transfer has failed with a transient error (it changes the
default backoff time algorithm between retries). This option is
only interesting if --retry is also used. Setting this delay to
zero makes curl use the default backoff time.
If --retry-delay is provided several times, the last set value
is used.
Example:
curl --retry-delay 5 --retry 7 https://example.com
See also --retry.
--retry-max-time <seconds>
The retry timer is reset before the first transfer attempt.
If --retry-max-time is provided several times, the last set
value is used.
Example:
curl --retry-max-time 30 --retry 10 https://example.com
See also --retry.
--retry <num>
If a transient error is returned when curl tries to perform a
transfer, it retries this number of times before giving up.
Setting the number to 0 makes curl do no retries (which is the
default). Transient error means either: a timeout, an FTP 4xx
response code or an HTTP 408, 429, 500, 502, 503 or 504 response
code.
When curl is about to retry a transfer, it first waits one
second and then for all forthcoming retries it doubles the
waiting time until it reaches 10 minutes which then remains
delay between the rest of the retries. By using --retry-delay
you disable this exponential backoff algorithm. See also
--retry-max-time to limit the total time allowed for retries.
curl complies with the Retry-After: response header if one was
present to know when to issue the next retry (added in 7.66.0).
If --retry is provided several times, the last set value is
used.
Example:
curl --retry 7 https://example.com
See also --retry-max-time.
--sasl-authzid <identity>
Use this authorization identity (authzid), during SASL PLAIN
authentication, in addition to the authentication identity
(authcid) as specified by -u, --user.
If the option is not specified, the server derives the authzid
from the authcid, but if specified, and depending on the server
implementation, it may be used to access another user's inbox,
that the user has been granted access to, or a shared mailbox
for example.
If --sasl-authzid is provided several times, the last set value
is used.
Example:
curl --sasl-authzid zid imap://example.com/
See also --login-options. Added in 7.66.0.
--sasl-ir
Enable initial response in SASL authentication.
Providing --sasl-ir multiple times has no extra effect. Disable
it again with --no-sasl-ir.
If --service-name is provided several times, the last set value
is used.
Example:
curl --service-name sockd/server https://example.com
See also --negotiate and --proxy-service-name.
-S, --show-error
When used with -s, --silent, it makes curl show an error message
if it fails.
This option is global and does not need to be specified for each
use of --next.
Providing -S, --show-error multiple times has no extra effect.
Disable it again with --no-show-error.
Example:
curl --show-error --silent https://example.com
See also --no-progress-meter.
-s, --silent
Silent or quiet mode. Do not show progress meter or error
messages. Makes Curl mute. It still outputs the data you ask
for, potentially even to the terminal/stdout unless you redirect
it.
Use -S, --show-error in addition to this option to disable
progress meter but still show error messages.
Providing -s, --silent multiple times has no extra effect.
Disable it again with --no-silent.
Example:
curl -s https://example.com
See also -v, --verbose, --stderr and --no-progress-meter.
--socks4 <host[:port]>
Use the specified SOCKS4 proxy. If the port number is not
specified, it is assumed at port 1080. Using this socket type
make curl resolve the host name and passing the address on to
the proxy.
To specify proxy on a unix domain socket, use localhost for
host, e.g. socks4://localhost/path/to/socket.sock
This option overrides any previous use of -x, --proxy, as they
are mutually exclusive.
This option is superfluous since you can specify a socks4 proxy
with -x, --proxy using a socks4:// protocol prefix.
--preproxy can be used to specify a SOCKS proxy at the same time
proxy is used with an HTTP/HTTPS proxy (added in 7.52.0). In
such a case, curl first connects to the SOCKS proxy and then
See also --socks4a, --socks5 and --socks5-hostname.
--socks4a <host[:port]>
Use the specified SOCKS4a proxy. If the port number is not
specified, it is assumed at port 1080. This asks the proxy to
resolve the host name.
To specify proxy on a unix domain socket, use localhost for
host, e.g. socks4a://localhost/path/to/socket.sock
This option overrides any previous use of -x, --proxy, as they
are mutually exclusive.
This option is superfluous since you can specify a socks4a proxy
with -x, --proxy using a socks4a:// protocol prefix.
--preproxy can be used to specify a SOCKS proxy at the same time
-x, --proxy is used with an HTTP/HTTPS proxy (added in 7.52.0).
In such a case, curl first connects to the SOCKS proxy and then
connects (through SOCKS) to the HTTP or HTTPS proxy.
If --socks4a is provided several times, the last set value is
used.
Example:
curl --socks4a hostname:4096 https://example.com
See also --socks4, --socks5 and --socks5-hostname.
--socks5-basic
Tells curl to use username/password authentication when
connecting to a SOCKS5 proxy. The username/password
authentication is enabled by default. Use --socks5-gssapi to
force GSS-API authentication to SOCKS5 proxies.
Providing --socks5-basic multiple times has no extra effect.
Example:
curl --socks5-basic --socks5 hostname:4096 https://example.com
See also --socks5. Added in 7.55.0.
--socks5-gssapi-nec
As part of the GSS-API negotiation a protection mode is
negotiated. RFC 1961 says in section 4.3/4.4 it should be
protected, but the NEC reference implementation does not. The
option --socks5-gssapi-nec allows the unprotected exchange of
the protection mode negotiation.
Providing --socks5-gssapi-nec multiple times has no extra
effect. Disable it again with --no-socks5-gssapi-nec.
Example:
curl --socks5-gssapi-nec --socks5 hostname:4096 https://example.com
See also --socks5.
--socks5-gssapi-service <name>
curl --socks5-gssapi-service sockd --socks5 hostname:4096 https://example.com
See also --socks5.
--socks5-gssapi
Tells curl to use GSS-API authentication when connecting to a
SOCKS5 proxy. The GSS-API authentication is enabled by default
(if curl is compiled with GSS-API support). Use --socks5-basic
to force username/password authentication to SOCKS5 proxies.
Providing --socks5-gssapi multiple times has no extra effect.
Disable it again with --no-socks5-gssapi.
Example:
curl --socks5-gssapi --socks5 hostname:4096 https://example.com
See also --socks5. Added in 7.55.0.
--socks5-hostname <host[:port]>
Use the specified SOCKS5 proxy (and let the proxy resolve the
host name). If the port number is not specified, it is assumed
at port 1080.
To specify proxy on a unix domain socket, use localhost for
host, e.g. socks5h://localhost/path/to/socket.sock
This option overrides any previous use of -x, --proxy, as they
are mutually exclusive.
This option is superfluous since you can specify a socks5
hostname proxy with -x, --proxy using a socks5h:// protocol
prefix.
--preproxy can be used to specify a SOCKS proxy at the same time
-x, --proxy is used with an HTTP/HTTPS proxy (added in 7.52.0).
In such a case, curl first connects to the SOCKS proxy and then
connects (through SOCKS) to the HTTP or HTTPS proxy.
If --socks5-hostname is provided several times, the last set
value is used.
Example:
curl --socks5-hostname proxy.example:7000 https://example.com
See also --socks5 and --socks4a.
--socks5 <host[:port]>
Use the specified SOCKS5 proxy - but resolve the host name
locally. If the port number is not specified, it is assumed at
port 1080.
To specify proxy on a unix domain socket, use localhost for
host, e.g. socks5://localhost/path/to/socket.sock
This option overrides any previous use of -x, --proxy, as they
are mutually exclusive.
This option is superfluous since you can specify a socks5 proxy
with -x, --proxy using a socks5:// protocol prefix.
or LDAP.
If --socks5 is provided several times, the last set value is
used.
Example:
curl --socks5 proxy.example:7000 https://example.com
See also --socks5-hostname and --socks4a.
-Y, --speed-limit <speed>
If a transfer is slower than this given speed (in bytes per
second) for speed-time seconds it gets aborted. speed-time is
set with -y, --speed-time and is 30 if not set.
If -Y, --speed-limit is provided several times, the last set
value is used.
Example:
curl --speed-limit 300 --speed-time 10 https://example.com
See also -y, --speed-time, --limit-rate and -m, --max-time.
-y, --speed-time <seconds>
If a transfer runs slower than speed-limit bytes per second
during a speed-time period, the transfer is aborted. If
speed-time is used, the default speed-limit is 1 unless set with
-Y, --speed-limit.
This option controls transfers (in both directions) but does not
affect slow connects etc. If this is a concern for you, try the
--connect-timeout option.
If -y, --speed-time is provided several times, the last set
value is used.
Example:
curl --speed-limit 300 --speed-time 10 https://example.com
See also -Y, --speed-limit and --limit-rate.
--ssl-allow-beast
This option tells curl to not work around a security flaw in the
SSL3 and TLS1.0 protocols known as BEAST. If this option is not
used, the SSL layer may use workarounds known to cause
interoperability problems with some older SSL implementations.
WARNING: this option loosens the SSL security, and by using this
flag you ask for exactly that.
Providing --ssl-allow-beast multiple times has no extra effect.
Disable it again with --no-ssl-allow-beast.
Example:
curl --ssl-allow-beast https://example.com
See also --proxy-ssl-allow-beast and -k, --insecure.
--ssl-auto-client-cert
effect. Disable it again with --no-ssl-auto-client-cert.
Example:
curl --ssl-auto-client-cert https://example.com
See also --proxy-ssl-auto-client-cert. Added in 7.77.0.
--ssl-no-revoke
(Schannel) This option tells curl to disable certificate
revocation checks. WARNING: this option loosens the SSL
security, and by using this flag you ask for exactly that.
Providing --ssl-no-revoke multiple times has no extra effect.
Disable it again with --no-ssl-no-revoke.
Example:
curl --ssl-no-revoke https://example.com
See also --crlfile.
--ssl-reqd
(FTP IMAP POP3 SMTP LDAP) Require SSL/TLS for the connection.
Terminates the connection if the transfer cannot be upgraded to
use SSL/TLS.
This option is handled in LDAP (added in 7.81.0). It is fully
supported by the OpenLDAP backend and rejected by the generic
ldap backend if explicit TLS is required.
This option is unnecessary if you use a URL scheme that in
itself implies immediate and implicit use of TLS, like for FTPS,
IMAPS, POP3S, SMTPS and LDAPS. Such a transfer always fails if
the TLS handshake does not work.
This option was formerly known as --ftp-ssl-reqd.
Providing --ssl-reqd multiple times has no extra effect.
Disable it again with --no-ssl-reqd.
Example:
curl --ssl-reqd ftp://example.com
See also --ssl and -k, --insecure.
--ssl-revoke-best-effort
(Schannel) This option tells curl to ignore certificate
revocation checks when they failed due to missing/offline
distribution points for the revocation check lists.
Providing --ssl-revoke-best-effort multiple times has no extra
effect. Disable it again with --no-ssl-revoke-best-effort.
Example:
curl --ssl-revoke-best-effort https://example.com
See also --crlfile and -k, --insecure. Added in 7.70.0.
--ssl (FTP IMAP POP3 SMTP LDAP) Warning: this is considered an
insecure option. Consider using --ssl-reqd instead to be sure
This option is handled in LDAP (added in 7.81.0). It is fully
supported by the OpenLDAP backend and ignored by the generic
ldap backend.
Please note that a server may close the connection if the
negotiation does not succeed.
This option was formerly known as --ftp-ssl. That option name
can still be used but might be removed in a future version.
Providing --ssl multiple times has no extra effect. Disable it
again with --no-ssl.
Example:
curl --ssl pop3://example.com/
See also --ssl-reqd, -k, --insecure and --ciphers.
-2, --sslv2
(SSL) This option previously asked curl to use SSLv2, but is now
ignored (added in 7.77.0). SSLv2 is widely considered insecure
(see RFC 6176).
Providing -2, --sslv2 multiple times has no extra effect.
Example:
curl --sslv2 https://example.com
See also --http1.1 and --http2. -2, --sslv2 requires that the
underlying libcurl was built to support TLS. This option is
mutually exclusive to -3, --sslv3 and -1, --tlsv1 and --tlsv1.1
and --tlsv1.2.
-3, --sslv3
(SSL) This option previously asked curl to use SSLv3, but is now
ignored (added in 7.77.0). SSLv3 is widely considered insecure
(see RFC 7568).
Providing -3, --sslv3 multiple times has no extra effect.
Example:
curl --sslv3 https://example.com
See also --http1.1 and --http2. -3, --sslv3 requires that the
underlying libcurl was built to support TLS. This option is
mutually exclusive to -2, --sslv2 and -1, --tlsv1 and --tlsv1.1
and --tlsv1.2.
--stderr <file>
Redirect all writes to stderr to the specified file instead. If
the file name is a plain '-', it is instead written to stdout.
This option is global and does not need to be specified for each
use of --next.
If --stderr is provided several times, the last set value is
used.
Example:
off.
Styled output requires a terminal that supports bold fonts. This
feature is not present on curl for Windows due to lack of this
capability.
This option is global and does not need to be specified for each
use of --next.
Providing --styled-output multiple times has no extra effect.
Disable it again with --no-styled-output.
Example:
curl --styled-output -I https://example.com
See also -I, --head and -v, --verbose. Added in 7.61.0.
--suppress-connect-headers
When -p, --proxytunnel is used and a CONNECT request is made do
not output proxy CONNECT response headers. This option is meant
to be used with -D, --dump-header or -i, --include which are
used to show protocol headers in the output. It has no effect on
debug options such as -v, --verbose or --trace, or any
statistics.
Providing --suppress-connect-headers multiple times has no extra
effect. Disable it again with --no-suppress-connect-headers.
Example:
curl --suppress-connect-headers --include -x proxy https://example.com
See also -D, --dump-header, -i, --include and -p, --proxytunnel.
Added in 7.54.0.
--tcp-fastopen
Enable use of TCP Fast Open (RFC 7413). TCP Fast Open is a TCP
extension that allows data to get sent earlier over the
connection (before the final handshake ACK) if the client and
server have been connected previously.
Providing --tcp-fastopen multiple times has no extra effect.
Disable it again with --no-tcp-fastopen.
Example:
curl --tcp-fastopen https://example.com
See also --false-start.
--tcp-nodelay
Turn on the TCP_NODELAY option. See the curl_easy_setopt(3) man
page for details about this option.
curl sets this option by default and you need to explicitly
switch it off if you do not want it on (added in 7.50.2).
Providing --tcp-nodelay multiple times has no extra effect.
Disable it again with --no-tcp-nodelay.
TTYPE=<term> Sets the terminal type.
XDISPLOC=<X display> Sets the X display location.
NEW_ENV=<var,val> Sets an environment variable.
-t, --telnet-option can be used several times in a command line
Example:
curl -t TTYPE=vt100 telnet://example.com/
See also -K, --config.
--tftp-blksize <value>
(TFTP) Set the TFTP BLKSIZE option (must be >512). This is the
block size that curl tries to use when transferring data to or
from a TFTP server. By default 512 bytes are used.
If --tftp-blksize is provided several times, the last set value
is used.
Example:
curl --tftp-blksize 1024 tftp://example.com/file
See also --tftp-no-options.
--tftp-no-options
(TFTP) Tells curl not to send TFTP options requests.
This option improves interop with some legacy servers that do
not acknowledge or properly implement TFTP options. When this
option is used --tftp-blksize is ignored.
Providing --tftp-no-options multiple times has no extra effect.
Disable it again with --no-tftp-no-options.
Example:
curl --tftp-no-options tftp://192.168.0.1/
See also --tftp-blksize.
-z, --time-cond <time>
(HTTP FTP) Request a file that has been modified later than the
given time and date, or one that has been modified before that
time. The <date expression> can be all sorts of date strings or
if it does not match any internal ones, it is taken as a
filename and tries to get the modification date (mtime) from
<file> instead. See the curl_getdate(3) man pages for date
expression details.
Start the date expression with a dash (-) to make it request for
a document that is older than the given date/time, default is a
document that is newer than the specified date/time.
If provided a non-existing file, curl outputs a warning about
that fact and proceeds to do the transfer without a time
curl -z "-Wed 01 Sep 2021 12:18:00" https://example.com
curl -z file https://example.com
See also --etag-compare and -R, --remote-time.
--tls-max <VERSION>
(TLS) VERSION defines maximum supported TLS version. The minimum
acceptable version is set by tlsv1.0, tlsv1.1, tlsv1.2 or
tlsv1.3.
If the connection is done without TLS, this option has no
effect. This includes QUIC-using (HTTP/3) transfers.
default
Use up to recommended TLS version.
1.0 Use up to TLSv1.0.
1.1 Use up to TLSv1.1.
1.2 Use up to TLSv1.2.
1.3 Use up to TLSv1.3.
If --tls-max is provided several times, the last set value is
used.
Examples:
curl --tls-max 1.2 https://example.com
curl --tls-max 1.3 --tlsv1.2 https://example.com
See also --tlsv1.0, --tlsv1.1, --tlsv1.2 and --tlsv1.3.
--tls-max requires that the underlying libcurl was built to
support TLS. Added in 7.54.0.
--tls13-ciphers <ciphersuite list>
(TLS) Specifies which cipher suites to use in the connection if
it negotiates TLS 1.3. The list of ciphers suites must specify
valid ciphers. Read up on TLS 1.3 cipher suite details on this
URL:
https://curl.se/docs/ssl-ciphers.html
This option is currently used only when curl is built to use
OpenSSL 1.1.1 or later, or Schannel. If you are using a
different SSL backend you can try setting TLS 1.3 cipher suites
by using the --ciphers option.
If --tls13-ciphers is provided several times, the last set value
is used.
Example:
curl --tls13-ciphers TLS_AES_128_GCM_SHA256 https://example.com
See also --ciphers, --curves and --proxy-tls13-ciphers. Added in
7.61.0.
If --tlsauthtype is provided several times, the last set value
is used.
Example:
curl --tlsauthtype SRP https://example.com
See also --tlsuser.
--tlspassword <string>
Set password for use with the TLS authentication method
specified with --tlsauthtype. Requires that --tlsuser also be
set.
This option does not work with TLS 1.3.
If --tlspassword is provided several times, the last set value
is used.
Example:
curl --tlspassword pwd --tlsuser user https://example.com
See also --tlsuser.
--tlsuser <name>
Set username for use with the TLS authentication method
specified with --tlsauthtype. Requires that --tlspassword also
is set.
This option does not work with TLS 1.3.
If --tlsuser is provided several times, the last set value is
used.
Example:
curl --tlspassword pwd --tlsuser user https://example.com
See also --tlspassword.
--tlsv1.0
(TLS) Forces curl to use TLS version 1.0 or later when
connecting to a remote TLS server.
In old versions of curl this option was documented to allow
_only_ TLS 1.0. That behavior was inconsistent depending on the
TLS library. Use --tls-max if you want to set a maximum TLS
version.
Providing --tlsv1.0 multiple times has no extra effect.
Example:
curl --tlsv1.0 https://example.com
See also --tlsv1.3.
--tlsv1.1
(TLS) Forces curl to use TLS version 1.1 or later when
connecting to a remote TLS server.
Example:
curl --tlsv1.1 https://example.com
See also --tlsv1.3 and --tls-max.
--tlsv1.2
(TLS) Forces curl to use TLS version 1.2 or later when
connecting to a remote TLS server.
In old versions of curl this option was documented to allow
_only_ TLS 1.2. That behavior was inconsistent depending on the
TLS library. Use --tls-max if you want to set a maximum TLS
version.
Providing --tlsv1.2 multiple times has no extra effect.
Example:
curl --tlsv1.2 https://example.com
See also --tlsv1.3 and --tls-max.
--tlsv1.3
(TLS) Forces curl to use TLS version 1.3 or later when
connecting to a remote TLS server.
If the connection is done without TLS, this option has no
effect. This includes QUIC-using (HTTP/3) transfers.
Note that TLS 1.3 is not supported by all TLS backends.
Providing --tlsv1.3 multiple times has no extra effect.
Example:
curl --tlsv1.3 https://example.com
See also --tlsv1.2 and --tls-max. Added in 7.52.0.
-1, --tlsv1
(TLS) Tells curl to use at least TLS version 1.x when
negotiating with a remote TLS server. That means TLS version 1.0
or higher
Providing -1, --tlsv1 multiple times has no extra effect.
Example:
curl --tlsv1 https://example.com
See also --http1.1 and --http2. -1, --tlsv1 requires that the
underlying libcurl was built to support TLS. This option is
mutually exclusive to --tlsv1.1 and --tlsv1.2 and --tlsv1.3.
--tr-encoding
(HTTP) Request a compressed Transfer-Encoding response using one
of the algorithms curl supports, and uncompress the data while
receiving it.
Providing --tr-encoding multiple times has no extra effect.
Disable it again with --no-tr-encoding.
including descriptive information, to the given output file. Use
"-" as filename to have the output sent to stdout.
This is similar to --trace, but leaves out the hex part and only
shows the ASCII part of the dump. It makes smaller output that
might be easier to read for untrained humans.
Note that verbose output of curl activities and network traffic
might contain sensitive data, including user names, credentials
or secret data content. Be aware and be careful when sharing
trace logs with others.
This option is global and does not need to be specified for each
use of --next.
If --trace-ascii is provided several times, the last set value
is used.
Example:
curl --trace-ascii log.txt https://example.com
See also -v, --verbose and --trace. This option is mutually
exclusive to --trace and -v, --verbose.
--trace-config <string>
Set configuration for trace output. A comma-separated list of
components where detailed output can be made available from.
Names are case-insensitive. Specify 'all' to enable all trace
components.
In addition to trace component names, specify "ids" and "time"
to avoid extra --trace-ids or --trace-time parameters.
See the curl_global_trace(3) man page for more details.
This option is global and does not need to be specified for each
use of --next.
--trace-config can be used several times in a command line
Example:
curl --trace-config ids,http/2 https://example.com
See also -v, --verbose and --trace. This option is mutually
exclusive to --trace and -v, --verbose. Added in 8.3.0.
--trace-ids
Prepends the transfer and connection identifiers to each trace
or verbose line that curl displays.
This option is global and does not need to be specified for each
use of --next.
Providing --trace-ids multiple times has no extra effect.
Disable it again with --no-trace-ids.
Example:
curl --trace-ids --trace-ascii output https://example.com
use of --next.
Providing --trace-time multiple times has no extra effect.
Disable it again with --no-trace-time.
Example:
curl --trace-time --trace-ascii output https://example.com
See also --trace and -v, --verbose.
--trace <file>
Enables a full trace dump of all incoming and outgoing data,
including descriptive information, to the given output file. Use
"-" as filename to have the output sent to stdout. Use "%" as
filename to have the output sent to stderr.
Note that verbose output of curl activities and network traffic
might contain sensitive data, including user names, credentials
or secret data content. Be aware and be careful when sharing
trace logs with others.
This option is global and does not need to be specified for each
use of --next.
If --trace is provided several times, the last set value is
used.
Example:
curl --trace log.txt https://example.com
See also --trace-ascii, --trace-config, --trace-ids and
--trace-time. This option is mutually exclusive to -v, --verbose
and --trace-ascii.
--unix-socket <path>
(HTTP) Connect through this Unix domain socket, instead of using
the network.
If --unix-socket is provided several times, the last set value
is used.
Example:
curl --unix-socket socket-path https://example.com
See also --abstract-unix-socket.
-T, --upload-file <file>
This transfers the specified local file to the remote URL.
If there is no file part in the specified URL, curl appends the
local file name to the end of the URL before the operation
starts. You must use a trailing slash (/) on the last directory
to prove to curl that there is no file name or curl thinks that
your last directory name is the remote file name to use.
When putting the local file name at the end of the URL, curl
ignores what is on the left side of any slash (/) or backslash
(\) used in the file name and only appends what is on the right
side of the rightmost such character.
If this option is used with a HTTP(S) URL, the PUT method is
used.
You can specify one -T, --upload-file for each URL on the
command line. Each -T, --upload-file + URL pair specifies what
to upload and to where. curl also supports "globbing" of the -T,
--upload-file argument, meaning that you can upload multiple
files to a single URL by using the same URL globbing style
supported in the URL.
When uploading to an SMTP server: the uploaded data is assumed
to be RFC 5322 formatted. It has to feature the necessary set of
headers and mail body formatted correctly by the user as curl
does not transcode nor encode it further in any way.
-T, --upload-file can be used several times in a command line
Examples:
curl -T file https://example.com
curl -T "img[1-1000].png" ftp://ftp.example.com/
curl --upload-file "{file1,file2}" https://example.com
See also -G, --get, -I, --head, -X, --request and -d, --data.
--url-query <data>
(all) This option adds a piece of data, usually a name + value
pair, to the end of the URL query part. The syntax is identical
to that used for --data-urlencode with one extension:
If the argument starts with a '+' (plus), the rest of the string
is provided as-is unencoded.
The query part of a URL is the one following the question mark
on the right end.
--url-query can be used several times in a command line
Examples:
curl --url-query name=val https://example.com
curl --url-query =encodethis http://example.net/foo
curl --url-query name@file https://example.com
curl --url-query @fileonly https://example.com
curl --url-query "+name=%20foo" https://example.com
See also --data-urlencode and -G, --get. Added in 7.87.0.
--url <url>
Specify a URL to fetch. This option is mostly handy when you
want to specify URL(s) in a config file.
If the given URL is missing a scheme name (such as "http://" or
"ftp://" etc) then curl makes a guess based on the host. If the
outermost subdomain name matches DICT, FTP, IMAP, LDAP, POP3 or
SMTP then that protocol is used, otherwise HTTP is used.
Guessing can be avoided by providing a full URL including the
scheme, or disabled by setting a default protocol (added in
7.45.0), see --proto-default for details.
To control where this URL is written, use the -o, --output or
Example:
curl --url https://example.com
See also -:, --next and -K, --config.
-B, --use-ascii
(FTP LDAP) Enable ASCII transfer. For FTP, this can also be
enforced by using a URL that ends with ";type=A". This option
causes data sent to stdout to be in text mode for win32 systems.
Providing -B, --use-ascii multiple times has no extra effect.
Disable it again with --no-use-ascii.
Example:
curl -B ftp://example.com/README
See also --crlf and --data-ascii.
-A, --user-agent <name>
(HTTP) Specify the User-Agent string to send to the HTTP server.
To encode blanks in the string, surround the string with single
quote marks. This header can also be set with the -H, --header
or the --proxy-header options.
If you give an empty argument to -A, --user-agent (""), it
removes the header completely from the request. If you prefer a
blank header, you can set it to a single space (" ").
If -A, --user-agent is provided several times, the last set
value is used.
Example:
curl -A "Agent 007" https://example.com
See also -H, --header and --proxy-header.
-u, --user <user:password>
Specify the user name and password to use for server
authentication. Overrides -n, --netrc and --netrc-optional.
If you simply specify the user name, curl prompts for a
password.
The user name and passwords are split up on the first colon,
which makes it impossible to use a colon in the user name with
this option. The password can, still.
On systems where it works, curl hides the given option argument
from process listings. This is not enough to protect credentials
from possibly getting seen by other users on the same system as
they still are visible for a brief moment before cleared. Such
sensitive data should be retrieved from a file instead or
similar and never used in clear text in a command line.
When using Kerberos V5 with a Windows based server you should
include the Windows domain name in the user name, in order for
the server to successfully obtain a Kerberos Ticket. If you do
not, then the initial authentication handshake may fail.
If you use a Windows SSPI-enabled curl binary and perform
Kerberos V5, Negotiate, NTLM or Digest authentication then you
can tell curl to select the user name and password from your
environment by specifying a single colon with this option: "-u
:".
If -u, --user is provided several times, the last set value is
used.
Example:
curl -u user:secret https://example.com
See also -n, --netrc and -K, --config.
--variable <[%]name=text/@file>
Set a variable with "name=content" or "name@file" (where "file"
can be stdin if set to a single dash (-)). The name is a case
sensitive identifier that must consist of no other letters than
a-z, A-Z, 0-9 or underscore. The specified content is then
associated with this identifier.
Setting the same variable name again overwrites the old contents
with the new.
The contents of a variable can be referenced in a later command
line option when that option name is prefixed with "--expand-",
and the name is used as "{{name}}" (without the quotes).
--variable can import environment variables into the name space.
Opt to either require the environment variable to be set or
provide a default value for the variable in case it is not
already set.
--variable %name imports the variable called 'name' but exits
with an error if that environment variable is not already set.
To provide a default value if the environment variable is not
set, use --variable %name=content or --variable %name@content.
Note that on some systems - but not all - environment variables
are case insensitive.
When expanding variables, curl supports a set of functions that
can make the variable contents more convenient to use. You apply
a function to a variable expansion by adding a colon and then
list the desired functions in a comma-separated list that is
evaluated in a left-to-right order. Variable content holding
null bytes that are not encoded when expanded, causes an error.
Available functions:
trim removes all leading and trailing white space.
json outputs the content using JSON string quoting
rules.
url shows the content URL (percent) encoded.
b64 expands the variable base64 encoded
-v, --verbose
Makes curl verbose during the operation. Useful for debugging
and seeing what's going on "under the hood". A line starting
with '>' means "header data" sent by curl, '<' means "header
data" received by curl that is hidden in normal cases, and a
line starting with '*' means additional info provided by curl.
If you only want HTTP headers in the output, -i, --include or
-D, --dump-header might be more suitable options.
If you think this option still does not give you enough details,
consider using --trace or --trace-ascii instead.
Note that verbose output of curl activities and network traffic
might contain sensitive data, including user names, credentials
or secret data content. Be aware and be careful when sharing
trace logs with others.
This option is global and does not need to be specified for each
use of --next.
Providing -v, --verbose multiple times has no extra effect.
Disable it again with --no-verbose.
Example:
curl --verbose https://example.com
See also -i, --include, -s, --silent, --trace and --trace-ascii.
This option is mutually exclusive to --trace and --trace-ascii.
-V, --version
Displays information about curl and the libcurl version it uses.
The first line includes the full version of curl, libcurl and
other 3rd party libraries linked with the executable.
The second line (starts with "Release-Date:") shows the release
date.
The third line (starts with "Protocols:") shows all protocols
that libcurl reports to support.
The fourth line (starts with "Features:") shows specific
features libcurl reports to offer. Available features include:
alt-svc
Support for the Alt-Svc: header is provided.
AsynchDNS
This curl uses asynchronous name resolves. Asynchronous
name resolves can be done using either the c-ares or the
threaded resolver backends.
brotli Support for automatic brotli compression over HTTP(S).
CharConv
curl was built with support for character set conversions
(like EBCDIC)
GSS-API
GSS-API is supported.
HSTS HSTS support is present.
HTTP2 HTTP/2 support has been built-in.
HTTP3 HTTP/3 support has been built-in.
HTTPS-proxy
This curl is built to support HTTPS proxy.
IDN This curl supports IDN - international domain names.
IPv6 You can use IPv6 with this.
Kerberos
Kerberos V5 authentication is supported.
Largefile
This curl supports transfers of large files, files larger
than 2GB.
libz Automatic decompression (via gzip, deflate) of compressed
files over HTTP is supported.
MultiSSL
This curl supports multiple TLS backends.
NTLM NTLM authentication is supported.
NTLM_WB
NTLM delegation to winbind helper is supported.
PSL PSL is short for Public Suffix List and means that this
curl has been built with knowledge about "public
suffixes".
SPNEGO SPNEGO authentication is supported.
SSL SSL versions of various protocols are supported, such as
HTTPS, FTPS, POP3S and so on.
SSPI SSPI is supported.
TLS-SRP
SRP (Secure Remote Password) authentication is supported
for TLS.
TrackMemory
Debug memory tracking is supported.
Unicode
Unicode support on Windows.
UnixSockets
Unix sockets support is provided.
See also -h, --help and -M, --manual.
-w, --write-out <format>
Make curl display information on stdout after a completed
transfer. The format is a string that may contain plain text
mixed with any number of variables. The format can be specified
as a literal "string", or you can have curl read the format from
a file with "@filename" and to tell curl to read the format from
stdin you write "@-".
The variables present in the output format are substituted by
the value or text that curl thinks fit, as described below. All
variables are specified as %{variable_name} and to output a
normal % you just write them as %%. You can output a newline by
using \n, a carriage return with \r and a tab space with \t.
The output is by default written to standard output, but can be
changed with %{stderr} and %output{}.
Output HTTP headers from the most recent request by using
%header{name} where name is the case insensitive name of the
header (without the trailing colon). The header contents are
exactly as sent over the network, with leading and trailing
whitespace trimmed (added in 7.84.0).
Select a specific target destination file to write the output
to, by using %output{name} (added in curl 8.3.0) where name is
the full file name. The output following that instruction is
then written to that file. More than one %output{} instruction
can be specified in the same write-out argument. If the file
name cannot be created, curl leaves the output destination to
the one used prior to the %output{} instruction. Use
%output{>>name} to append data to an existing file.
NOTE: In Windows the %-symbol is a special symbol used to expand
environment variables. In batch files all occurrences of % must
be doubled when using this option to properly escape. If this
option is used at the command prompt then the % cannot be
escaped and unintended expansion is possible.
The variables available are:
certs Output the certificate chain with details.
Supported only by the OpenSSL, GnuTLS, Schannel
and Secure Transport backends. (Added in 7.88.0)
content_type The Content-Type of the requested document, if
there was any.
errormsg The error message. (Added in 7.75.0)
exitcode The numerical exit code of the transfer. (Added
in 7.75.0)
filename_effective
The ultimate filename that curl writes out to.
This is only meaningful if curl is told to write
to a file with the -O, --remote-name or -o,
--output option. It's most useful in combination
arrays, since in the case of multiple headers
there can be multiple values. (Added in 7.83.0)
The header names provided in lowercase, listed in
order of appearance over the wire. Except for
duplicated headers. They are grouped on the first
occurrence of that header, each value is
presented in the JSON array.
http_code The numerical response code that was found in the
last retrieved HTTP(S) or FTP(s) transfer.
http_connect The numerical code that was found in the last
response (from a proxy) to a curl CONNECT
request.
http_version The http version that was effectively used.
(Added in 7.50.0)
json A JSON object with all available keys. (Added in
7.70.0)
local_ip The IP address of the local end of the most
recently done connection - can be either IPv4 or
IPv6.
local_port The local port number of the most recently done
connection.
method The http method used in the most recent HTTP
request. (Added in 7.72.0)
num_certs Number of server certificates received in the TLS
handshake. Supported only by the OpenSSL, GnuTLS,
Schannel and Secure Transport backends. (Added
in 7.88.0)
num_connects Number of new connects made in the recent
transfer.
num_headers The number of response headers in the most recent
request (restarted at each redirect). Note that
the status line IS NOT a header. (Added in
7.73.0)
num_redirects Number of redirects that were followed in the
request.
onerror The rest of the output is only shown if the
transfer returned a non-zero error. (Added in
7.75.0)
proxy_ssl_verify_result
The result of the HTTPS proxy's SSL peer
certificate verification that was requested. 0
means the verification was successful. (Added in
7.52.0)
redirect_url When an HTTP request was made without -L,
remote_ip The remote IP address of the most recently done
connection - can be either IPv4 or IPv6.
remote_port The remote port number of the most recently done
connection.
response_code The numerical response code that was found in the
last transfer (formerly known as "http_code").
scheme The URL scheme (sometimes called protocol) that
was effectively used. (Added in 7.52.0)
size_download The total amount of bytes that were downloaded.
This is the size of the body/data that was
transferred, excluding headers.
size_header The total amount of bytes of the downloaded
headers.
size_request The total amount of bytes that were sent in the
HTTP request.
size_upload The total amount of bytes that were uploaded.
This is the size of the body/data that was
transferred, excluding headers.
speed_download The average download speed that curl measured for
the complete download. Bytes per second.
speed_upload The average upload speed that curl measured for
the complete upload. Bytes per second.
ssl_verify_result
The result of the SSL peer certificate
verification that was requested. 0 means the
verification was successful.
stderr From this point on, the -w, --write-out output is
written to standard error. (Added in 7.63.0)
stdout From this point on, the -w, --write-out output is
written to standard output. This is the default,
but can be used to switch back after switching to
stderr. (Added in 7.63.0)
time_appconnect
The time, in seconds, it took from the start
until the SSL/SSH/etc connect/handshake to the
remote host was completed.
time_connect The time, in seconds, it took from the start
until the TCP connect to the remote host (or
proxy) was completed.
time_namelookup
The time, in seconds, it took from the start
until the name resolving was completed.
time_pretransfer
steps including name lookup, connect, pretransfer
and transfer before the final transaction was
started. time_redirect shows the complete
execution time for multiple redirections.
time_starttransfer
The time, in seconds, it took from the start
until the first byte is received. This includes
time_pretransfer and also the time the server
needed to calculate the result.
time_total The total time, in seconds, that the full
operation lasted.
url The URL that was fetched. (Added in 7.75.0)
url.scheme The scheme part of the URL that was fetched.
(Added in 8.1.0)
url.user The user part of the URL that was fetched. (Added
in 8.1.0)
url.password The password part of the URL that was fetched.
(Added in 8.1.0)
url.options The options part of the URL that was fetched.
(Added in 8.1.0)
url.host The host part of the URL that was fetched. (Added
in 8.1.0)
url.port The port number of the URL that was fetched. If
no port number was specified, but the URL scheme
is known, that scheme's default port number is
shown. (Added in 8.1.0)
url.path The path part of the URL that was fetched. (Added
in 8.1.0)
url.query The query part of the URL that was fetched.
(Added in 8.1.0)
url.fragment The fragment part of the URL that was fetched.
(Added in 8.1.0)
url.zoneid The zone id part of the URL that was fetched.
(Added in 8.1.0)
urle.scheme The scheme part of the effective (last) URL that
was fetched. (Added in 8.1.0)
urle.user The user part of the effective (last) URL that
was fetched. (Added in 8.1.0)
urle.password The password part of the effective (last) URL
that was fetched. (Added in 8.1.0)
urle.options The options part of the effective (last) URL that
was fetched. (Added in 8.1.0)
port number is shown. (Added in 8.1.0)
urle.path The path part of the effective (last) URL that
was fetched. (Added in 8.1.0)
urle.query The query part of the effective (last) URL that
was fetched. (Added in 8.1.0)
urle.fragment The fragment part of the effective (last) URL
that was fetched. (Added in 8.1.0)
urle.zoneid The zone id part of the effective (last) URL that
was fetched. (Added in 8.1.0)
urlnum The URL index number of this transfer, 0-indexed.
Unglobbed URLs share the same index number as the
origin globbed URL. (Added in 7.75.0)
url_effective The URL that was fetched last. This is most
meaningful if you have told curl to follow
location: headers.
If -w, --write-out is provided several times, the last set value
is used.
Example:
curl -w '%{response_code}\n' https://example.com
See also -v, --verbose and -I, --head.
--xattr
When saving output to a file, this option tells curl to store
certain file metadata in extended file attributes. Currently,
the URL is stored in the xdg.origin.url attribute and, for HTTP,
the content type is stored in the mime_type attribute. If the
file system does not support extended attributes, a warning is
issued.
Providing --xattr multiple times has no extra effect. Disable
it again with --no-xattr.
Example:
curl --xattr -o storage https://example.com
See also -R, --remote-time, -w, --write-out and -v, --verbose.
FILES
~/.curlrc
Default config file, see -K, --config for details.
ENVIRONMENT
The environment variables can be specified in lower case or upper case.
The lower case version has precedence. http_proxy is an exception as it
is only available in lower case.
Using an environment variable to set the proxy has the same effect as
using the -x, --proxy option.
[url-protocol]_PROXY [protocol://]<host>[:port]
Sets the proxy server to use for [url-protocol], where the
protocol is a protocol that curl supports and as specified in a
URL. FTP, FTPS, POP3, IMAP, SMTP, LDAP, etc.
ALL_PROXY [protocol://]<host>[:port]
Sets the proxy server to use if no protocol-specific proxy is
set.
NO_PROXY <comma-separated list of hosts/domains>
list of host names that should not go through any proxy. If set
to an asterisk '*' only, it matches all hosts. Each name in this
list is matched as either a domain name which contains the
hostname, or the hostname itself.
This environment variable disables use of the proxy even when
specified with the -x, --proxy option. That is
NO_PROXY=direct.example.com curl -x http://proxy.example.com
http://direct.example.com accesses the target URL directly, and
NO_PROXY=direct.example.com curl -x http://proxy.example.com
http://somewhere.example.com accesses the target URL through the
proxy.
The list of host names can also be include numerical IP
addresses, and IPv6 versions should then be given without
enclosing brackets.
IP addresses can be specified using CIDR notation: an appended
slash and number specifies the number of "network bits" out of
the address to use in the comparison (added in 7.86.0). For
example "192.168.0.0/16" would match all addresses starting with
"192.168".
APPDATA <dir>
On Windows, this variable is used when trying to find the home
directory. If the primary home variable are all unset.
COLUMNS <terminal width>
If set, the specified number of characters is used as the
terminal width when the alternative progress-bar is shown. If
not set, curl tries to figure it out using other ways.
CURL_CA_BUNDLE <file>
If set, it is used as the --cacert value.
CURL_HOME <dir>
If set, is the first variable curl checks when trying to find
its home directory. If not set, it continues to check
XDG_CONFIG_HOME
CURL_SSL_BACKEND <TLS backend>
If curl was built with support for "MultiSSL", meaning that it
has built-in support for more than one TLS backend, this
environment variable can be set to the case insensitive name of
the particular backend to use when curl is invoked. Setting a
name that is not a built-in alternative makes curl stay with the
default.
SSL backend names (case-insensitive): bearssl, gnutls, mbedtls,
QLOGDIR <directory name>
If curl was built with HTTP/3 support, setting this environment
variable to a local directory makes curl produce qlogs in that
directory, using file names named after the destination
connection id (in hex). Do note that these files can become
rather large. Works with the ngtcp2 and quiche QUIC backends.
SHELL Used on VMS when trying to detect if using a DCL or a unix
shell.
SSL_CERT_DIR <dir>
If set, it is used as the --capath value.
SSL_CERT_FILE <path>
If set, it is used as the --cacert value.
SSLKEYLOGFILE <file name>
If you set this environment variable to a file name, curl stores
TLS secrets from its connections in that file when invoked to
enable you to analyze the TLS traffic in real time using network
analyzing tools such as Wireshark. This works with the following
TLS backends: OpenSSL, libressl, BoringSSL, GnuTLS and wolfSSL.
USERPROFILE <dir>
On Windows, this variable is used when trying to find the home
directory. If the other, primary, variable are all unset. If
set, curl uses the path "$USERPROFILE\Application Data".
XDG_CONFIG_HOME <dir>
If CURL_HOME is not set, this variable is checked when looking
for a default .curlrc file.
PROXY PROTOCOL PREFIXES
The proxy string may be specified with a protocol:// prefix to specify
alternative proxy protocols.
If no protocol is specified in the proxy string or if the string does
not match a supported one, the proxy is treated as an HTTP proxy.
The supported proxy protocol prefixes are as follows:
http://
Makes it use it as an HTTP proxy. The default if no scheme
prefix is used.
https://
Makes it treated as an HTTPS proxy.
socks4://
Makes it the equivalent of --socks4
socks4a://
Makes it the equivalent of --socks4a
socks5://
Makes it the equivalent of --socks5
socks5h://
Makes it the equivalent of --socks5-hostname
instructions.
1 Unsupported protocol. This build of curl has no support for this
protocol.
2 Failed to initialize.
3 URL malformed. The syntax was not correct.
4 A feature or option that was needed to perform the desired
request was not enabled or was explicitly disabled at
build-time. To make curl able to do this, you probably need
another build of libcurl.
5 Could not resolve proxy. The given proxy host could not be
resolved.
6 Could not resolve host. The given remote host could not be
resolved.
7 Failed to connect to host.
8 Weird server reply. The server sent data curl could not parse.
9 FTP access denied. The server denied login or denied access to
the particular resource or directory you wanted to reach. Most
often you tried to change to a directory that does not exist on
the server.
10 FTP accept failed. While waiting for the server to connect back
when an active FTP session is used, an error code was sent over
the control connection or similar.
11 FTP weird PASS reply. Curl could not parse the reply sent to the
PASS request.
12 During an active FTP session while waiting for the server to
connect back to curl, the timeout expired.
13 FTP weird PASV reply, Curl could not parse the reply sent to the
PASV request.
14 FTP weird 227 format. Curl could not parse the 227-line the
server sent.
15 FTP cannot use host. Could not resolve the host IP we got in the
227-line.
16 HTTP/2 error. A problem was detected in the HTTP2 framing layer.
This is somewhat generic and can be one out of several problems,
see the error message for details.
17 FTP could not set binary. Could not change transfer method to
binary.
18 Partial file. Only a part of the file was transferred.
19 FTP could not download/access the given file, the RETR (or
similar) command failed.
23 Write error. Curl could not write data to a local filesystem or
similar.
25 Failed starting the upload. For FTP, the server typically denied
the STOR command.
26 Read error. Various reading problems.
27 Out of memory. A memory allocation request failed.
28 Operation timeout. The specified time-out period was reached
according to the conditions.
30 FTP PORT failed. The PORT command failed. Not all FTP servers
support the PORT command, try doing a transfer using PASV
instead!
31 FTP could not use REST. The REST command failed. This command is
used for resumed FTP transfers.
33 HTTP range error. The range "command" did not work.
34 HTTP post error. Internal post-request generation error.
35 SSL connect error. The SSL handshaking failed.
36 Bad download resume. Could not continue an earlier aborted
download.
37 FILE could not read file. Failed to open the file. Permissions?
38 LDAP cannot bind. LDAP bind operation failed.
39 LDAP search failed.
41 Function not found. A required LDAP function was not found.
42 Aborted by callback. An application told curl to abort the
operation.
43 Internal error. A function was called with a bad parameter.
45 Interface error. A specified outgoing interface could not be
used.
47 Too many redirects. When following redirects, curl hit the
maximum amount.
48 Unknown option specified to libcurl. This indicates that you
passed a weird option to curl that was passed on to libcurl and
rejected. Read up in the manual!
49 Malformed telnet option.
52 The server did not reply anything, which here is considered an
error.
53 SSL crypto engine not found.
59 Could not use specified SSL cipher.
60 Peer certificate cannot be authenticated with known CA
certificates.
61 Unrecognized transfer encoding.
63 Maximum file size exceeded.
64 Requested FTP SSL level failed.
65 Sending the data requires a rewind that failed.
66 Failed to initialize SSL Engine.
67 The user name, password, or similar was not accepted and curl
failed to log in.
68 File not found on TFTP server.
69 Permission problem on TFTP server.
70 Out of disk space on TFTP server.
71 Illegal TFTP operation.
72 Unknown TFTP transfer ID.
73 File already exists (TFTP).
74 No such user (TFTP).
77 Problem reading the SSL CA cert (path? access rights?).
78 The resource referenced in the URL does not exist.
79 An unspecified error occurred during the SSH session.
80 Failed to shut down the SSL connection.
82 Could not load CRL file, missing or wrong format.
83 Issuer check failed.
84 The FTP PRET command failed.
85 Mismatch of RTSP CSeq numbers.
86 Mismatch of RTSP Session Identifiers.
87 Unable to parse FTP file list.
88 FTP chunk callback reported error.
89 No connection available, the session is queued.
90 SSL public key does not matched pinned public key.
95 A problem was detected in the HTTP/3 layer. This is somewhat
generic and can be one out of several problems, see the error
message for details.
96 QUIC connection error. This error may be caused by an SSL
library error. QUIC is the protocol used for HTTP/3 transfers.
97 Proxy handshake error.
98 A client-side certificate is required to complete the TLS
handshake.
99 Poll or select returned fatal error.
XX More error codes might appear here in future releases. The
existing ones are meant to never change.
BUGS
If you experience any problems with curl, submit an issue in the
project's bug tracker on GitHub: https://github.com/curl/curl/issues
AUTHORS / CONTRIBUTORS
Daniel Stenberg is the main author, but the whole list of contributors
is found in the separate THANKS file.
WWW
https://curl.se
SEE ALSO
ftp(1), wget(1)
curl 8.5.0 December 05 2023 curl(1)