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SETMODE(3) FreeBSD Library Functions Manual SETMODE(3)
NAME
getmode, setmode - modify mode bits
LIBRARY
Standard C Library (libc, -lc)
SYNOPSIS
#include <unistd.h>
mode_t
getmode(const void *set, mode_t mode);
void *
setmode(const char *mode_str);
DESCRIPTION
The getmode() function returns a copy of the file permission bits mode as
altered by the values pointed to by set. While only the mode bits are
altered, other parts of the file mode may be examined.
The setmode() function takes an absolute (octal) or symbolic value, as
described in chmod(1), as an argument and returns a pointer to mode
values to be supplied to getmode(). Because some of the symbolic values
are relative to the file creation mask, setmode() may call umask(2). If
this occurs, the file creation mask will be restored before setmode()
returns. If the calling program changes the value of its file creation
mask after calling setmode(), setmode() must be called again if getmode()
is to modify future file modes correctly.
If the mode passed to setmode() is invalid or if memory cannot be
allocated for the return value, setmode() returns NULL.
The value returned from setmode() is obtained from malloc() and should be
returned to the system with free() when the program is done with it,
generally after a call to getmode().
ERRORS
The setmode() function may fail and set errno for any of the errors
specified for the library routine malloc(3) or strtol(3). In addition,
setmode() will fail and set errno to:
[EINVAL] The mode argument does not represent a valid mode.
SEE ALSO
chmod(1), stat(2), umask(2), malloc(3)
HISTORY
The getmode() and setmode() functions first appeared in 4.4BSD.
BUGS
The setmode() function is not thread safe. Files created in other
threads while setmode() is being called may be created with a umask of 0.
FreeBSD 14.0-RELEASE-p11 July 18, 2019 FreeBSD 14.0-RELEASE-p11