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DNV(9) FreeBSD Kernel Developer's Manual DNV(9)
NAME
dnvlist_get, dnvlist_take - API for getting name/value pairs. Nonexistent
pairs do not raise an error.
LIBRARY
Name/value pairs library (libnv, -lnv)
SYNOPSIS
#include <sys/dnv.h>
bool
dnvlist_get_bool(const nvlist_t *nvl, const char *name, bool defval);
uint64_t
dnvlist_get_number(const nvlist_t *nvl, const char *name,
uint64_t defval);
char *
dnvlist_get_string(const nvlist_t *nvl, const char *name,
const char *defval);
nvlist_t *
dnvlist_get_nvlist(const nvlist_t *nvl, const char *name,
nvlist_t *defval);
int
dnvlist_get_descriptor(const nvlist_t *nvl, const char *name,
int defval);
void *
dnvlist_get_binary(const nvlist_t *nvl, const char *name, size_t *sizep,
void *defval, size_t defsize);
bool
dnvlist_take_bool(const nvlist_t *nvl, const char *name, bool defval);
uint64_t
dnvlist_take_number(const nvlist_t *nvl, const char *name,
uint64_t defval);
char *
dnvlist_take_string(const nvlist_t *nvl, const char *name,
const char *defval);
nvlist_t *
dnvlist_take_nvlist(const nvlist_t *nvl, const char *name,
nvlist_t *defval);
int
dnvlist_take_descriptor(const nvlist_t *nvl, const char *name,
int defval);
void *
dnvlist_take_binary(const nvlist_t *nvl, const char *name, size_t *sizep,
void *defval, size_t defsize);
DESCRIPTION
nvlists, descriptors, binaries, or arrays must not be modified by the
user. They still belong to the nvlist. If the nvlist is in an error
state, attempts to use any of these functions will cause the program to
abort.
The dnvlist_take family of functions returns the value associated with
the specified name and removes the element from the nvlist. If an
element of the supplied name does not exist, the value provided in defval
is returned. When the value is a string, binary, or array value, the
caller is responsible for freeing returned memory with free(3). When the
value is an nvlist, the caller is responsible for destroying the returned
nvlist with nvlist_destroy(). When the value is a descriptor, the caller
is responsible for closing the returned descriptor with close(2).
SEE ALSO
close(2), free(3), nv(9)
HISTORY
The dnv API appeared in FreeBSD 11.0.
AUTHORS
The dnv API was implemented by Pawel Jakub Dawidek <pawel@dawidek.net>
under sponsorship from the FreeBSD Foundation. This manual page was
written by Adam Starak <starak.adam@gmail.com>
FreeBSD 14.0-RELEASE-p6 July 26, 2016 FreeBSD 14.0-RELEASE-p6