DNV(9) FreeBSD Kernel Developer's Manual DNV(9)
NAME
dnvlist_get, dnvlist_take - API for getting name/value pairs with a
default value
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
The libnv library permits easy management of name/value pairs and can
send and receive them over sockets. For more information, see nv(9).
The dnvlist_get functions return the value associated with name. If an
element named name does not exist, the function returns the value
provided in defval. Returned strings, nvlists, descriptors, binaries, or
arrays must not be modified by the user since 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 functions return the value associated with name and
removes the associated element from nvl. If an element named 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 <
[email protected]>
under sponsorship from the FreeBSD Foundation. This manual page was
written by Adam Starak <
[email protected]>
FreeBSD 14.1-RELEASE-p8 January 3, 2025 FreeBSD 14.1-RELEASE-p8