xref: /freebsd/share/man/man9/dnv.9 (revision fa9896e082a1046ff4fbc75fcba4d18d1f2efc19)

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.Dd July 26, 2016
.Dt DNV 9
.Os
.Sh NAME
.Nm dnvlist_get ,
.Nm dnvlist_take
.Nd "API for getting name/value pairs. Nonexistent pairs do not raise an error."
.Sh LIBRARY
.Lb libnv
.Sh SYNOPSIS
.In sys/dnv.h
.Ft bool
.Fn dnvlist_get_bool "const nvlist_t *nvl" "const char *name" "bool defval"
.Ft uint64_t
.Fn dnvlist_get_number "const nvlist_t *nvl" "const char *name" "uint64_t defval"
.Ft char *
.Fn dnvlist_get_string "const nvlist_t *nvl" "const char *name" "const char *defval"
.Ft nvlist_t *
.Fn dnvlist_get_nvlist "const nvlist_t *nvl" "const char *name" "nvlist_t *defval"
.Ft int
.Fn dnvlist_get_descriptor "const nvlist_t *nvl" "const char *name" "int defval"
.Ft void *
.Fn dnvlist_get_binary "const nvlist_t *nvl" "const char *name" "size_t *sizep" "void *defval" "size_t defsize"
.Ft bool
.Fn dnvlist_take_bool "const nvlist_t *nvl" "const char *name" "bool defval"
.Ft uint64_t
.Fn dnvlist_take_number "const nvlist_t *nvl" "const char *name" "uint64_t defval"
.Ft char *
.Fn dnvlist_take_string "const nvlist_t *nvl" "const char *name" "const char *defval"
.Ft nvlist_t *
.Fn dnvlist_take_nvlist "const nvlist_t *nvl" "const char *name" "nvlist_t *defval"
.Ft int
.Fn dnvlist_take_descriptor "const nvlist_t *nvl" "const char *name" "int defval"
.Ft void *
.Fn dnvlist_take_binary "const nvlist_t *nvl" "const char *name" "size_t *sizep" "void *defval" "size_t defsize"
.Sh DESCRIPTION
The
.Nm libnv
library permits easy management of name/value pairs and can send and receive
them over sockets.
For more information, also see
.Xr nv 9 .
.Pp
The
.Nm dnvlist_get
family of functions returns the value associated with the specified name.
If an element of the specified name does not exist, the function returns the
value provided in
.Fa defval .
Returned strings, 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.
.Pp
The
.Nm 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
.Nm defval
is returned.
When the value is a string, binary, or array value, the caller is
responsible for freeing returned memory with
.Fn free 3 .
When the value is an nvlist, the caller is responsible for destroying the
returned nvlist with
.Fn nvlist_destroy .
When the value is a descriptor, the caller is responsible for closing the
returned descriptor with
.Fn close 2 .
.Sh SEE ALSO
.Xr close 2 ,
.Xr free 3 ,
.Xr nv 9
.Sh HISTORY
The
.Nm dnv
API appeared in
.Fx 11.0 .
.Sh AUTHORS
.An -nosplit
The
.Nm dnv
API was implemented by
.An Pawel Jakub Dawidek Aq Mt pawel@dawidek.net
under sponsorship from the FreeBSD Foundation.
This manual page was written by
.An Adam Starak Aq Mt starak.adam@gmail.com