1.\" 2.\" Copyright (c) 2016 Adam Starak <starak.adam@gmail.com> 3.\" All rights reserved. 4.\" 5.\" Redistribution and use in source and binary forms, with or without 6.\" modification, are permitted provided that the following conditions 7.\" are met: 8.\" 1. Redistributions of source code must retain the above copyright 9.\" notice, this list of conditions and the following disclaimer. 10.\" 2. Redistributions in binary form must reproduce the above copyright 11.\" notice, this list of conditions and the following disclaimer in the 12.\" documentation and/or other materials provided with the distribution. 13.\" 14.\" THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND 15.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 16.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 17.\" ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE 18.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 19.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 20.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 21.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 22.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 23.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 24.\" SUCH DAMAGE. 25.\" 26.\" $FreeBSD$ 27.\" 28.Dd June 18, 2018 29.Dt CNV 9 30.Os 31.Sh NAME 32.Nm cnvlist_get , 33.Nm cnvlist_take , 34.Nm cnvlist_free 35.Nd "API for managing name/value pairs by cookie." 36.Sh LIBRARY 37.Lb libnv 38.Sh SYNOPSIS 39.In sys/cnv.h 40.Ft const char * 41.Fn cnvlist_name "const void *cookie" 42.Ft int 43.Fn cnvlist_type "const void *cookie" 44.\" 45.Ft bool 46.Fn cnvlist_get_bool "const void *cookie" 47.Ft uint64_t 48.Fn cnvlist_get_number "const void *cookie" 49.Ft "const char *" 50.Fn cnvlist_get_string "const void *cookie" 51.Ft "const nvlist_t *" 52.Fn cnvlist_get_nvlist "const void *cookie" 53.Ft "const void *" 54.Fn cnvlist_get_binary "const void *cookie" "size_t *sizep" 55.Ft "const bool *" 56.Fn cnvlist_get_bool_array "const void *cookie" "size_t *nitemsp" 57.Ft "const uint64_t *" 58.Fn cnvlist_get_number_array "const void *cookie" "size_t *nitemsp" 59.Ft "const char * const *" 60.Fn cnvlist_get_string_array "const void *cookie" "size_t *nitemsp" 61.Ft "const nvlist_t * const *" 62.Fn cnvlist_get_nvlist_array "const void *cookie" "size_t *nitemsp" 63.Ft int 64.Fn cnvlist_get_descriptor "const void *cookie" 65.Ft "const int *" 66.Fn cnvlist_get_descriptor_array "const void *cookie" "size_t *nitemsp" 67.\" 68.Ft bool 69.Fn cnvlist_take_bool "void *cookie" 70.Ft uint64_t 71.Fn cnvlist_take_number "void *cookie" 72.Ft "const char *" 73.Fn cnvlist_take_string "void *cookie" 74.Ft "const nvlist_t *" 75.Fn cnvlist_take_nvlist "void *cookie" 76.Ft "const void *" 77.Fn cnvlist_take_binary "void *cookie" "size_t *sizep" 78.Ft "const bool *" 79.Fn cnvlist_take_bool_array "void *cookie" "size_t *nitemsp" 80.Ft "const uint64_t *" 81.Fn cnvlist_take_number_array "void *cookie" "size_t *nitemsp" 82.Ft "const char * const *" 83.Fn cnvlist_take_string_array "void *cookie" "size_t *nitemsp" 84.Ft "const nvlist_t * const *" 85.Fn cnvlist_take_nvlist_array "void *cookie" "size_t *nitemsp" 86.Ft int 87.Fn cnvlist_take_descriptor "void *cookie" 88.Ft "const int *" 89.Fn cnvlist_take_descriptor_array "void *cookie" "size_t *nitemsp" 90.\" 91.Ft void 92.Fn cnvlist_free_null "void *cookie" 93.Ft void 94.Fn cnvlist_free_bool "void *cookie" 95.Ft void 96.Fn cnvlist_free_number "void *cookie" 97.Ft void 98.Fn cnvlist_free_string "void *cookie" 99.Ft void 100.Fn cnvlist_free_nvlist "void *cookie" 101.Ft void 102.Fn cnvlist_free_descriptor "void *cookie" 103.Ft void 104.Fn cnvlist_free_binary "void *cookie" 105.Ft void 106.Fn cnvlist_free_bool_array "void *cookie" 107.Ft void 108.Fn cnvlist_free_number_array "void *cookie" 109.Ft void 110.Fn cnvlist_free_string_array "void *cookie" 111.Ft void 112.Fn cnvlist_free_nvlist_array "void *cookie" 113.Ft void 114.Fn cnvlist_free_descriptor_array "void *cookie" 115.Sh DESCRIPTION 116The 117.Nm libnv 118library permits easy management of name/value pairs and can send and receive 119them over sockets. 120For more information, also see 121.Xr nv 9 . 122.Pp 123The concept of cookies is explained in 124.Fn nvlist_next , 125.Fn nvlist_get_parent , 126and 127.Fn nvlist_get_pararr 128from 129.Xr nv 9 . 130.Pp 131The 132.Fn cnvlist_name 133function returns the name of an element associated with the given cookie. 134.Pp 135The 136.Fn cnvlist_type 137function returns the type of an element associated with the given cookie. 138Types which can be returned are described in 139.Xr nv 9 . 140.Pp 141The 142.Nm cnvlist_get 143family of functions obtains the value associated with the given cookie. 144Returned strings, nvlists, descriptors, binaries, or arrays must not be modified 145by the user, since they still belong to the nvlist. 146The nvlist must not be in an error state. 147.Pp 148The 149.Nm cnvlist_take 150family of functions returns the value associated with the given cookie and 151removes the element from the nvlist. 152When the value is a string, binary, or array value, the caller is responsible 153for freeing the returned memory with 154.Fn free 3 . 155When the value is an nvlist, the caller is responsible for destroying the 156returned nvlist with 157.Fn nvlist_destroy . 158When the value is a descriptor, the caller is responsible for closing the 159returned descriptor with the 160.Fn close 2 . 161.Pp 162The 163.Nm cnvlist_free 164family of functions removes an element of the supplied cookie and frees all 165resources. 166If an element of the given cookie has the wrong type or does not exist, the 167program 168is aborted. 169.Sh EXAMPLE 170The following example demonstrates how to deal with cnvlist API. 171.Bd -literal 172int type; 173void *cookie, *scookie, *bcookie; 174nvlist_t *nvl; 175char *name; 176 177nvl = nvlist_create(0); 178nvlist_add_bool(nvl, "test", 1 == 2); 179nvlist_add_string(nvl, "test2", "cnvlist"); 180cookie = NULL; 181 182while (nvlist_next(nvl, &type, &cookie) != NULL) { 183 switch (type) { 184 case NV_TYPE_BOOL: 185 printf("test: %d\\n", cnvlist_get_bool(cookie)); 186 bcookie = cookie; 187 break; 188 case NV_TYPE_STRING: 189 printf("test2: %s\\n", cnvlist_get_string(cookie)); 190 scookie = cookie; 191 break; 192 } 193} 194 195name = cnvlist_take_string(scookie); 196cnvlist_free_bool(bcookie); 197 198printf("test2: %s\\n", name); 199free(name); 200 201printf("nvlist_empty = %d\\n", nvlist_empty(nvl)); 202nvlist_destroy(nvl); 203 204return (0); 205.Ed 206.Sh SEE ALSO 207.Xr close 2 , 208.Xr free 3 , 209.Xr nv 9 210.Sh AUTHORS 211The 212.Nm cnv 213API was created during the Google Summer Of Code 2016 by 214.An Adam Starak . 215