1.\" Copyright (c) 1989, 1991, 1993 2.\" The Regents of the University of California. All rights reserved. 3.\" 4.\" Redistribution and use in source and binary forms, with or without 5.\" modification, are permitted provided that the following conditions 6.\" are met: 7.\" 1. Redistributions of source code must retain the above copyright 8.\" notice, this list of conditions and the following disclaimer. 9.\" 2. Redistributions in binary form must reproduce the above copyright 10.\" notice, this list of conditions and the following disclaimer in the 11.\" documentation and/or other materials provided with the distribution. 12.\" 3. Neither the name of the University nor the names of its contributors 13.\" may be used to endorse or promote products derived from this software 14.\" without specific prior written permission. 15.\" 16.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 17.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 18.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 19.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 20.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 21.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 22.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 23.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 24.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 25.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 26.\" SUCH DAMAGE. 27.\" 28.\" @(#)pwcache.3 8.1 (Berkeley) 6/9/93 29.\" $FreeBSD: src/lib/libc/gen/pwcache.3,v 1.15 2007/01/09 00:27:55 imp Exp $ 30.\" $DragonFly: src/lib/libc/gen/pwcache.3,v 1.2 2003/06/17 04:26:42 dillon Exp $ 31.\" 32.Dd March 22, 2002 33.Dt PWCACHE 3 34.Os 35.Sh NAME 36.Nm pwcache 37.Nd cache password and group entries 38.Sh LIBRARY 39.Lb libc 40.Sh SYNOPSIS 41.In pwd.h 42.Ft const char * 43.Fn user_from_uid "uid_t uid" "int nouser" 44.In grp.h 45.Ft const char * 46.Fn group_from_gid "gid_t gid" "int nogroup" 47.Sh DESCRIPTION 48The 49.Fn user_from_uid 50function returns the user name associated with the argument 51.Fa uid . 52The user name is cached so that multiple calls with the same 53.Fa uid 54do not require additional calls to 55.Xr getpwuid 3 . 56If there is no user associated with the 57.Fa uid , 58a pointer is returned 59to a string representation of the 60.Fa uid , 61unless the argument 62.Fa nouser 63is non-zero, in which case a 64.Dv NULL 65pointer is returned. 66.Pp 67The 68.Fn group_from_gid 69function returns the group name associated with the argument 70.Fa gid . 71The group name is cached so that multiple calls with the same 72.Fa gid 73do not require additional calls to 74.Xr getgrgid 3 . 75If there is no group associated with the 76.Fa gid , 77a pointer is returned 78to a string representation of the 79.Fa gid , 80unless the argument 81.Fa nogroup 82is non-zero, in which case a 83.Dv NULL 84pointer is returned. 85.Sh SEE ALSO 86.Xr getgrgid 3 , 87.Xr getpwuid 3 88.Sh HISTORY 89The 90.Fn user_from_uid 91and 92.Fn group_from_gid 93functions first appeared in 94.Bx 4.4 . 95