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. All advertising materials mentioning features or use of this software 13.\" must display the following acknowledgement: 14.\" This product includes software developed by the University of 15.\" California, Berkeley and its contributors. 16.\" 4. Neither the name of the University nor the names of its contributors 17.\" may be used to endorse or promote products derived from this software 18.\" without specific prior written permission. 19.\" 20.\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 21.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 22.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 23.\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 24.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 25.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 26.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 27.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 28.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 29.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 30.\" SUCH DAMAGE. 31.\" 32.\" @(#)pwcache.3 8.1 (Berkeley) 6/9/93 33.\" $FreeBSD: src/lib/libc/gen/pwcache.3,v 1.6.2.4 2001/12/14 18:33:51 ru Exp $ 34.\" $DragonFly: src/lib/libc/gen/pwcache.3,v 1.2 2003/06/17 04:26:42 dillon Exp $ 35.\" 36.Dd June 9, 1993 37.Dt PWCACHE 3 38.Os 39.Sh NAME 40.Nm pwcache 41.Nd cache password and group entries 42.Sh LIBRARY 43.Lb libc 44.Sh SYNOPSIS 45.In stdlib.h 46.Ft char * 47.Fn user_from_uid "unsigned long uid" "int nouser" 48.Ft char * 49.Fn group_from_gid "unsigned long gid" "int nogroup" 50.Sh DESCRIPTION 51The 52.Fn user_from_uid 53function returns the user name associated with the argument 54.Fa uid . 55The user name is cached so that multiple calls with the same 56.Fa uid 57do not require additional calls to 58.Xr getpwuid 3 . 59If there is no user associated with the 60.Fa uid , 61a pointer is returned 62to a string representation of the 63.Fa uid , 64unless the argument 65.Fa nouser 66is non-zero, in which case a 67.Dv NULL 68pointer is returned. 69.Pp 70The 71.Fn group_from_gid 72function returns the group name associated with the argument 73.Fa gid . 74The group name is cached so that multiple calls with the same 75.Fa gid 76do not require additional calls to 77.Xr getgrgid 3 . 78If there is no group associated with the 79.Fa gid , 80a pointer is returned 81to a string representation of the 82.Fa gid , 83unless the argument 84.Fa nogroup 85is non-zero, in which case a 86.Dv NULL 87pointer is returned. 88.Sh SEE ALSO 89.Xr getgrgid 3 , 90.Xr getpwuid 3 91.Sh HISTORY 92The 93.Fn user_from_uid 94and 95.Fn group_from_gid 96functions first appeared in 97.Bx 4.4 . 98