.\" Copyright (c) 1989, 1991, 1993 .\" The Regents of the University of California. All rights reserved. .\" .\" Redistribution and use in source and binary forms, with or without .\" modification, are permitted provided that the following conditions .\" are met: .\" 1. Redistributions of source code must retain the above copyright .\" notice, this list of conditions and the following disclaimer. .\" 2. Redistributions in binary form must reproduce the above copyright .\" notice, this list of conditions and the following disclaimer in the .\" documentation and/or other materials provided with the distribution. .\" 3. All advertising materials mentioning features or use of this software .\" must display the following acknowledgement: .\" This product includes software developed by the University of .\" California, Berkeley and its contributors. .\" 4. Neither the name of the University nor the names of its contributors .\" may be used to endorse or promote products derived from this software .\" without specific prior written permission. .\" .\" THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND .\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE .\" ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE .\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL .\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS .\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT .\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY .\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF .\" SUCH DAMAGE. .\" .\" @(#)pwcache.3 8.1 (Berkeley) 6/9/93 .\" $FreeBSD: src/lib/libc/gen/pwcache.3,v 1.10 2001/10/01 16:08:51 ru Exp $ .\" .Dd June 9, 1993 .Dt PWCACHE 3 .Os .Sh NAME .Nm pwcache .Nd cache password and group entries .Sh LIBRARY .Lb libc .Sh SYNOPSIS .In pwd.h .Ft char * .Fn user_from_uid "uid_t uid" "int nouser" .In grp.h .Ft char * .Fn group_from_gid "gid_t gid" "int nogroup" .Sh DESCRIPTION The .Fn user_from_uid function returns the user name associated with the argument .Fa uid . The user name is cached so that multiple calls with the same .Fa uid do not require additional calls to .Xr getpwuid 3 . If there is no user associated with the .Fa uid , a pointer is returned to a string representation of the .Fa uid , unless the argument .Fa nouser is non-zero, in which case a .Dv NULL pointer is returned. .Pp The .Fn group_from_gid function returns the group name associated with the argument .Fa gid . The group name is cached so that multiple calls with the same .Fa gid do not require additional calls to .Xr getgrgid 3 . If there is no group associated with the .Fa gid , a pointer is returned to a string representation of the .Fa gid , unless the argument .Fa nogroup is non-zero, in which case a .Dv NULL pointer is returned. .Sh SEE ALSO .Xr getgrgid 3 , .Xr getpwuid 3 .Sh HISTORY The .Fn user_from_uid and .Fn group_from_gid functions first appeared in .Bx 4.4 .