NetBSD/lib/libutil/pw_lock.3

.\"	$NetBSD: pw_lock.3,v 1.5 2000/07/10 11:19:16 ad Exp $
.\"
.\" Copyright (c) 1995
.\"	The Regents of the University of California.  All rights reserved.
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.\" This code is derived from software developed by the Computer Systems
.\" Engineering group at Lawrence Berkeley Laboratory under DARPA contract
.\" BG 91-66 and contributed to Berkeley.
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.Dd December 15, 1995
.Dt PW_LOCK 3
.Os
.Sh NAME
.Nm pw_lock ,
.Nm pw_mkdb ,
.Nm pw_abort
.Nd passwd file update functions
.Sh LIBRARY
.Lb libutil
.Sh SYNOPSIS
.Fd #include <util.h>
.Ft int
.Fn pw_lock "int retries"
.Ft int
.Fn pw_mkdb "void"
.Ft void
.Fn pw_abort "void"
.Sh DESCRIPTION
The
.Fn pw_lock ,
.Fn pw_mkdb ,
and
.Fn pw_abort
functions allow a program to update the system passwd database.
.Pp
The
.Fn pw_lock
function attempts to lock the passwd database by creating the file
.Pa /etc/ptmp ,
and returns the file descriptor of that file.  If
.Fa retries
is greater than zero,
.Fn pw_lock
will try multiple times to open
.Pa /etc/ptmp ,
waiting one second between tries.  In addition to being a lock file,
.Pa /etc/ptmp
will also hold the contents of the new passwd file.
.Pp
The
.Fn pw_mkdb
function updates the passwd file from the contents of
.Pa /etc/ptmp .
You should finish writing to and close the file descriptor returned by
.Fn pw_lock
before calling
.Fn pw_mkdb .
If
.Fn pw_mkdb
fails and you do not wish to retry, you should make sure to call
.Fn pw_abort
to clean up the lock file.
.Pp
The
.Fn pw_abort
function aborts a passwd file update by deleting
.Pa /etc/ptmp .
The passwd database remains unchanged.
.Sh RETURN VALUES
The
.Fn pw_lock
and
.Fn pw_mkdb
functions return -1 if they are unable to complete properly.
.Sh FILES
.Bl -tag -width /etc/master.passwd -compact
.It Pa /etc/master.passwd
.It Pa /etc/ptmp
.El
.Sh SEE ALSO
.Xr pw_init 3