OpenBSD-4.6/lib/libutil/pw_lock.3

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.\"	$OpenBSD: pw_lock.3,v 1.15 2007/11/19 22:07:37 jmc 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 $Mdocdate: November 19 2007 $
.Dt PW_LOCK 3
.Os
.Sh NAME
.Nm pw_lock ,
.Nm pw_mkdb ,
.Nm pw_abort
.Nd passwd file update functions
.Sh SYNOPSIS
.Fd #include <util.h>
.Ft int
.Fn pw_lock "int retries"
.Ft int
.Fn pw_mkdb "char *username" "int pwflags"
.Ft void
.Fn pw_abort
.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.
A different lock file can be specified with
.Xr pw_file 3 .
.Pp
.Xr pw_init 3
must be called before
.Fn pw_lock .
.Pp
The
.Fn pw_mkdb
function updates the passwd file from the contents of
.Pa /etc/ptmp
via
.Xr pwd_mkdb 8 .
If a
.Fa username
is specified, only the record for the specified user will be updated.
The
.Fa pwflags
are specified by
.Tn OR Ns 'ing
the following values:
.Pp
.Bl -tag -width _PASSWORD_SECUREONLY -offset "xxxx" -compact
.It Dv _PASSWORD_SECUREONLY
only update the secure database file
.Pq Pa /etc/spwd.db .
.It Dv _PASSWORD_OMITV7
do not update the Version 7 format password file
.Pq Pa /etc/passwd .
.El
.Pp
By default the secure, insecure and Version 7 format password databases
are updated.
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
function returns \-1 on error and sets
.Va errno .
The
.Fn pw_mkdb
function returns \-1 if it is unable to complete properly.
.Sh FILES
.Bl -tag -width "/etc/master.passwdXXX" -compact
.It Pa /etc/master.passwd
Current password file.
.It Pa /etc/passwd
A Version 7 format password file.
.It Pa /etc/ptmp
Password lock file.
.It Pa /etc/pwd.db
Insecure password database file.
.It Pa /etc/spwd.db
Secure password database file.
.El
.Sh ERRORS
.Bl -tag -width Er
.It Bq Er EINVAL
.Fn pw_lock
was called before
.Xr pw_init 3 .
.El
.Pp
.Fn pw_lock
may also fail and set
.Va errno
for any of the errors specified for the routine
.Xr open 2 .
.Sh SEE ALSO
.Xr flock 2 ,
.Xr pw_file 3 ,
.Xr pw_init 3 ,
.Xr pwd_mkdb 8