Current File : //usr/share/man/man3c/lckpwdf.3c

'\" te
.\"  Copyright (c) 1997, Sun Microsystems, Inc. All Rights Reserved
.TH lckpwdf 3C "29 Dec 1996" "SunOS 5.11" "Standard C Library Functions"
.SH NAME
lckpwdf, ulckpwdf \- manipulate shadow password database lock file 
.SH SYNOPSIS
.LP
.nf
#include <shadow.h>

\fBint\fR \fBlckpwdf\fR(\fBvoid\fR);
.fi

.LP
.nf
\fBint\fR \fBulckpwdf\fR(\fBvoid\fR);
.fi

.SH DESCRIPTION
.sp
.LP
The \fBlckpwdf()\fR and \fBulckpwdf()\fR functions enable modification access to the password databases through the lock file. A process first uses \fBlckpwdf()\fR to lock the lock file, thereby gaining exclusive rights to modify the  \fB/etc/passwd\fR or  \fB/etc/shadow\fR password database.  See \fBpasswd\fR(4) and \fBshadow\fR(4). Upon completing modifications, a process should release the lock on the lock file using \fBulckpwdf()\fR. This mechanism prevents simultaneous modification of the password databases. The lock file, \fB/etc/.pwd.lock\fR, is used to coordinate modification access to the password databases \fB/etc/passwd\fR and  \fB/etc/shadow\fR.
.SH RETURN VALUES
.sp
.LP
If \fBlckpwdf()\fR is successful in locking the file within 15 seconds, it returns \fB0\fR. If unsuccessful (for example,  \fB/etc/.pwd.lock\fR is already locked), it returns \fB\(mi1\fR\&.
.sp
.LP
If \fBulckpwdf()\fR is successful in unlocking the file  \fB/etc/.pwd.lock\fR, it returns \fB0\fR. If unsuccessful (for example,  \fB/etc/.pwd.lock\fR is already unlocked), it returns \fB\(mi1\fR\&.
.SH USAGE
.sp
.LP
These routines are for internal use only; compatibility is not guaranteed.
.SH FILES
.sp
.ne 2
.mk
.na
\fB\fB/etc/passwd\fR\fR
.ad
.RS 18n
.rt  
password database
.RE

.sp
.ne 2
.mk
.na
\fB\fB/etc/shadow\fR\fR
.ad
.RS 18n
.rt  
shadow password database
.RE

.sp
.ne 2
.mk
.na
\fB\fB/etc/.pwd.lock\fR\fR
.ad
.RS 18n
.rt  
lock file
.RE

.SH ATTRIBUTES
.sp
.LP
See \fBattributes\fR(5) for descriptions of the following attributes:
.sp

.sp
.TS
tab() box;
cw(2.75i) |cw(2.75i) 
lw(2.75i) |lw(2.75i) 
.
ATTRIBUTE TYPEATTRIBUTE VALUE
_
MT-LevelMT-Safe
.TE

.SH SEE ALSO
.sp
.LP
\fBgetpwnam\fR(3C), \fBgetspnam\fR(3C), \fBpasswd\fR(4), \fBshadow\fR(4), \fBattributes\fR(5)