xref: /titanic_52/usr/src/man/man3c/lckpwdf.3c (revision 174bc6499d233e329ecd3d98a880a7b07df16bfa)
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Copyright (c) 1997, Sun Microsystems, Inc. All Rights Reserved
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When distributing Covered Code, include this CDDL HEADER in each file and include the License file at usr/src/OPENSOLARIS.LICENSE. If applicable, add the following below this CDDL HEADER, with the fields enclosed by brackets "[]" replaced with your own identifying information: Portions Copyright [yyyy] [name of copyright owner]
LCKPWDF 3C "Dec 29, 1996"
NAME
lckpwdf, ulckpwdf - manipulate shadow password database lock file
SYNOPSIS

#include <shadow.h>

int lckpwdf(void);

int ulckpwdf(void);
DESCRIPTION

The lckpwdf() and ulckpwdf() functions enable modification access to the password databases through the lock file. A process first uses lckpwdf() to lock the lock file, thereby gaining exclusive rights to modify the /etc/passwd or /etc/shadow password database. See passwd(4) and shadow(4). Upon completing modifications, a process should release the lock on the lock file using ulckpwdf(). This mechanism prevents simultaneous modification of the password databases. The lock file, /etc/.pwd.lock, is used to coordinate modification access to the password databases /etc/passwd and /etc/shadow.

RETURN VALUES

If lckpwdf() is successful in locking the file within 15 seconds, it returns 0. If unsuccessful (for example, /etc/.pwd.lock is already locked), it returns -1.

If ulckpwdf() is successful in unlocking the file /etc/.pwd.lock, it returns 0. If unsuccessful (for example, /etc/.pwd.lock is already unlocked), it returns -1.

USAGE

These routines are for internal use only; compatibility is not guaranteed.

FILES
/etc/passwd

password database

/etc/shadow

shadow password database

/etc/.pwd.lock

lock file

ATTRIBUTES

See attributes(5) for descriptions of the following attributes:

ATTRIBUTE TYPE ATTRIBUTE VALUE
MT-Level MT-Safe
SEE ALSO

getpwnam(3C), getspnam(3C), passwd(4), shadow(4), attributes(5)