HP-UX Reference (11i v2 07/12) - 3 Library Functions A-M (vol 6)

l
lckpwdf(3C) lckpwdf(3C)
NAME
lckpwdf(), ulckpwdf() - control access to the /etc/passwd and /etc/shadow files
SYNOPSIS
#include <shadow.h>
int lckpwdf (void)
int ulckpwdf (void)
DESCRIPTION
The lckpwdf() and ulckpwdf() routines are used to coordinate modification access to the password
file /etc/passwd and to the shadow password file
/etc/shadow . The lock file used by these two rou-
tines is
/etc/.pwd.lock
. A process first calls lckpwdf() to gain exclusive access rights for
modification. When modifications are complete,
ulckpwdf() is called to release the lock on
/etc/.pwd.lock
. This mechanism prevents simultaneous modification of the files.
RETURN VALUE
The
lckpwdf() routine returns zero upon successful completion. If the lock could not be obtained, it
returns −1 and sets errno to indicate the error.
The ulckpwdf() routine returns zero upon successful completion. If the lock has already been released,
ulckpwdf() returns −1 and sets errno to indicate the error.
FILES
/etc/passwd
/etc/shadow
/etc/.pwd.lock
SEE ALSO
getpwent(3C), passwd(4), thread_safety(5).
HP-UX 11i Version 2: December 2007 Update − 1 − Hewlett-Packard Company 683