NAME

lckpwdf, ulckpwdf − manipulate shadow password database lock file

SYNOPSIS

#include <shadow.h>

int lckpwdf(void);

int ulckpwdf(void);

DESCRIPTION

lckpwdf() and ulckpwdf() are routines that are used to gain 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.  Upon completing modifications, a process should release the lock on the lock file using ulckpwdf().  This mechanism prevents simultaneous modification of the password databases.  /etc/.pwd.lock is the lock file.  It is used to coordinate modification access to the password databases /etc/passwd and /etc/shadow. 

lckpwdf() attempts to lock the file /etc/.pwd.lock within 15 seconds.  If unsuccessful, for example, /etc/.pwd.lock is already locked, it returns −1.  If successful, a return code other than −1 is returned. 

ulckpwdf() attempts to unlock the file /etc/.pwd.lock.  If unsuccessful, for example, /etc/.pwd.lock is already unlocked, it returns −1.  If successful, it returns 0. 

RETURN VALUES

lckpwdf() and ulckpwdf() return −1 on failure, and 0 otherwise. 

FILES

/etc/shadow

/etc/passwd

/etc/.pwd.lock

ATTRIBUTES

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

SEE ALSO

getpwnam(3C), getspnam(3C), attributes(5)

NOTES

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

SunOS 5.6  —  Last change: 29 Dec 1996