Content-type: text/html Man page of lckpwdf

lckpwdf

Section: Standard C Library Functions (3C)
Updated: 29 Dec 1996
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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 TYPEATTRIBUTE VALUE
MT-LevelMT-Safe

 

SEE ALSO

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


 

Index

NAME
SYNOPSIS
DESCRIPTION
RETURN VALUES
USAGE
FILES
ATTRIBUTES
SEE ALSO

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Time: 02:37:20 GMT, October 02, 2010