PW_LOCK(3)                OpenBSD Programmer's Manual               PW_LOCK(3)

NAME
     pw_lock, pw_mkdb, pw_abort - passwd file update functions



SYNOPSIS
     #include <util.h>

     int
     pw_lock(int retries);

     int
     pw_mkdb();

     void
     pw_abort();

DESCRIPTION
     The pw_lock(), pw_mkdb(), and pw_abort() functions allow a program to up-
     date the system passwd database.

     The pw_lock() function attempts to lock the passwd database by creating
     the file /etc/ptmp with an exclusive lock (using flock(2) semantics) and
     returns the file descriptor of that file.  If retries is greater than ze-
     ro, pw_lock() will try multiple times to open /etc/ptmp, waiting one sec-
     ond between tries.  In addition to being a lock file, /etc/ptmp will also
     hold the contents of the new passwd file.

     The pw_mkdb() function updates the passwd file from the contents of
     /etc/ptmp. You should finish writing to and close the file descriptor re-
     turned by pw_lock() before calling pw_mkdb().  If pw_mkdb() fails and you
     do not wish to retry, you should make sure to call pw_abort() to clean up
     the lock file.

     The pw_abort() function aborts a passwd file update by deleting
     /etc/ptmp. The passwd database remains unchanged.

RETURN VALUES
     The pw_lock() and pw_mkdb() functions return -1 if they are unable to
     complete properly.

FILES
     /etc/master.passwd
     /etc/ptmp

SEE ALSO
     flock(2),  pw_init(3)

OpenBSD 2.6                    December 15, 1995                             1