PW_LOCK(3) BSD Library Functions Manual PW_LOCK(3)
pw_lock, pw_mkdb, pw_abort, pw_setprefix, pw_getprefix -- passwd file update functions
System Utilities Library (libutil, -lutil)
pw_mkdb(const char *username, int secureonly);
pw_setprefix(const char *new_prefix);
const char *
The pw_lock(), pw_mkdb(), and pw_abort() functions allow a program to update the system
The pw_lock() function attempts to lock the passwd database by creating the file /etc/ptmp,
and returns the file descriptor of that file. If retries is greater than zero, pw_lock()
will try multiple times to open /etc/ptmp, waiting one second 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 returned 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. If the username argument is not NULL, only database
entries pertaining to the specified user will be modified. If the secureonly argument is
non-zero, only the secure database will be updated.
The pw_abort() function aborts a passwd file update by deleting /etc/ptmp. The passwd data-
base remains unchanged.
The pw_setprefix() function defines the root directory used for passwd file updates. If the
prefix is set to /newroot pw_lock() will operate on /newroot/etc/ptmp afterwards. The
default prefix is an empty string.
The pw_getprefix() function returns the root directory which is currently used for passwd
The pw_lock() and pw_mkdb() functions return -1 if they are unable to complete properly.
BSD February 17, 2007 BSD