These functions are designed as conveniences for interactive programs which update the passwd file and do nothing else. They generally handle errors by printing out a message to the standard error stream and possibly aborting the process.
The
pw_init() function prepares for a passwd update by unlimiting all resource constraints, disabling core dumps (thus preventing dumping the contents of the passwd database into a world-readable file), and disabling most signals.
The
pw_edit() function runs an editor (named by the environment variable EDITOR, or
/usr/bin/vi if EDITOR is not set) on the file
filename (or
/etc/ptmp if
filename is
NULL). If
notsetuid is nonzero,
pw_edit() will set the effective user and group ID to the real user and group ID before running the editor.
The
pw_prompt() function asks the user whether he or she wants to re-edit the password file; if the answer is no,
pw_prompt() deletes the lock file and exits the process.
The
pw_copy() function reads a passwd file from
ffd and writes it to
tfd, updating the entry corresponding to pw->pw_name with the information in
pw. If
old_pw is not
NULL, it checks to make sure the old entry is the same as the one described in
old_pw or the process is aborted. If an entry is not found to match
pw, a new entry is appended to the passwd file only if the real user ID is 0. If an error occurs,
pw_copy() will display a message on
stderr and call
pw_error().
The
pw_copyx() function performs the same operation as
pw_copy() with the exception of error handling. Upon an error,
pw_copyx() will write an error message into the buffer pointed to by
errbuf which has the size
errbufsz.
The
pw_scan() function accepts in
bp a passwd entry as it would be represented in
/etc/master.passwd and fills in
pw with corresponding values; string fields in
pw will be pointers into
bp. Some characters in
bp will be overwritten with 0s in order to terminate the strings pointed to by
pw. If
flags is non-null, it should be cleared and the following options enabled if required:
_PASSWORD_NOWARN
Don't print warnings.
_PASSWORD_OLDFMT
Parse bp as an old format entry as found in /etc/passwd.
Upon return it is cleared, and filled in with the following flags:
_PASSWORD_NOUID
The uid field of bp is empty.
_PASSWORD_NOGID
The gid field of bp is empty.
_PASSWORD_NOCHG
The change field of bp is empty.
_PASSWORD_NOEXP
The expire field of bp is empty.
The
pw_error() function displays an error message, aborts the current passwd update, and exits the current process. If
err is non-zero, a warning message beginning with
name is printed for the current value of
errno. The process exits with status
eval.