PW_LOCK(3) BSD Programmer's Manual PW_LOCK(3)
pw_lock, pw_mkdb, pw_abort - passwd file update functions
#include <util.h> int pw_lock(int retries); int pw_mkdb(char *username, int pwflags); void pw_abort();
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 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 via pwd_mkdb(8). If a username is specified, only the record for the specified user will be updated. The pwflags are specified by OR'ing the following values: _PASSWORD_SECUREONLY only update the secure database file (/etc/spwd.db). _PASSWORD_OMITV7 do not update the Version 7 format password file (/etc/passwd). By default the secure, insecure and Version 7 format password databases are updated. 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. The pw_abort() function aborts a passwd file update by deleting /etc/ptmp. The passwd database remains unchanged.
The pw_lock() and pw_mkdb() functions return -1 if they are unable to complete properly.
/etc/master.passwd current password file /etc/ptmp password lock file /etc/passwd a Version 7 format password file /etc/pwd.db insecure password database file /etc/spwd.db secure password database file
flock(2), pw_init(3), pwd_mkdb(8) MirOS BSD #10-current August 20, 2001 1
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