generate the password
pwd_mkdb creates a pair of Berkeley
databases for the specified file. These databases are then installed into
/etc/pwd.db, respectively. The
file argument is installed into
/etc/master.passwd by renaming
file. The file must be in the
correct format (see
passwd(5)). It is important to note that the format used in this
system is different from the historic 6th Edition-style format.
The options are as follows:
- Check if the password file is in the correct format. Do not change, add, or remove any files.
- Operate in a base directory other than the default of /etc. All absolute paths (including file) will be made relative to directory. Any directories specified as a part of file will be stripped off. This option is used to create password databases in directories other than /etc; for instance in a chroot(8) jail.
- Create a 6th Edition-style password file and install it into /etc/passwd.
- Only update the secure version of the database. This is most commonly used
in conjunction with the
-uflag during a password change. Because the insecure database doesn't contain the password there is no reason to update it if the only change is in the password field. Cannot be used in conjunction with the
- Only update the record for the specified user. Utilities that operate on a single user can use this option to avoid the overhead of rebuilding the entire database. This option must never be used if the line number of the user's record in /etc/master.passwd has changed.
- The absolute path to a file in master.passwd format, as described in passwd(5).
The two databases differ in that the secure version contains the user's encrypted password and the insecure version has an asterisk (‘*’).
The databases are used by the C library password routines (see getpwent(3)).
pwd_mkdb exits zero on success, non-zero
- current password file
- a 6th Edition-style password file
- insecure password database file
- temporary file
- secure password database file
- temporary file
chpass(1), passwd(1), dbopen(3), getpwent(3), passwd(5), vipw(8)
Previous versions of the system had a program similar to
which built dbm(3) style databases for the password file but depended on the
calling programs to install them. The program was renamed in order that
previous users of the program not be surprised by the changes in
Because of the necessity for atomic update of the password files,
rename(2) to install them. This, however, requires that the file
specified on the command line live on the same file system as the
There are the obvious races with multiple people running
pwd_mkdb on different password files at the same
time. The front-ends to
vipw(8) handle the locking necessary to avoid this problem.