generate the password
pwd_mkdb creates a pair of Berkeley
databases from file and installs them into
/etc/pwd.db. The file argument
is renamed to /etc/master.passwd.
The options are as follows:
- Check whether 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.
- Also create a legacy 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(5) format.
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)).
- current password file
- legacy password file
- insecure password database file
- temporary file
- secure password database file
- temporary file
pwd_mkdb utility exits 0 on
success, and >0 if an error occurs.
chpass(1), passwd(1), dbopen(3), getpwent(3), passwd(5), vipw(8)
pwd_mkdb utility first appeared 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.