PWD_MKDB(8) BSD System Manager's Manual PWD_MKDB(8)
pwd_mkdb -- generate the password databases
pwd_mkdb [-c] [-p | -s] [-d directory] [-u username] file
pwd_mkdb creates db(3) style secure and insecure databases for the speci-
fied file. These databases are then installed into /etc/spwd.db and
/etc/pwd.db, respectively. The file is installed into
/etc/master.passwd. 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 Version 7 style format.
The options are as follows:
-c Check if the password file is in the correct format. Do not
change, add, or remove any files.
-p Create a Version 7 style password file and install it into
-s Only update the secure version of the database. This is most
commonly used in conjunction with the -u flag during a password
change. Because the insecure database doesn't contain the pass-
word there is no reason to update it if the only change is in the
password field. Cannot be used in conjunction with the -p flag.
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.
Only update the record for the specified user. Utilities that
operate on a single user can use this option to avoid the over-
head 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.
file The absolute path to a file in master.passwd format, as described
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
pwd_mkdb exits zero on success, non-zero on failure.
/etc/master.passwd current password file
/etc/passwd a Version 7 format password file
/etc/pwd.db insecure password database file
/etc/pwd.db.tmp temporary file
/etc/spwd.db secure password database file
/etc/spwd.db.tmp temporary file
chpass(1), passwd(1), db(3), getpwent(3), passwd(5), vipw(8)
Previous versions of the system had a program similar to pwd_mkdb,
mkpasswd, 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 functionality.
Because of the necessity for atomic update of the password files,
pwd_mkdb uses rename(2) to install them. This, however, requires that
the file specified on the command line live on the same file system as
the /etc directory.
There are the obvious races with multiple people running pwd_mkdb on dif-
ferent password files at the same time. The front-ends to pwd_mkdb,
chpass(1), passwd(1), and vipw(8) handle the locking necessary to avoid
BSD June 6, 1993 BSD