PWD_MKDB(8)                 System Manager's Manual                PWD_MKDB(8)

NAME
     pwd_mkdb – generate the password databases

SYNOPSIS
     pwd_mkdb [-ciN] [-p | -s] [-d directory] [-S cachesize] [-u username]
              file

DESCRIPTION
     The pwd_mkdb utility serves no purpose in macOS and is included solely
     for backward compatibility.  The -c and -p flags, and options which
     modify the behavior of those flags, still work.  The -s flag has no
     effect.

     See DirectoryService(8) for information on identity management in macOS.

LEGACY DESCRIPTION
     The pwd_mkdb utility creates db(3) style secure and insecure databases
     for the specified 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.

     -d directoryO
           Store databases into specified destination directory instead of
           /etc.

     -i    Ignore locking failure of the master.passwd file.  This option is
           intended to be used to build password files in the release process
           over NFS where no contention can happen.  A non-default directory
           must also be specified with the -d option for locking to be
           ignored.  Other use of this option is strongly discouraged.

     -N    Tell pwd_mkdb to exit with an error if it cannot obtain a lock on
           the file.  By default, we block waiting for a lock on the source
           file.  The lock is held through the rebuilding of the database.

     -p    Create a Version 7 style password file and install it into
           /etc/passwd.  Cannot be used in conjunction with the -s flag.

     -S cachesize
           Specify in megabytes the size of the memory cache used by the
           hashing library.  On systems with a large user base, a small cache
           size can lead to prohibitively long database file rebuild times.
           As a rough guide, the memory usage of pwd_mkdb in megabytes will be
           a little bit more than twice the figure specified here.  The
           default is 2 megabytes.

     -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 password
           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.

     -u username
           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.

     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)).

     The pwd_mkdb utility exits zero on success, non-zero on failure.

ENVIRONMENT
     If the PW_SCAN_BIG_IDS environment variable is set, pwd_mkdb will
     suppress the warning messages that are normally generated for large user
     and group IDs.  Such IDs can cause serious problems with software that
     makes assumptions about the values of IDs.

FILES
     /etc/pwd.db                       The insecure password database file.
     /etc/pwd.db.tmp                   A temporary file.
     /etc/spwd.db                      The secure password database file.
     /etc/spwd.db.tmp                  A temporary file.
     /etc/master.passwd                The current password file.
     /etc/passwd                       A Version 7 format password file.

EXAMPLES
     Regenerate the password database after manually editing or replacing the
     password file:

            /usr/sbin/pwd_mkdb -p /etc/master.passwd

COMPATIBILITY
     Previous versions of the system had a program similar to pwd_mkdb,
     mkpasswd(8), 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.

SEE ALSO
     chpass(1), passwd(1), db(3), getpwent(3), passwd(5), vipw(8)

BUGS
     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
     different 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
     this problem.

macOS 15.2                     December 20, 2023                    macOS 15.2