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pwd_mkdb(8)

NAME

     pwd_mkdb -- generate the password databases

SYNOPSIS

     pwd_mkdb [-C] [-N] [-p] [-i] [-d directory] [-s cachesize] [-u username]
	      file

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.

     -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.

     -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.

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

     -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.

     -s cachesize
	   Specify in megabytes the size of the memory cache used by the hash-
	   ing 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.

     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.
     /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.

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 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
     this problem.

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)

FreeBSD 5.4			 June 6, 1993			   FreeBSD 5.4

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