usr/src/usr.bin/passwd/passwd.1

.\" Copyright (c) 1990 The Regents of the University of California.
.\" All rights reserved.
.\"
.\" %sccs.include.redist.man%
.\"
.\"     @(#)passwd.1    6.6 (Berkeley) %G%
.\"
.Dd
.Dt PASSWD 1
.Os BSD 4
.Sh NAME
.Nm passwd
.Nd modify password file information
.Sh SYNOPSIS
.Nm passwd
.Op Ar user
.Sh DESCRIPTION
.Nm Passwd
changes the user's password.  First, the user is prompted for their
current
password, and, if that is correct typed, for a new password.  The new
password must be entered two times to verify any typing errors.  The
super-user is not prompted for the old password.
.Pp
The new password must be at least six characters long and cannot be
purely alphabetic.  Numbers, upper case letters and meta characters
are encouraged.
.Pp
Once the password has been verified,
.Nm passwd
uses
.Xr mkpasswd  8
to update the user database.  This is run in the background, and,
at very large sites could take several minutes.  Until this update
is completed, the password file is unavailable for other updates
and the new password will not be available to programs.
.Sh FILES
.Dw /etc/master.passwd
.Di L
.Dp Pa /etc/master.passwd
the user database
.Dp
.Sh SEE ALSO
.Xr chpass 1 ,
.Xr login 1 ,
.Xr passwd 5 ,
.Xr mkpasswd 8 ,
.Xr vipw 8
.br
Robert Morris and Ken Thompson,
.Em UNIX password security
.Sh HISTORY
A
.Nm passwd
command appeared in Version 6 AT&T UNIX.