passwd



PASSWD(1)                   General Commands Manual                  PASSWD(1)


NAME

     passwd - modify a user's password


SYNOPSIS

     passwd [user]


DESCRIPTION

     passwd changes the user's password.  If no user is specified, the user's
     login name is used (see logname(1)).  First, the user is prompted for
     their current password.  If the current password is correctly typed, a
     new password is requested.  The new password must be entered twice to
     avoid typing errors.

     The new password should be at least six characters long and not purely
     alphabetic.  Its total length must be less than _PASSWORD_LEN (currently
     128 characters).  A mixture of both lower and uppercase letters, numbers,
     and meta-characters is encouraged.

     The quality of the password can be enforced by specifying an external
     checking program via the ``passwordcheck'' variable in login.conf(5).

     The superuser is not required to provide a user's current password if
     only the local password is modified.

     Password encryption parameters depend on the configuration of the
     ``localcipher'' capability in login.conf(5).  If none is specified, then
     blowfish with 8 rounds is used.


FILES

     /etc/login.conf     configuration options
     /etc/master.passwd  user database
     /etc/passwd         user database, with confidential information removed
     /etc/passwd.XXXXXX  temporary copy of the password file
     /etc/ptmp           lock file for the passwd database


DIAGNOSTICS

     Attempting to lock password file, please wait or press ^C to abort

     The password file is currently locked by another process; passwd will
     keep trying to lock the password file until it succeeds or you hit the
     interrupt character (control-C by default).  If passwd is interrupted
     while trying to gain the lock the password change will be lost.

     If the process holding the lock was prematurely terminated the lock file
     may be stale and passwd will wait forever trying to lock the password
     file.  To determine whether a live process is actually holding the lock,
     the admin may run the following:

           $ fstat /etc/ptmp

     If no process is listed, it is safe to remove the /etc/ptmp file to clear
     the error.


SEE ALSO

     chpass(1), encrypt(1), logname(1), login.conf(5), passwd(5), pwd_mkdb(8),
     vipw(8)

     Robert Morris and Ken Thompson, "Password security: a case history",
     Communications of the ACM, Issue 11, Volume 22, 594-597, Nov. 1979.


HISTORY

     A passwd command appeared in Version 3 AT&T UNIX.

OpenBSD 5.9                    November 26, 2015                   OpenBSD 5.9

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