NAME

passwd − change login password

SYNOPSIS

passwd [ −f filename ] [ username ]

DESCRIPTION

This command changes (or installs) a password associated with the user username (your own by default). 

passwd prompts for the old password and then for the new one.  You must supply both, and the new password must be typed twice to forestall mistakes. 

New passwords should be at least five characters long, if they combine upper and lower-case characters, or at least six characters long if in monocase.  Users that persist in entering shorter passwords are compromising their own security. 

Only the owner of the name or the super-user may change a password; the owner must prove he knows the old password. 

Use yppasswd to change your passwd in the network Yellow Pages.  This will not affect your local password, or your password on any remote machines on which you have accounts. 

OPTIONS

−fTreat filename as the password file. 

FILES

/etc/passwd
/etc/yp/passwd

SEE ALSO

login(1), passwd(5), yppasswd(1), crypt(3)
Robert Morris and Ken Thompson, UNIX password security

BUGS

The password file information should be kept in a different data structure allowing indexed access; dbm(3X) would probably be suitable.

passwd will change a local passwd, but not a passwd in the network Yellow Pages.  Refer to yppasswd(1) for information on how to change a Yellow Pages passwd.

4BSD