NAME

passwd − change login password

SYNOPSIS

passwd [ name ]

DESCRIPTION

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

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

New passwords must be at least four characters long if they use a sufficiently rich alphabet and at least six characters long if monocase.  These rules are relaxed if you are insistent enough. 

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

FILES

/etc/passwd

SEE ALSO

login(1), passwd(5), crypt(3)
Robert Morris and Ken Thompson, Password Security: A Case History

7th Edition