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 avoid error. 

New passwords must be at least four characters long if they use a sufficiently extensive alphabet and at least six characters long if monocase.  (These rules are flexible and can be by passed by persistent entry of a desired password.) 

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 /etc/ptmp

SEE ALSO

login(1), passwd(5), 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(3) would probably be suitable.

4th Berkeley Distribution  —  %W%%Q%%Y%