PASSWD(1) PASSWD(1)
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 insis-
tent 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