.TH PASSWD 1 .UC .SH NAME passwd \- change login password .SH SYNOPSIS .B passwd [ name ] .SH DESCRIPTION This command changes (or installs) a password associated with the user .IR name (your own name by default). .PP 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. .PP 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. .PP A user may change his own password. Group masters may change the passwords of members of their group. The super-user may change any user's password. .SH FILES /etc/passwd .SH "SEE ALSO" login(1), crypt(3), passwd(5) .br Robert Morris and Ken Thompson, .I Password Security: A Case History