NAME

passwd − change login password

SYNTAX

passwd [ user ] [ −g ]

DESCRIPTION

The passwd command changes your login password listed in the /etc/passwd file.  If name is not specified, uses your current login name. 

The −g option causes passwd to change or install the appropriate password for group name in the /etc/group file. 

The passwd 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. 

If user is specified, passwd changes the password for that user.  If the −g option is specified, passwd changes the group password listed in the /etc/group file. 

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

RESTRICTIONS

The −g option is restricted to use by the superuser only. 

FILES

/etc/passwd

SEE ALSO

login(1), newgrp(1), crypt(3), passwd(5)
“Password Security: A Case History”