NAME
passwd
—
modify a user's password
SYNOPSIS
passwd |
[-i infosystem
[-l location]]
[-u authname]
[user] |
DESCRIPTION
The passwd
utility changes the user's
password. If the user is not the super-user, passwd
first prompts for the current password and will not continue unless the
correct password is entered.
When entering the new password, the characters entered do not
echo, in order to avoid the password being seen by a passer-by. The
passwd
utility prompts for the new password twice in
order to detect typing errors.
The new password should be at least six characters long and not
purely alphabetic. Its total length should be less than
_PASSWORD_LEN
(currently 128 characters), although
some directory systems allow longer passwords. Numbers, upper case letters,
and meta characters are encouraged.
Once the password has been verified,
passwd
communicates the new password to the
directory system.
-i
infosystem- This option specifies where the password update should be applied. Under
Mac OS X 10.5 and later, supported directory systems are:
- PAM
- (default) Pluggable Authentication Modules.
- opendirectory
- A system conforming to Open Directory APIs and supporting updates (including LDAP, etc). If no -l option is specified, the search node is used.
- file
- The local flat-files (included for legacy configurations).
- nis
- A remote NIS server containing the user's password.
-l
location- This option causes the password to be updated in the given location of the
chosen directory system.
- for file,
- location may be a file name (/etc/master.passwd is the default)
- for nis,
- location may be a NIS domainname
- for opendirectory,
- location may be a directory node name
- for PAM,
- location is not used
-u
authname- This option specifies the user name to use when authenticating to the directory node.
- user
- This optional argument specifies the user account whose password will be changed. This account's current password may be required, even when run as the super-user, depending on the directory system.
FILES
- /etc/master.passwd
- The user database
- /etc/passwd
- A Version 7 format password file
- /etc/passwd.XXXXXX
- Temporary copy of the password file
SEE ALSO
chpass(1), dscl(1), login(1), passwd(5), pwd_mkdb(8), vipw(8)
Robert Morris and Ken Thompson, UNIX password security.
HISTORY
A passwd
command appeared in
Version 6 AT&T UNIX.