NAME
passwd —
modify a user's
password
SYNOPSIS
passwd |
[-d files |
-l]
[user] |
passwd |
[-d nis |
-y]
[user] |
passwd |
[-d krb5 |
-k]
[principal] |
DESCRIPTION
passwd changes the user's password. First, the user is
prompted for their current password. If the current password is correctly
typed, a new password is requested. The new password must be entered twice to
avoid typing errors.
The new password should be at least six characters long and not purely
alphabetic. Its total length must be less than
_PASSWORD_LEN
(currently 128 characters). Numbers,
upper case letters and meta characters are encouraged.
All options may not be available on all systems.
-
-
- -d
database
- This option specifies the password database that should be
updated. The following databases are supported:
-
-
- files
- This specifies that the password change should be
applied to the local password file. When changing only the local
password, passwd uses
pwd_mkdb(8) to update
the password databases.
-
-
- nis
- This specifies that the password change should be
applied to the NIS password database. The
rpc.yppasswdd(8)
daemon should be running on the master NIS server.
-
-
- krb5
- This specifies that the user's Kerberos 5 password
should be changed. The host must be configured to use Kerberos. See
krb5.conf(5).
-
-
- -l
- This is the equivalent of -d
files.
-
-
- -y
- This is the equivalent of -d
nis.
-
-
- -k
- This is the equivalent of -d
krb5.
If a password database is not specified,
passwd will change
the password database as determined by the Pluggable Authentication Module
(PAM) library.
The type of cipher used to encrypt the password depends on the configuration in
passwd.conf(5). It can be
different for local and NIS passwords.
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),
login(1),
pwhash(1),
passwd(5),
passwd.conf(5),
pam(8),
pwd_mkdb(8),
vipw(8)
Robert Morris and
Ken Thompson, UNIX password
security.
HISTORY
A
passwd command appeared in
Version 6
AT&T UNIX.