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PASSWD(1) NetBSD General Commands Manual PASSWD(1)
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by Kimmo Suominen.
Based on man-cgi by Panagiotis Christias.
passwd -- modify a user's password
passwd [-d files | -l] [user]
passwd [-d nis | -y] [user]
passwd [-d krb5 | -k] [principal]
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
All options may not be available on all systems.
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 pass-
word, passwd uses pwd_mkdb(8) to update the password data-
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
-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)
The type of cipher used to encrypt the password depends on the configura-
tion in passwd.conf(5). It can be different for local and NIS passwords.
/etc/master.passwd The user database
/etc/passwd A Version 7 format password file
/etc/passwd.XXXXXX Temporary copy of the password file
chpass(1), login(1), pwhash(1), passwd(5), passwd.conf(5), pam(8),
Robert Morris and Ken Thompson, UNIX password security.
A passwd command appeared in Version 6 AT&T UNIX.
NetBSD 8.0 February 25, 2005 NetBSD 8.0