UNIX - change login password

`passwd` - change login password and password attributes.

Usage:
passwd [OPTION...]

OPTION:
-k, --keep-tokens keep non-expired authentication tokens
-d, --delete delete the password for the named account (root only)
-l, --lock lock the named account (root only)
-u, --unlock unlock the named account (root only)
-f, --force force operation

-x, --maximum=DAYS maximum password lifetime (root only)
-n, --minimum=DAYS minimum password lifetime (root only)
-w, --warning=DAYS number of days warning users receives before
password expiration (root only)
-i, --inactive=DAYS number of days after password expiration when an
account becomes disabled (root only)
-S, --status report password status on the named account (root
only)
--stdin read new tokens from stdin (root only)


EXAMPLE:

[root@server root]# passwd smith
Changing password for user smith.
New password:
Retype new password:
passwd: all authentication tokens updated successfully.

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