passwd - update a user’s authentication tokens(s)
[SYNOPSIS] passwd OPTION USER
option
-d This is a quick way to disable a password for an account
# passwd -d user
-l This option is used to lock the specified account and it is available to root only
# passwd -l user
-u This is the reverse of the -l option - it will unlock the account password by removing the ! prefix
# passwd -u user
-x This will set the maximum password lifetime, in days, if the user’s account supports password life-times
# passwd -x 10 user
-n This will set the minimum password lifetime, in days, if the user’s account supports password life-times. Available to root only
# passwd -n 10 user
-i This will set the number of days which will pass before an expired password for this account will be taken to mean that the account is inactive and should be disabled, if the user’s account supports pass-word lifetimes
# passwd -i 10 user
-w This will set the number of days in advance the user will begin receiving warnings that her password will expire, if the user’s account supports password lifetimes
# passwd -w 10 user
-S This will output a short information about the status of the password for a given account
# passwd -S user
   user PS 2009-09-12 0 99999 7 -1 (Password set, MD5 crypt.)