It is really simple to change the password for specific user on various Linux distros like Ubuntu,Fedora,Linux Mint,Debian etc.
Note that If you are a normal user then you can only change your password only and Super User or Administrator can change password for any user in a system.
Login as a root using the following command
$ sudo -s
Now to change the password for a user named “vividvilla” execute the following command
$ passwd vivek
Now you will be prompted to enter new password for the specified user
Enter new UNIX password:
Retype new UNIX password:
passwd: password updated successfully
Now to see what you can do with the passwd command execute the following
$ passwd -help
you will get to see something like below
Options: -a, --all report password status on all accounts -d, --delete delete the password for the named account -e, --expire force expire the password for the named account -h, --help display this help message and exit -k, --keep-tokens change password only if expired -i, --inactive INACTIVE set password inactive after expiration to INACTIVE -l, --lock lock the password of the named account -n, --mindays MIN_DAYS set minimum number of days before password change to MIN_DAYS -q, --quiet quiet mode -r, --repository REPOSITORY change password in REPOSITORY repository -S, --status report password status on the named account -u, --unlock unlock the password of the named account -w, --warndays WARN_DAYS set expiration warning days to WARN_DAYS -x, --maxdays MAX_DAYS set maximum number of days before password change to MAX_DAYS
Now lets check the status of the user “vividvilla”
$ passwd -S vividvilla
the output will be
vividvilla P 06/07/2012 0 99999 7 -1
From the above output you can find that the last password change occurred on 06/07/2012