Both Linux and UNIX-like operating systems use the passwd command to change user password.

Changing user passwords on Linux

• First sign on or “su” or “sudo” to the “root” account on Linux, run: sudo -i.
• Then type, passwd tom to change a password for tom user.
• The system will prompt you to enter a password twice.

How do I find my root password in Linux?

Method 1 With the Current Root Password

1. Open a terminal window.
2. Type su at the command prompt, and press ↵ Enter .
3. Type the current root password, then press ↵ Enter .
4. Type passwd and press ↵ Enter .
5. Type a new password and press ↵ Enter .
6. Retype the new password and press ↵ Enter .
7. Type exit and press ↵ Enter .

How do I change a user password in Ubuntu?

How to Change sudo Password in Ubuntu

• Step 1: Open the Ubuntu command line. We need to use the Ubuntu command line, the Terminal, in order to change the sudo password.
• Step 2: Log in as root user. Only a root user can change his/her own password.
• Step 3: Change the sudo password through the passwd command.
• Step 4: Exit the root login and then the Terminal.