passwd (change password) in Linux CLI - Step-by-Step Execution

Concept Flow - passwd (change password)

User runs 'passwd'

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Prompt: Enter current password

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User inputs current password

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Prompt: Enter new password

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User inputs new password

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Prompt: Confirm new password

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User confirms new password

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System checks passwords match

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Password [Error: Passwords do not match

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Restart new password prompt

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Success message

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Exit

The passwd command asks for the current password, then the new password twice, checks if they match, and changes the password if all is correct.

Execution Sample

Linux CLI

passwd
Enter current password:
Enter new password:
Retype new password:

This sequence shows the prompts when changing a password using the passwd command.

Execution Table

Step	Action	User Input	System Check	Result/Output
1	Run 'passwd' command			Prompt: Enter current password:
2	User enters current password	current_password	Verify current password	If correct, prompt: Enter new password:
3	User enters new password	new_password		Prompt: Retype new password:
4	User retypes new password	new_password	Check if new passwords match	If match, password changed successfully
5	If passwords do not match	mismatched_password	Check if new passwords match	Error: Passwords do not match, prompt again for new password
6	Password changed			Success message: password updated
7	Exit			Return to shell prompt

💡 Execution stops after successful password change or user aborts.

Variable Tracker

Variable	Start	After Step 2	After Step 3	After Step 4	Final
current_password	unset	user input	user input	user input	used for verification
new_password	unset	unset	user input	user input	used for confirmation and update
password_match	unset	unset	unset	true/false	true if passwords match, else false

Key Moments - 3 Insights

Why does passwd ask for the new password twice?

To make sure the new password is typed correctly both times. If they don't match (see execution_table step 5), it asks again to avoid mistakes.

What happens if the current password is entered incorrectly?

The system will reject it and not proceed to new password prompts. This is shown in execution_table step 2 where verification fails and passwd exits or retries.

Can you see the password as you type it?

No, for security reasons the input is hidden (no characters shown). This prevents others from seeing your password.

Visual Quiz - 3 Questions

Look at the execution_table, what happens at step 4 if the new passwords match?

A Password is changed successfully

B Error message is shown

C User is asked to enter current password again

D The command exits without changes

💡 Hint

Check the 'Result/Output' column at step 4 in the execution_table

At which step does the system verify the current password?

A Step 1

B Step 2

C Step 3

D Step 4

💡 Hint

Look at the 'System Check' column in the execution_table

If the new passwords do not match, what does the system do next?

A Changes the password anyway

B Exits the command immediately

C Shows an error and asks to re-enter new password

D Asks for current password again

💡 Hint

See the row for step 5 in the execution_table under 'Result/Output'

Concept Snapshot

passwd command changes user password
1. Enter current password for verification
2. Enter new password twice to confirm
3. If new passwords match, password updates
4. If mismatch, prompts again
5. Password input is hidden for security

Full Transcript

The passwd command is used to change a user's password on Linux. When you run passwd, it first asks you to enter your current password to confirm your identity. Then it asks you to enter a new password twice to make sure you typed it correctly. If the two new passwords match, the system updates your password and shows a success message. If they don't match, it shows an error and asks you to enter the new password again. Passwords are not shown on screen as you type for security. This process ensures your password is changed safely and correctly.