How to Check Exit Status for Command in Linux

When working on a Linux system, every command you run returns a status code (also called an exit status or return code) that tells you whether it ran successfully or failed.

As a Linux user, especially if you’re learning shell scripting or troubleshooting, knowing how to check the exit status of a command is super important.

In this article, I’ll explain what exit status means, how to check it, and why it matters.

What is Exit Status in Linux?

Whenever you run a command in Linux, the system quietly gives it a scorecard at the end, which is just a number called the exit status (or return code).

• If the number is 0, it means, the command ran successfully, without any errors.
• If the number is not 0, it means, the command failed to run in some way.

Think of it like this:

• 0 = “All good!”
• 1 = “Something went wrong (general error)”
• 2, 127, 126, etc. = Different kinds of problems, like “file not found” or “command not executable“.

You don’t always see these numbers printed on the screen, but Linux stores them in a special variable called $?. You can check it anytime to know whether your last command worked or failed.

Tip: These exit codes are especially important when you write Bash scripts because they help you make decisions depending on whether a command passed or failed.

How to Check Exit Status of a Command

In Linux, the exit status of the last command you ran is stored in a special shell variable called:

$?

The best way to understand exit status is by actually running commands.

Example 1: Successful Command

ls
echo $?

What happens here:

• First, ls lists the files in your current directory.
• Since the command worked without any issue, Linux sets the exit status to 0.
• When we immediately check the status using echo $?, it prints 0.

A 0 exit code always means success. So in this case, the ls command did exactly what we expected.

Example 2: Failed Command

ls /nonexistent
echo $?

What happens here:

• We tried to list files inside a directory called /nonexistent.
• That directory does not exist on the system, so the ls command fails.
• Linux then sets the exit status to a non-zero number (in this case 2).
• When we check with echo $?, we see:

Example 3: Using Exit Status in a Script

Exit statuses become really useful when you use them inside shell scripts, because scripts often need to make decisions based on whether a command succeeded or failed.

Let’s look at a simple example:

#!/bin/bash

ls /etc > /dev/null
if [ $? -eq 0 ]; then
    echo "Command successful!"
else
    echo "Command failed!"
fi

What happens here:

• If the ls command works → prints “Command successful!”.
• If it fails → prints “Command failed!”.

A Cleaner Way: Using && and ||

Instead of checking $? every time, you can chain commands:

• command && echo "Success" → runs the second command only if the first succeeded.
• command || echo "Failed" → runs the second command only if the first failed.

Example:

ls /etc && echo "Found it!" || echo "Not found!"

Common Exit Status Codes

Here are some frequently seen exit codes:

Final Thoughts

The exit status is a small number, but it plays a big role in running commands interactively or writing shell scripts, understanding exit codes helps you debug problems and control your workflow.

Next time a command doesn’t work as expected, don’t just look at the error message, just check the exit status too!