Shorts – How to Check Exit Status for Command in Linux

What is Exit Status in Linux?

When you run a command in Linux, the system returns a short scorecard at the end called the exit status (or return code).

• 0 means the command completed successfully with no errors.
• A non-zero value means the command failed in some way.

A simple mapping:

• 0 = “All good!”
• 1 = “General error”
• 2, 127, 126, etc. = Specific problems (e.g., “file not found,” “command not executable,” etc.)

You don’t always see these numbers on the screen, but Linux stores the last command’s exit status in a special variable: $?. You can check it anytime to determine whether the previous command succeeded 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:

$?

Example : Successful Command

ls
echo $?

What happens here:

• First, ls lists the files in your current directory.
• Since the command completed without errors, Linux sets the exit status to 0.
• When we check the status with echo $?, it prints 0.

Example : Failed Command

ls /notexisting
echo $?

What happens here:

• We try to list files in /notexisting, which doesn’t exist.
• The ls command fails, so Linux sets a non-zero exit status (here, 2).
• If we check with echo $?, we would see:

Example : Using Exit Status in a Script

Exit statuses are especially useful in shell scripts, where decisions depend on whether a command succeeded or failed.

Here’s a simple example:

#!/bin/bash

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

Common Exit Status Codes

Here are frequently seen exit codes:

Exit Code	Meaning
0	Success
1	General error
2	Misuse of shell command
126	Command found but not executable
127	Command not found
130	Script terminated by Ctrl+C
255	Exit status out of range

Final thoughts

The exit status is a small number with a big impact, whether you’re running commands interactively or writing shell scripts. Understanding exit codes helps you debug and control your workflow.

Next time a command doesn’t work as expected, don’t rely on the error message alone—check the exit status as well.