How to use the command 'exit' (with examples)
The ’exit’ command is used to exit the current shell. It allows you to terminate the current shell session and return to the previous environment.
Use case 1: Exit the shell with the exit code of the last command executed
Code:
exit
Motivation: Exiting the shell with the exit code of the last command executed can be useful in scripts or automation tasks where you want to propagate the exit code to the calling process. This allows the calling process to determine whether the execution was successful or not.
Explanation:
- The ’exit’ command itself doesn’t take any arguments.
- When invoked without any arguments, the ’exit’ command uses the exit code of the last executed command as its own exit code.
- The exit code is a numerical value indicating whether the previous command executed successfully or encountered an error.
Example output:
Suppose the last executed command has an exit code of 0 (indicating success), running exit without any arguments will exit the shell with an exit code of 0.
Use case 2: Exit the shell with the specified exit code
Code:
exit exit_code
Motivation: Exiting the shell with a specified exit code can be helpful when you want to explicitly indicate a specific status or error condition to the calling process. This can be useful in scripts or programs where different exit codes convey different meanings.
Explanation:
- The ’exit’ command can take an optional argument, which specifies the exit code.
- The ’exit_code’ argument is a numerical value representing the desired exit code.
- Once the ’exit’ command is executed with a specified exit code, the shell exits and returns the specified exit code to the calling process.
Example output:
Running exit 1 will exit the shell with an exit code of 1, indicating an error condition or failure.
Conclusion:
The ’exit’ command is a handy utility for terminating the current shell session. Whether you want to use the exit code of the last command executed or specify a custom exit code, the ’exit’ command provides the flexibility to control the exit status of the shell session.
