Fix “Exec format error” When Running Scripts With run-parts Command

When I was trying to run all scripts in a directory using run-parts command, I encountered with an error - "run-parts: failed to exec script.sh: Exec format error". The scripts worked just fine when I directly execute them like "./script.sh" and "sh script.sh". But they didn't work when I ran them with run-parts command. For those wondering, the run-parts command will run all scripts in a directory. If you got an error like this while running a script, this quick tip will help you to fix "Exec format error" when running scripts with run-parts command in Linux.

Fix "Exec format error" When Running Scripts With run-parts Command

To run all scripts in the Documents folder, I ran:

$ run-parts --regex '^s.*\.sh$' Documents

I got the following error message:

run-parts: failed to exec Documents/script1.sh: Exec format error
run-parts: Documents/script1.sh exited with return code 1
run-parts: failed to exec Documents/script2.sh: Exec format error
run-parts: Documents/script2.sh exited with return code 1
run-parts: failed to exec Documents/script3.sh: Exec format error
run-parts: Documents/script3.sh exited with return code 1
run-parts: failed to exec Documents/script4.sh: Exec format error
run-parts: Documents/script4.sh exited with return code 1

To fix "Exec format error", you need to add a shebang at the start of your scripts so the kernel will know how to run them. For those wondering, a shebang is the character sequence consisting of the characters number sign and exclamation mark (#!) at the beginning of a script. When you add the shebang at the start of a text file, it is interpreted as an executable file.

Most scripts starts with a shebang. Here are some typical shebang examples.

Bourne shell, or a compatible shell:

#!/bin/sh

Bash:

#!/bin/bash

Perl:

#!/usr/bin/perl

Python 2.x:

#!/usr/bin/python

Python 3.x:

#!/usr/bin/python3

This is what we call a shebang.

Now, let us get back to the topic. Edit your scripts using your favorite editor:

$ nano Documents/ostechnix.sh

Add the following shebang at the beginning of the script:

#!/bin/sh

Now you can be able to run the scripts with run-parts command without any issues using run-parts command.

Update:

As one of our reader Mr.Danesh mentioned in the comment section below, Instead of hard-coding the path of the interpreter, e.g.

#!/usr/bin/python3

We can use:

#!/usr/bin/env python3

This is more portable in case the interpreter is installed in some other (non-default) directory. env is a shell command for Unix and Unix-like operating systems. It is often used by shell scripts to launch the correct interpreter.

You can also use ShellCheck utility to find problems in your shell scripts.

• ShellCheck – A Free Utility To Find Bugs In Your Shell Scripts

Hope this helps.