How do you make a Bash script executable

Making a Bash script executable involves two main steps:

1. Create the script (if you haven't already).
2. Change the file's permissions to make it executable.

Step-by-Step Guide to Make a Bash Script Executable

1. Create the Bash Script

If you don't have a script yet, you can create one using any text editor. For example, let's create a simple script called myscript.sh.

Open a terminal and use a text editor to create the script file. Here's an example using nano:

nano myscript.sh

In the editor, write your script. For example:

#!/bin/bash
echo "Hello, World!"

After writing your script, save the file. In nano, press Ctrl + O to save and Ctrl + X to exit the editor.

2. Make the Script Executable

Now that you have a script file (myscript.sh), you need to change its permissions to make it executable.

Use the chmod command to do this:

chmod +x myscript.sh

• chmod is the command to change file permissions.
• +x adds the "execute" permission for the user, allowing the script to be run as a program.

3. Run the Script

Once you've made the script executable, you can run it.

If the script is in your current directory, use the ./ syntax to run it:

./myscript.sh

This should output:

Hello, World!

Understanding chmod +x

• chmod: The command to change file permissions.
• +x: This part adds the execute (x) permission. Without this, you can’t run the script as a program directly.
• Example with chmod: If you run chmod 755 myscript.sh, it gives full permissions to the owner (read, write, execute), and read and execute permissions to the group and others.

Example Permissions:

You can check the file permissions using ls -l:

ls -l myscript.sh

Before you run chmod +x:

-rw-r--r-- 1 user user 44 Nov 29 14:30 myscript.sh

After running chmod +x:

-rwxr-xr-x 1 user user 44 Nov 29 14:30 myscript.sh

The key change is the addition of the x in the permissions (rwx for the owner, r-x for group and others).

Notes:

• Shebang (#!/bin/bash): It's a good practice to include the shebang (#!/bin/bash) at the top of your script. It tells the system that the script should be executed using the Bash shell, no matter what shell the user is currently in.

• Running Scripts in Other Directories: If your script is located in a different directory (not the current one), you can either specify the full path, or if you want to run it from anywhere, add its directory to the system's PATH.