Shell Scripting

You have learned in the previous section that UNIX shells can take commands from a file also. Such files are called shell scripts.
In this section we will explore how to write your own shell scripts.

Shebang (UNIX)

In UNIX, shebang is a line which is added at the beginning of any script that you want to run as a standalone executable.
The line should starts with #!.
A shebang tells the shell which interpreter to use and its location in order to execute the script. For example,
- If I write a script for Bash Shell then I would have to include the following at the beginning of the script.
```
#!/bin/bash
```
- If I write a script for Python then I would have to include the following at the beginning of the script.
```
#!/usr/bin/env python3
```
A shebang gives the script the ability to be executed as an executable.