Possible Malicious Use
Its always a good idea to be warned of all the ways in which something can be used for evil. Shebang can be used for evil. A shebang only specifies the path to an executable, and the OS assumes that the executable is an interpreter to run the script on. But we can run any executable using a shebang.
For instance, we can create a very innocent-looking and seemingly harmless shellscript file, which performs nothing dangerous, but then give it a shebang which invokes an executable of my choice. This can include a malicious executable.
Before running a script which has its executable flag enabled using chmod +x, it is a good idea to quickly go over the script if you don’t know where its from. Lots of people ignore comments in the script while going over it, but it is important to check the shebang. The shebang starts with a ‘#’ and most editors give it the same syntax highlighting as any other comment, but always make sure to quickly glance at the shebang before running a script.
Using Shebang in Linux
Imagine you’re working on a Linux computer and have a recipe with instructions written in different languages. But your computer only understands English! That’s where the shebang comes in. It’s like a tiny label at the beginning of the recipe that tells your computer which “translator” to use for each language. This magic symbol, #!
, followed by the interpreter’s path, is the key to understanding and running all sorts of scripts on your system.