Demystifying the (Shebang): Kernel Adventures

Demystifying the #! (shebang): Kernel Adventures From my first experience creating a shell script, I learned about the shebang ( #! ), the special first line used to specify the interpreter for executing the script: #! /usr/bin/sh echo "Hello, World!" So that you can just invoke it with ./hello.sh and it will run with the specified interpreter, assuming the file has execute permissions. Of course, the shebang isn’t limited to shell scripts; you can use it for any script type: #! /usr/bin/python3 print( "Hello, World!" ) This is particularly useful because many bundled Linux utilities are actually scripts. Thanks to the shebang, you don’t need to explicitly invoke their interpreters. For example, there are two (very confusing) programs to create a user on Linux: useradd and adduser . One of them is the actual program that will create the user in the system, the other one is a utility that will create the user, the home directory and configure the user for you. Since I never reme ... Read full article.