Shell Script Shebang
The #! syntax is used in scripts to indicate an interpreter for execution under UNIX / Linux operating systems. The directive must be the first line in the Linux shell script and must start with shebang #!.
The sharp sign (#) and the bang sign (!) thats why called is the shebang. (sharpbang)
Shebang starts with #! characters and the path to the bash or other interpreter of your choice. Make sure the interpreter is the full path to a binary file. For example: /bin/bash.
- If a script does not contain a shebang the commands are executed using your shell.
- you can print SHELL variable to show which shell you are using.
- Different shells have slightly varying syntex
- you can see all the available shells in /etc/shells file in Linux operating system.
- It makes shell scripts more like actual executable files,
- because they can be the subject of 'exec.'
- If you do a 'ps' while such a command is running, the real name appears instead of 'sh' or 'bash'. Likewise, system accounting is done based on the real name.
- It will allow other interpreters to fit in more smoothly.
┌──(gaurav㉿learning-ocean)-[~/shellscript-youtube] └─$ cat /etc/shells
let's run a script with other interpreter. create a file using the below snippts
"Hello this is python script")print(
now let's change the mode and give the execute permission to file. and execute it.
┌──(gaurav㉿learning-ocean)-[~/shellscript-youtube] └─$ chmod +x second.sh ┌──(gaurav㉿learning-ocean)-[~/shellscript-youtube] └─$ ./second.sh hello world from python program