Question

The default shell on the the system is csh but I want to write a script in bash. How do I write a script that will run bash and then convert back to csh at the end.

I tried this but it doesn’t work:

bash
var=Hello
echo $var
csh

Answer 1

You don’t need to change shells back again. When the script is run, it will be run by a sub-shell (which exits at the end of the script), and the parent shell is unchanged. So, as already suggested, the only thing you have to do is ensure the script is run by the correct shell, and the ‘shebang’ is the way to do that:

#!/bin/bash
var=Hello
echo $var

That’s all it takes.