Linux and UNIX don't care about the filename at all. They check the first few bytes in the file to see what it is.

All the top line does is tell the OS what shell to use.

If you want to use tcsh, it should be #!/bin/tcsh

If you want to use sh, it should be #!/bin/sh

They both have 'set', actually. But they're not the same 'set'. So it depends which programming language you have been writing for!

Easy:

Code:

VAR="something"

Note that you can't put spaces between VAR, =, and ". like you might in tcsh. It has to be VAR="... with no spaces at all except inside quotes. This is because of the way BASH lets you set variables before running a program:

Code:

http_proxy="localhost:3128" wget www.website.com

which would export http_proxy only for wget. csh doesn't have that feature. Try the advanced bash scripting guide. Quite a lot of it will apply to any bourne shell.

bash, ksh, and sh are all bourne shells. bash and ksh are different extensions on the basic 'sh', and should still be able to run plain 'sh' code fine. But if you use arrays for example, it won't work in a basic 'sh' shell. If it does on your system, that's often because sh is just a link to bash in some linux systems.

csh and tcsh are definitely not bourne shells at all.