The first line of your script tells UNIX which shell you want to use. The following selects the C-shell.
#!/bin/csh
Somewhat perversely, the # is actually the comment character.
That's UNIX for you. However, its presence alone starting the first
line will normally be sufficient to run a script in the C shell.
Most of the examples in this document are script excerpts, and so do not
include the #!/bin/csh.
C-shell Cookbook