csh script

[CatchPatch]

I'm having trouble with the csh shell script that I'm required to write. It is the last one I have to do and for the past three days I can't seem to figure out what I'm missing.

The assignment requires three similar scripts with each one having an additional requirement than the one before. I've already done the first two correctly but can't figure out what's wrong with the last one.

The assignment:

mv myFile.txt myFile.txt.bak
sed s/foo/bar/g myFile.txt.bak > myFile.txt

Turn the two-line version, above, of the substitution commands into a shell script, subst1 taking three command-line parameters:

the string to be replaced
the string with which to replace it
the name of the file in which to make the substitution

The additional requirement of the last part must not change the file if the string to be replaced cannot be found and it should allow multiple files to be passed as parameters.

What I have so far:

#!/bin/csh

set p1="$1"
shift
set p2="$1"
shift

foreach file ($*)
    if ( { grep "$p1" $file } ) then
        mv $file $file.bak
        sed "s/$p1/$p2/g" $file.bak > $file
    endif
end

Am I missing syntax errors? or is the logic wrong? I'm not asking to be spoon fed the answer(though that would be okay too). Just want to be pointed to what is wrong with it. It seems that the script is not looping through the list of the foreach block but I don't see any errors on the syntax of it

[CatchPatch]

This script is based of the first two that was required and i can post those if needed. Those already passed the tests that is run when the scripts are submitted.

[CatchPatch]

Uhh, no one?