#!/bin/tcsh
# Usage:        ren arg1 arg2
#               changes the string arg1 in the names of files
#               in the working directory into the string arg2
if ($#argv != 2) goto usage
foreach i ( *$1* )
	mv $i `echo $i | sed -n s/$1/$2/p`
end
exit 0

usage:
echo "Usage: ren arg1 arg2"
exit 1