# note that a simple pure perl version using 3arg open and
# e.g. $count=$contents=~s/$argument/$&/g will have 
# about the same code length; besides offering way more
# **cute** regexes... 

$ENV{file}=$file;         # protect filename from shell interpolation
$ENV{argument}=$argument; # also protect non-trivial regexes from shell!

# upd: either -H OR /dev/null, sigh. a very telling misread of mine
$results=`grep -c -H "\$argument" "\$file"`; # /dev/null`; # note \$ instead of \"