#!/tools/packarch/public/perl/5.8.8/bin/perl
use strict;
use warnings;

open(my $file,  "<",  "input.txt")  or die "Can't open input.txt: $!";
my $string = "icecream";

while (<$file>)  
{
 if (/$string/)
 {
        print "found string $string\n";
 }
 else
 {
        my $notfound = "not found";
 }
}
if (my $notfound eq "not found")
{
print "string not found\n";
}