#!/usr/local/bin/perl 
 
use strict; 
 
my $source = <<EOF; 
212.12.12.2 
199.2.3.1 
210.3.3.2 
212.12.12.2 212.12.12.2 
199.65.78.123 
112.34.55.6 
212.12.12.2 
199.88.77.12 
EOF 
 
my @rows = split ("\n", $source); 
my $ip = '212.12.12.2'; 
 
my $count;

foreach (@rows) { 
  $count++ if (/$ip/); 
} 
 
print "'$ip' found on $count of ", scalar (@rows), " lines\n"; 
 
$count = ($source =~ s/$ip/$ip/g); 
 
print "'$ip' found on $count of ", scalar (@rows), " lines\n"; 
 
$count = grep { /$ip/ } @rows; 
 
print "'$ip' found on $count of ", scalar (@rows), " lines\n";