#!/usr/bin/perl -l
print "Enter the file name ";
$filename=<STDIN>;
chomp $filename;
unless(open(FILENAME,$filename))
{
print "Cannot open file \"$filename \"\n\n";
exit;
}
@sequence =<FILENAME>;

$seq =join(' ',@sequence);
$seq=~s/\s//g;
for($i=0;$i<2;$i++){
print "subsequence to search";
my $find = <STDIN>;

my ($before, $after) = $seq =~ /(..)$find(..)/;
print "before: $before";    
print "after:  $after"; 
open (MYFILE, '>>write.txt');
print MYFILE "$before\n";
print MYFILE "$after\n";
close (MYFILE);
}