perlquestion
Bio90
Hi all,
<p>I am trying to match a specific part of a line and print the line above and below it, in full.</p>
Through various internet searches I have found this code which I believe is suitable to the task:
<code>use strict;
use warnings;
open( my $fh, '<', 'input.txt') or die "Error opening file - $!\n";
open OUT, ">", "output.txt" or die "could not open output.txt $! \n";
my $this_line = "";
my $do_next = 0;
while(<$fh>) {
my $last_line = $this_line;
$this_line = $_;
if ($this_line =~ /<DATA>/) {
print OUT $last_line unless $do_next;
print OUT $this_line;
$do_next = 1;
} else {
print OUT $this_line if $do_next;
$last_line = "";
$do_next = 0;
}
}
close ($fh);
__DATA__
4386_7#8
4350_7#6
4414_1#6
4465_5#1
etc...</code>
<p>The data are not a line by themselves, rather they are part of a line.</p>
When I run this code the output produced is just a blank text file. It does not return any error messages, and I am sure that matches I am searching for are in the file I am searching.
<p>Any help as to what might be the problem would be much appreciated.</p>
Thanks in advance,
<p>Bio</p>