Beefy Boxes and Bandwidth Generously Provided by pair Networks
Your skill will accomplish
what the force of many cannot

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??
By doing a 'Super Search', (located at the top of any PerlMonks page here), with the words 'find common lines', you will find similiar problems and solutions.

Only, they find lines in common rather than unique. But its not difficult to figure this the difference, I believe.

If the THIDS file isn't too large for your memory, you could read it into a hash to check against the 'mail.fil' for differences.

#!/usr/local/perl-5.12.3/bin/perl use strict; use warnings; open my $THIDS,"<", "THIDSerrs" or die "Could not open 'THIDSerrs' for + reading. $!"; my %data = map {$_ => 1} <$THIDS>; close $THIDS or die "Unable to close 'THIDSerrs' - reading. $!"; open my $mail, "<" , "mail.fil" or die "Could not open 'mail.fil' for +reading. $!"; open my $out, ">", "whatever.dat" or die "Unable to open 'whatever.dat +' for write. $!"; while (<$mail>) { print $out unless $data{$_}; } close $mail or die "Unable to close 'mail.fil' - reading. $!"; close $out or die "Unable to close 'whatever.dat' from writing. $!";

In reply to Re^2: use to files - grep one to eliminate entries from another file. by Cristoforo
in thread use to files - grep one to eliminate entries from another file. by newkendall

Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":

  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.
  • Log In?

    What's my password?
    Create A New User
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others having an uproarious good time at the Monastery: (8)
    As of 2015-12-01 04:22 GMT
    Find Nodes?
      Voting Booth?

      What would be the most significant thing to happen if a rope (or wire) tied the Earth and the Moon together?

      Results (792 votes), past polls