Beefy Boxes and Bandwidth Generously Provided by pair Networks
Perl Monk, Perl Meditation

Comment on

( #3333=superdoc: print w/ replies, xml ) Need Help??

My friend is having two text files a and b. a is having 400 lines and b is having 50000 lines. He needs to compare the files and write in to a new log file where the matched contents should be written.

My friend's boss thinks that fetching 'a' line by line and comparing it with the file b at a stretch is effecient. But what my friend suggested is to open the file 'b' line by line and compare it with a regular expression framed by joining all the lines of a with '|'. My friend asked me which one is better and efficient. I thought that what my friend suggested is efficient.

Monks, please suggest us which method we should go for. Is there any other effecient way to do this?

Million thanks in advance.

Murugesan Kandasamy
use perl for(;;);

In reply to Efficient code. by murugu

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 surveying the Monastery: (11)
    As of 2015-11-25 00:34 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 (666 votes), past polls