Beefy Boxes and Bandwidth Generously Provided by pair Networks
Clear questions and runnable code
get the best and fastest answer
 
PerlMonks  

Comment on

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

Hi mdotpl,
it would probably help if you included a few lines of the format you're trying to parse. So here's just some general advice:

It hardly ever makes sense to read files in foreach(). It evaluates <> in list context, causing the whole file to be read into memory at once even if you only want to keep a small part of it. That's particularly important with log files that tend to be large.

The other thing is that you probably want a hash instead of an array there, to save the loop that searches for a matching ID later and speed up everything by orders of magnitude. So the first part should be:

while(<AUTH>) { chomp; if(/<my-regex-goes-here>/i) { $sessionID{$4} = 1; } }

Also note that if the session ID is in your fourth capture and you're not using the other three (or more), it would make sense not to capture in the first place. It reads easier and is faster.

With the hash, the rest can simply look like this (I've also renamed @list to reflect its purpose---"@list" doesn't really say anything as at-foo is always a list):

open(MSG) or die("couldn't open msg log"); while(<MSG>) { chomp; if(my ($id) =~ /<my-regex-goes-here(<capture the id>)>/i)) { push @matching_lines, $_ if $sessionID{$id}; } } close(MSG); print $_, "\n" foreach (@matching_lines);

If you don't need to do anything else with the lines, you could also omit the chomp (the regex will match anyway) and make the last bit a simple "print @lines"


In reply to Re: Parsing Logs by mbethke
in thread Parsing Logs by mdotpl

Title:
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!
  • 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
  • Outside of code tags, you may need to use entities for some characters:
            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?
    Username:
    Password:

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

    How do I use this? | Other CB clients
    Other Users?
    Others taking refuge in the Monastery: (13)
    As of 2014-09-23 14:51 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?

      How do you remember the number of days in each month?











      Results (223 votes), past polls