How can I efficiently match many different regex patterns in Perl?

Question

I have a growing list of regular expressions that I am using to parse through log files searching for \"interesting\" error and debug statements. I\'m currently breaking th

Answer 1

You can combine your regexes with the alternation operator |, as in: /pattern1|pattern2|pattern3/

Obviously, it won't be very maintainable if you put all of them in a single line, but you've got options to mitigate that.

• You can use the /x regex modifier to space them nicely, one per line. A word of caution if you choose this direction: you'll have to explicitely specify the space characters you expect, otherwise they'd be be ignored because of the /x.

• You can generate your regular expression at run-time, by combining individual sources. Something like this (untested):

  my $regex = join '|', @sources;
  while (<>) {
      next unless /$regex/o;
      say;
  }