in reply to Design hints for a file processor

If you have no other occurences of Category, you can simply search for that: 
#!/usr/bin/perl
use strict;
use warnings;
for (<DATA>){
    if (m/^\s*Category (.*)$/){
        print $1, $/;
    }
}

[download]

If you want to really parse the file, I'd recommend a simple recursive descending parser, see Parsing with Regexes and Beyond for an explanation. The tokens would be just the lines.

Replies are listed 'Best First'.
Re^2: Design hints for a file processor
by PhilHibbs (Hermit) on Jul 07, 2008 at 12:18 UTC
    Yes, that's exactly what I do currently - the script is basically a whole load of special cases with no real structure to it. Well, this is my actual code for that:

    $cat = $1 if /^\s+Category "(.+)"/;

    I prefer this notation, I know some people don't.

[reply]
[d/l]
      If you want structure, use a real parser. Here is one, albeit a bit hacked up:
      Read more... (4 kB)

      It returns a sort of parse tree with an array ref for each block or line, where blocks look like ['BLOCK', $name_of_block, @lines_in_this_block] and lines look like ['LINE', $key, $value].

      Depending on your exact data format and what you want to extract, hashes might be more suitable.

[reply]
[d/l]
[select]
        The file is up to half a gigabyte, I'm not keeping all that in memory. I could split it up by job, I suppose.
[reply]

In Section Seekers of Perl Wisdom