apacheのログ(access_log)解析は、Apache::ParseLog 等のcpan moduleより正規表現

結局、これがお手軽。

apacheのログ(access_log)をパースするcpan moduleは多くあります

Regexp::Log::Common	Barbie / Regexp-Log-Common - search.cpan.org
Parse::AccessLogEntry	Marc Slagle / Parse-AccessLogEntry - search.cpan.org
Apache::ParseLog	Akira Hangai / Apache-ParseLog - search.cpan.org

多分、他多数に多くありますが、access_log程度のパースであれば、自前で正規表現しては?

access_log程度のパースの例

正規表現

($host, $ident, $user, $time, $request, $status, $bytes, $referer, $agent) =
  $line =~
  /^([^ ]*) ([^ ]*) ([^ ]*) \[([^]]*)\] "(.*?)" ([^ ]*) ([^ ]*) "(.*?)" "(.*?)"/o; 
# http://pmakino.jp/tdiary/20070907.html

sample script

#!/usr/local/bin/perl
use strict;
use CGI;
use Data::Dumper;

#refer to http://httpd.apache.org/docs/2.2/mod/mod_log_config.html
my $REGEXP = join(' ',
		  '^([^ ]*) ([^ ]*) ([^ ]*) \[([^]]*)\] "([^ ]*)(?: *([^ ]*)',
		  '*([^ ]*))?" ([^ ]*) ([^ ]*) "(.*?)" "(.*?)" (\d+)');

main(@ARGV);

sub main {
    my ($log_file) = @_;
    open(my $fh ,$log_file) or die "can't open $log_file $!";

    my $summary = {};
    while (my $line = <$fh>){
	chomp($line);
	#parse log
	my ($host, $ident, $user, $datetime, $method, $resource,
	    $proto, $status, $bytes, $referer, $agent, $time) =
		$line =~ /$REGEXP/o;

	#### something TODO
    }

    close($fh) or die "can't close $log_file $!";
}