use URI;
my $dir='acm';
...looping through the file 
  ...$foo contains the URL from the logfile
  my $u=new URI($foo);
  if($u->path()=~/^\/$dir\//){
    .. do stuff in here 'cause we got an "/acm/" line
  }
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I might write code something like this:

my $dir = "/acm";

#  open file

while (<LOG>) {
    next unless /^\Q$dir\E/;
    # do something with $_ because it matches
}
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Perl first does double-quotish expansion ( how does this phrase seem to appear in all my posts? ) before passing anything to the regex engine. In this case, the regex engine is seeing something like /^\//acm\//. Which makes me think it is returning any line beginning with a '/'.

You could also try using the quotemeta modifiers \Q and\E which cause perl to protect all special characters with backslashes. To do this, your regex would look like /\Q$dir\E/. I had mixed luck with the quotemeta stuff a long time ago. It may work better now or your mileage may vary.

Mik
Mik Firestone ( perlus bigotus maximus )

if ($url =~ /\/$dir\//) { #... some stuff ...<br>
};
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#!/usr/bin/perl -w
#
# error-report.pl
#
# usage:
#  error-report.pl <dir> <error>
# where:
#  <dir> is the directory of the application
#  <error> is the number of the error code
#
# requires a filtered copy of a log file to exist.
#
# v0.1, jh8@ornl.gov, 5/12/2000
#

use strict;
# my $file = shift;
my $dir = shift;
my $error = shift;
$error = " ".$error." ";
open (LOG, "/usr/local/apache/logs/access_log") || die "Can't open log
+file: $!";
my (@entries, @log, %report, @list);

while (<LOG>) {
        my $url = (split())[6];
        if ($url =~ /^\/$dir\// && /$error/) {
                if (exists $report{$url}) {
                        $report{$url}++;
                } else {
                        $report{$url} = 1;
                }
        }
}
close LOG;
@list = sort {$report{$b} <=> $report{$a}}
        keys %report;
foreach (@list) {
        print "$_:  $report{$_}\n";
}
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Instead of your current while loop try this one which should be somewhat faster. I replaced your first regular expressions with a "substr eq" combination.

my $dir='/acm/';
my $strlen=length ($dir)

while (<LOG>) {
  my $url = (split())[6];
  if ((substr($url,0,$strlen) eq $dir) && ($url=~/$error/)) {
    if (exists $report{$url}) {
      $report{$url}++;
    } else {
      $report{$url} = 1;
    }
  }
}
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I benchmarked this using some sample data I made up and it is about %35 faster than the original version. Your performance may vary.

Regular-expressions are slower than straight string operations. So if you can accomplish what you want with string operations and performance matters, then you can tune your code by replacing some regular-expressions with string operations (only feasible for simple regular-expressions).

Your code looks good, but in order for me to get the right error codes, $url needs to be checked either against the entire line, or against $_[-1]. Thanks again, JJ

index(), in turn, may be a little faster than substr(). And replacing the regex on the error code should help, too. [code removed to protect the innocent] Update:

index() is faster when the match occurs at the beginning of the string, but substr() is much better when there is no match at all, which happens quite a lot in this application.

$dir = "/$dir/";
my $strlen = length $dir;
while (<LOG>) {
    my ($url, $code) = (split)[6,8];
    if (substr($url, 0, $strlen) eq $dir && $code == $error) {
        $report{$url}++;
    }
}
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Put the /o modifier on the end of those regexes. Since $dir and $error don't appear to change at all during the loop, you can optimize the regexp by only building it once. Could save some time.

$dir = "/acm/"; ## avoid worrying about escaping slashes
if (m/($dir.*) /) {
  print "The path is $1!\n";
}
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