Apache Cookbook, 2nd Edition

Logging User Directories

Problem

You want each user directory Web site (i.e., those that are accessed via http://server/~username) to have its own logfile.

Solution

In httpd.conf, add the directive:

CustomLog "|/usr/local/apache/bin/userdir_log" combined

Then, in the file /usr/local/apache/bin/userdir_log, place the following code:

#!/usr/bin/perl

my $L = '/usr/local/apache/logs'; # Log directory

my %is_open = (); # File handle cache
$|=1;
open(F, ">>$L/access_log"); # Default error log

while (my $log = <STDIN>) {
    if ($log =~ m!\s/~(.*?)/!) {
        my $u = $1;
        unless ($is_open{$u}) {
            my $fh;
            open $fh, '>>' . $L . '/'. $u;
            $is_open{$u} = $fh;
        }
        select ($is_open{$u});
        $|=1;
        print $log;
    }
    else {
        select F;
        $|=1;
        print F $log;
    }
}

close F;
foreach my $h (keys %is_open) {
    close $h;
}

Discussion

Usually, requests to user directory Web sites are logged in the main server log, with no differentiation between one user’s site and another. This can make it very hard for a user to locate log messages for their personal Web site.

The recipe above allows you to break out those requests into one logfile per user, with requests not going to a userdir Web site going to the main logfile. The log handler can, of course, be modified to put all log messages in the main logfile as well as in the individual logfiles.

In order to lessen the amount of disk activity necessary, file handles are cached, rather than opened and closed with each access. This results in a larger number of file handles which are open at any given ...