#!/usr/bin/perl
#
# Copyright 2001-2004 The Apache Software Foundation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
#
# This script will take a combined Web server access
# log file and break its contents into separate files.
# It assumes that the first field of each line is the
# virtual host identity (put there by "%v"), and that
# the logfiles should be named that+".log" in the current
# directory.
#
# The combined log file is read from stdin. Records read
# will be appended to any existing log files.
#
%is_open = ();

while ($log_line = <STDIN>) {
    #
    # Get the first token from the log record; it's the
    # identity of the virtual host to which the record
    # applies.
    #
    ($vhost) = split (/\s/, $log_line);
    #
    # Normalize the virtual host name to all lowercase.
    # If it's blank, the request was handled by the default
    # server, so supply a default name.  This shouldn't
    # happen, but caution rocks.
    #
    $vhost = lc ($vhost) or "access";
    #
    # if the vhost contains a "/" or "\", it is illegal so just use
    # the default log to avoid any security issues due if it is interprted
    # as a directory separator.
    if ($vhost =~ m#[/\\]#) { $vhost = "access" }
    #
    # If the log file for this virtual host isn't opened
    # yet, do it now.
    #
    if (! $is_open{$vhost}) {
        open $vhost, ">>${vhost}.log"
            or die ("Can't open ${vhost}.log");
        $is_open{$vhost} = 1;
    }
    #
    # Strip off the first token (which may be null in the
    # case of the default server), and write the edited
    # record to the current log file.
    #
    $log_line =~ s/^\S*\s+//;
    printf $vhost "%s", $log_line;
}
exit 0;


Error:
Can't open www.domain2.com.log at ./split-logfile line 54, <STDIN> line 37424

line 37423:

www.domain1.com 24.234.98.16 - - [02/Aug/2006:18:13:52 -0700] "GET /t2/header_fruit_2bg.jpg HTTP/1.1" 304 - "www.domain1.com/" "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.2; SV1; .NET CLR 1.1.4322)"

line 37424:

www.domain2.com 72.30.135.217 - - [02/Aug/2006:18:13:52 -0700] "GET /robots.txt HTTP/1.0" 404 208 "-" "Mozilla/5.0 (compatible; Yahoo Slurp; help.yahoo.com/help/us/ysearch/slurp)"