NAME

Apache::LogRegex - Parse a line from an Apache logfile into a hash

VERSION

version 1.70

SYNOPSIS

use Apache::LogRegex;

my $lr;

eval { $lr = Apache::LogRegex->new($log_format) };
die "Unable to parse log line: $@" if ($@);

my %data;

while ( my $line_from_logfile = <> ) {
    eval { %data = $lr->parse($line_from_logfile); };
    if (%data) {
        # We have data to process
    } else {
        # We could not parse this line
    }
}

# or generate a closure for better performance

my $parser = $lr->generate_parser;

while ( my $line_from_logfile = <> ) {
    my $data = $parser->($line_from_logfile) or last;
    # We have data to process
}

DESCRIPTION

Overview

Designed as a simple class to parse Apache log files. It will construct a regex that will parse the given log file format and can then parse lines from the log file line by line returning a hash of each line.

The field names of the hash are derived from the log file format. Thus if the format is '%a %t \"%r\" %s %b %T \"%{Referer}i\" ...' then the keys of the hash will be %a, %t, %r, %s, %b, %T and %{Referer}i.

Should these key names be unusable, as I guess they probably are, then subclass and provide an override rename_this_name() method that can rename the keys before they are added in the array of field names.

This module supports variable spacing between elements, so if you have more than one space between elements in your format or in your log file, that should be OK.

SUBROUTINES/METHODS

Constructor

Apache::LogRegex->new( FORMAT )

Returns a Apache::LogRegex object that can parse a line from an Apache logfile that was written to with the FORMAT string. The FORMAT string is the CustomLog string from the httpd.conf file.

Class and object methods

parse( LINE )

Given a LINE from an Apache logfile it will parse the line and return all the elements of the line indexed by their corresponding format string. In scalar context this takes the form of a hash reference, in list context a flat paired list. In either context, if the line cannot be parsed a false value will be returned.

generate_parser( LIST )

Generate and return a closure that, when called with a line, will return a hash reference containing the parsed fields, or undef if the parse failed. If LIST is supplied, it is interpreted as a flattened hash of arguments. One argument is recognised; if reuse_record is a true value, then the closure will reuse the same hash reference each time it is called. The default is to allocate a new hash for each result.

Calling this closure is significantly faster than the parse method.

names()

Returns a list of field names that were extracted from the data. Such as '%a', '%t' and '%r' from the above example.

regex()

Returns a copy of the regex that will be used to parse the log file.

rename_this_name( NAME )

Use this method to rename the keys that will be used in the returned hash. The initial NAME is passed in and the method should return the new name.

CONFIGURATION AND ENVIRONMENT

Perl 5

DIAGNOSTICS

The various custom time formats could be problematic but providing that they are encased in '[' and ']' all should be fine.

Apache::LogRegex->new() takes 1 argument

When the constructor is called it requires one argument. This message is given if more or less arguments were supplied.

Apache::LogRegex->new() argument 1 (FORMAT) is undefined

The correct number of arguments were supplied with the constructor call, however the first argument, FORMAT, was undefined.

Apache::LogRegex->parse() takes 1 argument

When the method is called it requires one argument. This message is given if more or less arguments were supplied.

Apache::LogRegex->parse() argument 1 (LINE) is undefined

The correct number of arguments were supplied with the method call, however the first argument, LINE, was undefined.

Apache::LogRegex->names() takes no argument

When the method is called it requires no arguments. This message is given if some arguments were supplied.

Apache::LogRegex->regex() takes no argument

When the method is called it requires no arguments. This message is given if some arguments were supplied.

BUGS

None so far

FILES

None

SEE ALSO

mod_log_config for a description of the Apache format commands

THANKS

Peter Hickman wrote the original module and maintained it for several years. He kindly passed maintainership on just prior to the 1.51 release. Most of the features of this module are the fruits of his work. If you find any bugs they are my doing.

AUTHOR

Original code by Peter Hickman <peterhi@ntlworld.com>

Additional code by Andrew Kirkpatrick <ubermonk@gmail.com>

LICENSE AND COPYRIGHT

Original code copyright (c) 2004-2006 Peter Hickman. All rights reserved.

Additional code copyright (c) 2013 Andrew Kirkpatrick. All rights reserved.

This module is free software. It may be used, redistributed and/or modified under the same terms as Perl itself.

cpanm Apache::LogRegex

perl -MCPAN -e shell
install Apache::LogRegex