# NAME

# NAME

Apache::LogFormat::Compiler - Compile a log format string to perl-code

# SYNOPSIS

use Apache::LogFormat::Compiler;

my $log_handler = Apache::LogFormat::Compiler->new("combined");
my $log = $log_handler->log_line(
$env,
$res,
$length,
$reqtime,
$time
);

# DESCRIPTION

Compile a log format string to perl-code. For faster generation of access\_log lines.

# METHOD

- new($fmt:String)

Takes a format string (or a preset template `combined` or `custom`)
to specify the log format. This module implements a subset of
[Apache's LogFormat templates](http://httpd.apache.org/docs/2.0/mod/mod\_log\_config.html):

%% a percent sign
%h REMOTE_ADDR from the PSGI environment, or -
%l remote logname not implemented (currently always -)
%u REMOTE_USER from the PSGI environment, or -
%t [local timestamp, in default format]
%r REQUEST_METHOD, REQUEST_URI and SERVER_PROTOCOL from the PSGI environment
%s the HTTP status code of the response
%b content length of the response
%T custom field for handling times in subclasses
%D custom field for handling sub-second times in subclasses
%v SERVER_NAME from the PSGI environment, or -
%V HTTP_HOST or SERVER_NAME from the PSGI environment, or -
%p SERVER_PORT from the PSGI environment
%P the worker's process id
%m REQUEST_METHOD from the PSGI environment
%U PATH_INFO from the PSGI environment
%q QUERY_STRING from the PSGI environment
%H SERVER_PROTOCOL from the PSGI environment

In addition, custom values can be referenced, using `%{name}`,
with one of the mandatory modifier flags `i`, `o` or `t`:

%{variable-name}i HTTP_VARIABLE_NAME value from the PSGI environment
%{header-name}o header-name header in the response
%{time-format]t localtime in the specified strftime format

- log\_line($env:HashRef, $res:ArrayRef, $length:Integer, $reqtime:Integer, $time:Integer): $log:String

Generates log line.

$env PSGI env request HashRef
$res PSGI response ArrayRef
$length Content-Length
$reqtime The time taken to serve request in microseconds. optional
$time Time the request was received. optional. If $time is undefined. current timestamp is used.

Sample psgi

use Plack::Builder;
use Time::HiRes;
use Apache::LogFormat::Compiler;

my $log_handler = Apache::LogFormat::Compiler->new(
'%h %l %u %t "%r" %>s %b "%{Referer}i" "%{User-agent}i" %D'
);
my $compile_log_app = builder {
enable sub {
my $app = shift;
sub {
my $env = shift;
my $t0 = [gettimeofday];
my $res = $app->();
my $reqtime = int(Time::HiRes::tv_interval($t0) * 1_000_000);
$env->{psgi.error}->print($log_handler->log_line(
$env,$res,6,$reqtime, $t0->[0]));
}
};
$app
};

# ADD CUSTOM FORMAT STRING

Apache::LogFormat::Compiler allows one to add a custom format string

my $log_handler = Apache::LogFormat::Compiler->new(
'%z %{HTTP_X_FORWARDED_FOR|REMOTE_ADDR}Z',
char_handlers => +{
'z' => sub {
my ($env,$req) = @_;
return $env->{HTTP_X_FORWARDED_FOR};
}
},
block_handlers => +{
'Z' => sub {
my ($block,$env,$req) = @_;
# block eq 'HTTP_X_FORWARDED_FOR|REMOTE_ADDR'
my ($main, $alt) = split('\|', $args);
return exists $env->{$main} ? $env->{$main} : $env->{$alt};
}
},
);

Any single letter can be used, other than those already defined by Apache::LogFormat::Compiler.
Your sub is called with two or three arguments: the content inside the `{}`
from the format (block\_handlers only), the PSGI environment (`$env`),
and the ArrayRef of the response. It should return the string to be logged.

# RECOMMENDED MODULE

If [POSIX::strftime::GNU](http://search.cpan.org/perldoc?POSIX::strftime::GNU) is available, Apache::LogFormat::Compiler uses it.
It's good for Windows and old Unices have limited strftime's formatting.

# AUTHOR

Masahiro Nagano <[email protected]>

# SEE ALSO

[Plack::Middleware::AccessLog](http://search.cpan.org/perldoc?Plack::Middleware::AccessLog), [http://httpd.apache.org/docs/2.2/mod/mod\_log\_config.html](http://httpd.apache.org/docs/2.2/mod/mod\_log\_config.html)

# LICENSE

Copyright (C) Masahiro Nagano

This library is free software; you can redistribute it and/or modify
it under the same terms as Perl itself.