NAME

Apache::ConfigFile - Parse an Apache style httpd.conf config file

SYNOPSIS

   # 
   # Parse the standard Apache httpd.conf
   #
   use Apache::ConfigFile;
   my $ac = Apache::ConfigFile->read("/etc/apache/httpd.conf");

   # You can get at individual configuration commands using
   # the cmd_config() method:

   my $hostname = $ac->cmd_config('ServerName');
   my $doc_root = $ac->cmd_config('DocumentRoot');

   # Multiple values are returned as a list, meaning that you
   # can directly assign them to an array or even a hash:

   my @perlmods = $ac->cmd_config('PerlModule');
   my %ftypes   = $ac->cmd_config('FileTypeSuffix');

   # Then, you can reset the context of the calls using the
   # cmd_context() method so that you are accessing the 
   # appropriate values. For example, if you had a context 
   # block like
   #
   #   <VirtualHost "10.1.1.2">
   #       ServerName "www.mydomain.com"
   #       DocumentRoot "/www/mydomain.com/htdocs"
   #   </VirtualHost>
   #
   # You would get to this definition via:

   my $vh = $ac->cmd_context(VirtualHost => '10.1.1.2');
   my $vhost_server_name = $vh->cmd_config('ServerName');
   my $vhost_doc_root    = $vh->cmd_config('DocumentRoot');

   # If you had multiple VirtualHost declarations for a
   # given IP (as would be the case if you're using 
   # NameVirtualHosts), you could cycle through them with:

   for my $vh ($ac->cmd_context(VirtualHost => '10.1.1.3')) {
       my $vhost_server_name = $vh->cmd_config('ServerName');
       my $vhost_doc_root    = $vh->cmd_config('DocumentRoot');
   } 

   # In fact, even better you can "search" for one by specifying
   # an additional set of criteria to cmd_config(). To just get
   # the VirtualHost "docs.mydomain.com", for example, try:

   my $docs_svr = $ac->cmd_context(VirtualHost => '10.1.1.3',
                                   ServerName  => 'docs.mydomain.com');
   my $docs_base_dir = $docs_svr->cmd_config('DocumentRoot');

   # In addition, this module will automatically autoload
   # directive-based functions, meaning you can get to
   # commonly-used commands by name:

   my $host = $ac->server_name;
   my $root = $ac->server_root;
   my $html = $ac->document_root;

   # You also get the mod_perl dir_config() command to get
   # at PerlSetVar declarations by name. So, the block:
   #
   #   <Location /myapp>
   #       SetHandler perl-script
   #       PerlHandler Apache::MyApp
   #       PerlSetVar MyAppRoot "/usr/myapp"
   #       PerlSetVar MyAppRefresh "30m"
   #   </Location>
   #
   # Would be accessed as:

   my $loc = $ac->cmd_context(Location => '/myapp');
   my $app_root = $loc->dir_config('MyAppRoot');
   my $app_refr = $loc->dir_config('MyAppRefresh');

   # Finally, you get two other utility methods. The first
   # will return the current data structure verbatim, and
   # the second one will return a dump which you can print
   # out or parse or whatever:

   my %config = $self->data;
   warn "DEBUG: ", $self->dump, "\n";

DESCRIPTION

This module parses the Apache httpd.conf, or any compatible config file, and provides methods for you to access the values from the config file. The above examples show basic usage of this module, which boils down to reading a given config file and then using the cmd_config() and cmd_context() functions to access its information.

By default, the config file is parsed more or less "verbatim", meaning that directives are case-sensitive, variables are not interpolated, and so forth. These features can be changed by options given to the read() function (see below).

The read() function is the constructor, which reads in a configuration file and returns an object with methods that can be used to access directives from the file. The simplest usage is something like this:

use Apache::ConfigFile;
my $ac = Apache::ConfigFile->read("/path/to/httpd.conf");

Which would parse the Apache httpd.conf file and give you back an $ac object with the following methods:

cmd_config(): Used to access individual configuration commands
cmd_context(): Used to change the context of the commands you're accessing
dir_config(): Used to access values set via the PerlSetVar command (for mod_perl)

For more examples of standard Apache usage, you should read the "SYNOPSIS" above or skip down to the "FUNCTIONS".

In addition to reading an Apache config file, this module provides some options that allow the Apache syntax to be extended. This is useful if you're writing your own application and want to use a config file resembling Apache's.

use Apache::ConfigFile;
my $ac = Apache::ConfigFile->read(
                file => "/path/to/httpd.conf",
                ignore_case  => 1,
                expand_vars  => 1,
                fix_booleans => 1
         );

These options would allow us to write a custom config file looking like this:

BaseDir    "/export"
ImageDir   "$BaseDir/images"
BuildDir   "$BaseDir/images"

<Release "sw7">
    OfficialName "Software Update 7"
    BuildPath "$BuildDir/sw7/REL"         
    Platforms Solaris Linux IRIX HP-UX
    Supported Yes
</Release>

Then, you would be able to access it as follows:

use Apache::ConfigFile;
my $swcfg = Apache::ConfigFile->read("releases.conf");

# Note that case does not matter
my $rel = $swcfg->cmd_context(release => 'sw7');
my $ofn = $rel->cmd_config('bUiLdPaTh');

# This is autoloading + fix_booleans
unless ($rel->supported) {
    die "Sorry, that release is not supported";
}

There are several things to note. First, all our cmd_ functions are now case-insensitive, since we turned on the ignore_case flag (which is off by default). Second, notice a couple things about our unless statement. Since we specified fix_booleans, the words "Yes", "True", and "On" will be converted to 1 (true), and "No", "False", and "Off" will become 0 (false). As such, we can use these directives in boolean statements throughout our code.

In addition, since this module provides autoloading so that all config commands are turned into functions, you can access values directly, as shown by the statement $rel->supported. This statement is equivalent to the longer $rel->cmd_config('supported').

Finally, if you just wish to manually navigate the data structure (which is a huge hash of hashes of arrays) without using the accessor functions, you can return the thing verbatim:

my %conf = $ac->data;
print "Release is $conf{'release'}\n";

However, note that the internal representation is subject to change, so using the accessor functions is recommended.

FUNCTIONS

read(filename)

read(file => filename, opt => val, opt => val)

The read() function reads the configuration file specified and returns an object with methods to access its directives. read() has two calling forms. In the simplest version, you just specify a filename, and a new Apache::ConfigFile object is returned. Or, if you want to specify options, you specify each one as a key/value pair. For example:

# keep default options
my $ac = Apache::ConfigFile->read("httpd.conf");

# override the case sensitivity and boolean translation
my $ac = Apache::ConfigFile->read(file => "httpd.conf",
                                  ignore_case  => 1,
                                  fix_booleans => 1);

The list of valid options is:

file

Path to configuration file. If not provided then /usr/local/apache/conf/httpd.conf is used by default.

ignore_case

If set to 1, then all directives will be case-insensitive and stored in lowercase. Defaults to 0.

fix_booleans

If set to 1, then the words "Yes", "True", and "On" will be converted to 1 (true), and "No", "False", and "Off" will become 0 (false). This allows you to easily use these types of directives in if statements. Defaults to 0.

expand_vars

If set to 1, then you can reuse variables that you have defined elsewhere in the config file by prefixing them with a $. For example:

BaseDir   "/export"
HomeDir   "$BaseDir/home"

Currently, you can only reuse variables defined at the very top-level. Variables defined within context blocks of any kind cannot be reused.

raise_error

If set to 1, any type of error becomes fatal. Defaults to 0.

cmd_config(directive)

This is the meat-and-potatoes of the module; the method that lets you access configuration directives from your file. Examples:

my $server_name = $ac->cmd_config('ServerName');
my $doc_root = $ac->cmd_config('DocumentRoot');

This is a straightforward function. You just give it the name of the directive you wish to access and you get its value back. Multiple values are returned as a list, meaning that you can directly assign them to an array or even a hash (if the data structure is guaranteed to be consistent enough):

my @perlmods = $ac->cmd_config('PerlModule');
my %ftypes   = $ac->cmd_config('FileTypeSuffix');

cmd_context(context => specification)

You use this command to change the current context of what you are looking at. When you start, you are looking at the very top-level of the config file. However, you may want to look at a specific virtual host or directory. You can do so with this command.

my $vhost = $ac->cmd_context(VirtualHost => '10.1.1.2');
my $server_name = $vhost->cmd_config('ServerName');
my $doc_root    = $vhost->cmd_config('DocumentRoot');

You'll notice that the cmd_context() call returns an object will all the same methods, but the data structure now starts from that point down. The context has been altered so that you are looking at the VirtualHost 10.1.1.2. As such, any commands that you do will affect that part of the configuration.

In some cases, you may have multiple definitions for a certain context level. One example is VirtualHost blocks if you're using NameVirtualHosts. You have two options. First, you could cycle through all of them in sequence:

for my $vhost ($ac->cmd_context(VirtualHost => '10.1.1.2')) {
    # ... do stuff ...
}

Or, if you know which one you want specifically, you can specify one additional "search" parameter. For example, if you want the superfoo server, you could say:

my $sf = $ac->cmd_context(VirtualHost => '10.1.1.2',
                          ServerName  => 'superfoo');

And this would look for a context block that looked something like this:

<VirtualHost "10.1.1.2">
    ServerName "superfoo"
    # ... more config options ...
</VirtualHost>

You can access nested configurations as well. If you had a configuration like this:

<Location "/upload">
    SetHandler perl-script
    PerlHandler Apache::MyUploadModule
    PerlSetVar MyUploadModuleMaxsize "5M"
    PerlSetVar MyUploadModuleTimeout "300s"
    <Limit>
        require user "bob"
        require user "jim"
    </Limit>
</Location>

And you wanted to find out what the valid users were who could access this page, you would navigate it like so:

my $loc = $ac->cmd_context(Location => '/upload');
my $lim = $loc->cmd_context('Limit');
my @users = $lim->cmd_config('require');

Or, more succintly:

my @users = $ac->cmd_context(Location => '/upload')
               ->cmd_context('Limit')->cmd_config('require');

Since cmd_context() returns an object pointing to the next context, you can chain calls together to get to a deeply nested level.

dir_config()

This routine is provided for mod_perl compatibility. It allows you to access configuration commands specified via the PerlSetVar directive. So, assuming the above example, you could access the settings for MyUploadModule like so:

my $upload = $ac->cmd_context(Location => '/upload');

my $maxsize = $upload->dir_config('MyUploadModuleMaxsize');
my $timeout = $upload->dir_config('MyUploadModuleTimeout');

The idea is to provide an interface which walks and talks roughly like Apache actually would.

data()

This returns the entire data structure under the current context verabatim. So, you could get all the values for a VirtualHost with:

my $vh = $ac->cmd_context(VirtualHost => '10.1.1.4');
my %vhost = $vh->data;

If you specified ignore_case, then all the keys will be lowercase; otherwise, they will be in whatever case they are in the config file.

dump()

This returns a dump of the current data structure in string form. So for debugging purposes you can dump the config with something like this:

warn "DUMP: ", $ac->dump, "\n";

reread()

You can use this function to reread the configuration file. For example, maybe you want your application to reread its config if it receives a SIGHUP:

$SIG{HUP} = \&handler;
sub handler {
    my $sig = shift;
    if ($sig eq 'HUP') {
        # reread our config file on kill -HUP
        $config->reread;
    }
}

The above would handle a SIGHUP by rereading the config file.

write([file])

This writes the configuration out to disk. If no file is specified, then the one passed to read() is used. This method is currently under development and does not work. Patches welcome.

autoloaded calls

In addition to the above, you can also access values by calling a function named for the config command directly:

my $server_name = $ac->cmd_config('ServerName');

Is the same as:

my $server_name = $ac->server_name;

Underscores in the function name are taken as a place to put an uppercase letter. So these are all equivalent:

my $doc_root = $ac->cmd_config('DocumentRoot');
my $doc_root = $ac->DocumentRoot;   # looks silly
my $doc_root = $ac->document_root;

Note, though, that the following would not work unless you had set the ignore_case option:

my $doc_root = $ac->documentroot;   # won't work

This is because it will look for the directive Documentroot, which probably doesn't exist.

NOTES

Currently LogFormat and any other directive with embedded quotes, even if escaped, are not handled correctly. I know there is a fix for it but I have a mental block and can't figure it out. Help wanted.

This module does not mimic the behavior of a live Apache config. In particular, there is no configuration "inheritance". This means that subdirectories and virtual hosts do not inherit their defaults from the upper levels of the configuration. This may or may not change in a future version.

This module has only been tested and used on UNIX platforms. Patches to fix problems with other OSes are welcome.

There are currently no tests written for this module. Sorry, short on time. Inventive (or even non-inventive!) tests welcome.

VERSION

$Id: ConfigFile.pm,v 1.14 2001/09/06 23:57:54 nwiger Exp $

AUTHOR

This module is free software; you may copy this under the terms of the GNU General Public License, or the Artistic License, copies of which should have accompanied your Perl kit.

To install Apache::ConfigFile, copy and paste the appropriate command in to your terminal.

cpanm

cpanm Apache::ConfigFile

CPAN shell

perl -MCPAN -e shell
install Apache::ConfigFile

For more information on module installation, please visit the detailed CPAN module installation guide.

	Global
`s`	Focus search bar
`?`	Bring up this help dialog

	GitHub
`g` `p`	Go to pull requests
`g` `i`	go to github issues (only if github is preferred repository)

	POD
`g` `a`	Go to author
`g` `c`	Go to changes
`g` `i`	Go to issues
`g` `d`	Go to dist
`g` `r`	Go to repository/SCM
`g` `s`	Go to source
`g` `b`	Go to file browse

	Search terms
module: (e.g. module:Plugin)
distribution: (e.g. distribution:Dancer auth)
author: (e.g. author:SONGMU Redis)
version: (e.g. version:1.00)