# Config::General - phpMan

## NAME
    [Config::General] - Generic Config Module

## SYNOPSIS
     #
     # the OOP way
     use [Config::General];
     $conf = [Config::General]->new("rcfile");
     my %config = $conf->getall;

     #
     # the procedural way
     use [Config::General] qw(ParseConfig SaveConfig SaveConfigString);
     my %config = ParseConfig("rcfile");

## DESCRIPTION
    This module opens a config file and parses its contents for you. The new
    method requires one parameter which needs to be a filename. The method
    getall returns a hash which contains all options and its associated
    values of your config file.

    The format of config files supported by [Config::General] is inspired by
    the well known Apache config format, in fact, this module is 100%
    compatible to Apache configs, but you can also just use simple
    name/value pairs in your config files.

    In addition to the capabilities of an Apache config file it supports
    some enhancements such as here-documents, C-style comments or multiline
    options.

SUBROUTINES/METHODS
    new()
        Possible ways to call new():

         $conf = [Config::General]->new("rcfile");

         $conf = [Config::General]->new(\%somehash);

         $conf = [Config::General]->new( %options ); # see below for description of possible options

        This method returns a [Config::General] object (a hash blessed into
        "[Config::General]" namespace. All further methods must be used from
        that returned object. see below.

        You can use the new style with hash parameters or the old style
        which is of course still supported. Possible parameters to new()
        are:

        * a filename of a configfile, which will be opened and parsed by the
        parser

        or

        * a hash reference, which will be used as the config.

        An alternative way to call new() is supplying an option- hash with
        one or more of the following keys set:

        -ConfigFile
            A filename or a filehandle, i.e.:

             -ConfigFile => "rcfile" or -ConfigFile => \$FileHandle

        -ConfigHash
            A hash reference, which will be used as the config, i.e.:

             -ConfigHash => \%somehash

        -String
            A string which contains a whole config, or an arrayref
            containing the whole config line by line. The parser will parse
            the contents of the string instead of a file. i.e:

             -String => $complete_config

            it is also possible to feed an array reference to -String:

             -String => \@config_lines

        -AllowMultiOptions
            If the value is "no", then multiple identical options are
            disallowed. The default is "yes". i.e.:

             -AllowMultiOptions => "yes"

            see IDENTICAL OPTIONS for details.

        -LowerCaseNames
            If set to a true value, then all options found in the config
            will be converted to lowercase. This allows you to provide
            case-in-sensitive configs. The values of the options will not
            lowercased.

        -UseApacheInclude
            If set to a true value, the parser will consider "include ..."
            as valid include statement (just like the well known Apache
            include statement).

            It also supports apache's "IncludeOptional" statement with the
            same behavior, that is, if the include file doesn't exist no
            error will be thrown.

        -IncludeRelative
            If set to a true value, included files with a relative path
            (i.e. "cfg/blah.conf") will be opened from within the location
            of the configfile instead from within the location of the
            script($0). This works only if the configfile has a absolute
            pathname (i.e. "/etc/main.conf").

            If the variable -ConfigPath has been set and if the file to be
            included could not be found in the location relative to the
            current config file, the module will search within -ConfigPath
            for the file. See the description of -ConfigPath for more
            details.

        -IncludeDirectories
            If set to a true value, you may specify include a directory, in
            which case all files inside the directory will be loaded in
            ASCII order. Directory includes will not recurse into
            subdirectories. This is comparable to including a directory in
            Apache-style config files.

        -IncludeGlob
            If set to a true value, you may specify a glob pattern for an
            include to include all matching files (e.g. <<include
            conf.d/*.conf>>). Also note that as with standard file patterns,
            * will not match dot-files, so <<include dir/*>> is often more
            desirable than including a directory with -IncludeDirectories.

            An include option will not cause a parser error if the glob
            didn't return anything.

        -IncludeAgain
            If set to a true value, you will be able to include a
            sub-configfile multiple times. With the default, false, you will
            get a warning about duplicate includes and only the first
            include will succeed.

            Reincluding a configfile can be useful if it contains data that
            you want to be present in multiple places in the data tree. See
            the example under "INCLUDES".

            Note, however, that there is currently no check for include
            recursion.

        -ConfigPath
            As mentioned above, you can use this variable to specify a
            search path for relative config files which have to be included.
            [Config::General] will search within this path for the file if it
            cannot find the file at the location relative to the current
            config file.

            To provide multiple search paths you can specify an array
            reference for the path. For example:

             @path = qw(/usr/lib/perl /nfs/apps/lib /home/lib);
             ..
             -ConfigPath => \@path

        -MergeDuplicateBlocks
            If set to a true value, then duplicate blocks, that means blocks
            and named blocks, will be merged into a single one (see below
            for more details on this). The default behavior of
            [Config::General] is to create an array if some junk in a config
            appears more than once.

        -MergeDuplicateOptions
            If set to a true value, then duplicate options will be merged.
            That means, if the same option occurs more than once, the last
            one will be used in the resulting config hash.

            Setting this option implies -AllowMultiOptions == false unless
            you set -AllowMultiOptions explicit to 'true'. In this case
            duplicate blocks are allowed and put into an array but duplicate
            options will be merged.

        -AutoLaunder
            If set to a true value, then all values in your config file will
            be laundered to allow them to be used under a -T taint flag.
            This could be regarded as circumventing the purpose of the -T
            flag, however, if the bad guys can mess with your config file,
            you have problems that -T will not be able to stop. AutoLaunder
            will only handle a config file being read from -ConfigFile.

        -AutoTrue
            If set to a true value, then options in your config file, whose
            values are set to true or false values, will be normalised to 1
            or 0 respectively.

            The following values will be considered as true:

             yes, on, 1, true

            The following values will be considered as false:

             no, off, 0, false

            This effect is case-insensitive, i.e. both "Yes" or "No" will
            result in 1.

        -FlagBits
            This option takes one required parameter, which must be a hash
            reference.

            The supplied hash reference needs to define variables for which
            you want to preset values. Each variable you have defined in
            this hash-ref and which occurs in your config file, will cause
            this variable being set to the preset values to which the value
            in the config file refers to.

            Multiple flags can be used, separated by the pipe character |.

            Well, an example will clarify things:

             my $conf = [Config::General]->new(
                     -ConfigFile => "rcfile",
                     -FlagBits => {
                          Mode => {
                             CLEAR    => 1,
                             STRONG   => 1,
                             UNSECURE => "32bit" }
                     }
             );

            In this example we are defining a variable named *"Mode"* which
            may contain one or more of "CLEAR", "STRONG" and "UNSECURE" as
            value.

            The appropriate config entry may look like this:

             # rcfile
             Mode = CLEAR | UNSECURE

            The parser will create a hash which will be the value of the key
            "Mode". This hash will contain all flags which you have
            pre-defined, but only those which were set in the config will
            contain the pre-defined value, the other ones will be undefined.

            The resulting config structure would look like this after
            parsing:

             %config = (
                         Mode => {
                                   CLEAR    => 1,
                                   UNSECURE => "32bit",
                                   STRONG   => undef,
                                 }
                       );

            This method allows the user (or, the "maintainer" of the
            configfile for your application) to set multiple pre-defined
            values for one option.

            Please beware, that all occurrences of those variables will be
            handled this way, there is no way to distinguish between
            variables in different scopes. That means, if "Mode" would also
            occur inside a named block, it would also parsed this way.

            Values which are not defined in the hash-ref supplied to the
            parameter -FlagBits and used in the corresponding variable in
            the config will be ignored.

            Example:

             # rcfile
             Mode = BLAH | CLEAR

            would result in this hash structure:

              %config = (
                         Mode => {
                                   CLEAR    => 1,
                                   UNSECURE => undef,
                                   STRONG   => undef,
                                 }
                       );

            "BLAH" will be ignored silently.

        -DefaultConfig
            This can be a hash reference or a simple scalar (string) of a
            config. This causes the module to preset the resulting config
            hash with the given values, which allows you to set default
            values for particular config options directly.

            Note that you probably want to use this with
            -MergeDuplicateOptions, otherwise a default value already in the
            configuration file will produce an array of two values.

        -Tie
            -Tie takes the name of a Tie class as argument that each new
            hash should be based off of.

            This hash will be used as the 'backing hash' instead of a
            standard Perl hash, which allows you to affect the way, variable
            storing will be done. You could, for example supply a tied hash,
            say [Tie::DxHash], which preserves ordering of the keys in the
            config (which a standard Perl hash won't do). Or, you could
            supply a hash tied to a DBM file to save the parsed variables to
            disk.

            There are many more things to do in tie-land, see tie to get
            some interesting ideas.

            If you want to use the -Tie feature together with -DefaultConfig
            make sure that the hash supplied to -DefaultConfig must be tied
            to the same Tie class.

            Make sure that the hash which receives the generated hash
            structure (e.g. which you are using in the assignment: %hash =
            $config->getall()) must be tied to the same Tie class.

            Example:

             use [Config::General] qw(ParseConfig);
             use [Tie::IxHash];
             tie my %hash, "[Tie::IxHash]";
             %hash = ParseConfig(
                       -ConfigFile => shift(),
                       -Tie => "[Tie::IxHash]"
                     );

        -InterPolateVars
            If set to a true value, variable interpolation will be done on
            your config input. See [Config::General::Interpolated] for more
            information.

        -InterPolateEnv
            If set to a true value, environment variables can be used in
            configs.

            This implies -InterPolateVars.

        -AllowSingleQuoteInterpolation
            By default variables inside single quotes will not be
            interpolated. If you turn on this option, they will be
            interpolated as well.

        -ExtendedAccess
            If set to a true value, you can use object oriented (extended)
            methods to access the parsed config. See
            [Config::General::Extended] for more information.

        -StrictObjects
            By default this is turned on, which causes [Config::General] to
            croak with an error if you try to access a non-existent key
            using the OOP-way (-ExtendedAcess enabled). If you turn
            -StrictObjects off (by setting to 0 or "no") it will just return
            an empty object/hash/scalar. This is valid for OOP-access 8via
            AUTOLOAD and for the methods obj(), hash() and value().

        -StrictVars
            By default this is turned on, which causes [Config::General] to
            croak with an error if an undefined variable with
            InterPolateVars turned on occurs in a config. Set to *false*
            (i.e. 0) to avoid such error messages.

        -SplitPolicy
            You can influence the way how [Config::General] decides which part
            of a line in a config file is the key and which one is the
            value. By default it tries its best to guess. That means you can
            mix equalsign assignments and whitespace assignments.

            However, sometime you may wish to make it more strictly for some
            reason. In this case you can set -SplitPolicy. The possible
            values are: 'guess' which is the default, 'whitespace' which
            causes the module to split by whitespace, 'equalsign' which
            causes it to split strictly by equal sign, or 'custom'. In the
            latter case you must also set -SplitDelimiter to some regular
            expression of your choice. For example:

             -SplitDelimiter => '\s*:\s*'

            will cause the module to split by colon while whitespace which
            surrounds the delimiter will be removed.

            Please note that the delimiter used when saving a config
            (save_file() or save_string()) will be chosen according to the
            current -SplitPolicy. If -SplitPolicy is set to 'guess' or
            'whitespace', 3 spaces will be used to delimit saved options. If
            'custom' is set, then you need to set -StoreDelimiter.

        -SplitDelimiter
            Set this to any arbitrary regular expression which will be used
            for option/value splitting. -SplitPolicy must be set to 'custom'
            to make this work.

        -StoreDelimiter
            You can use this parameter to specify a custom delimiter to use
            when saving configs to a file or string. You only need to set it
            if you want to store the config back to disk and if you have
            -SplitPolicy set to 'custom'.

            However, this parameter takes precedence over whatever is set
            for -SplitPolicy.

            Be very careful with this parameter.

        -CComments
            [Config::General] is able to notice c-style comments (see section
            COMMENTS). But for some reason you might no need this. In this
            case you can turn this feature off by setting -CComments to a
            false value('no', 0, 'off').

            By default -CComments is turned on.

        -BackslashEscape
            Deprecated Option.

        -SlashIsDirectory
            If you turn on this parameter, a single slash as the last
            character of a named block will be considered as a directory
            name.

            By default this flag is turned off, which makes the module
            somewhat incompatible to Apache configs, since such a setup will
            be normally considered as an explicit empty block, just as XML
            defines it.

            For example, if you have the following config:

             <Directory />
               Index index.awk
             </Directory>

            you will get such an error message from the parser:

             EndBlock "</Directory>" has no StartBlock statement (level: 1, chunk 10)!

            This is caused by the fact that the config chunk below will be
            internally converted to:

             <Directory></Directory>
               Index index.awk
             </Directory>

            Now there is one '</Directory>' too much. The proper solution is
            to use quotation to circumvent this error:

             <Directory "/">
               Index index.awk
             </Directory>

            However, a raw apache config comes without such quotes. In this
            case you may consider to turn on -SlashIsDirectory.

            Please note that this is a new option (incorporated in version
            2.30), it may lead to various unexpected side effects or other
            failures. You've been warned.

        -UseApacheIfDefine
            Enables support for Apache <IfDefine> ... </IfDefine>. See
            -Define.

        -Define
            Defines the symbols to be used for conditional configuration
            files. Allowed arguments: scalar, scalar ref, array ref or hash
            ref.

            Examples:

             -Define => 'TEST'
             -Define => \$testOrProduction
             -Define => [qw(TEST VERBOSE)]
             -Define => {TEST => 1, VERBOSE => 1}

            Sample configuration:

              <Logging>
                <IfDefine TEST>
                   Level Debug
                   include test/*.cfg
                </IfDef>
                <IfDefine !TEST>
                  Level Notice
                   include production/*.cfg
                </IfDefine>
              </Logging>

        -ApacheCompatible
            Over the past years a lot of options has been incorporated into
            [Config::General] to be able to parse real Apache configs.

            The new -ApacheCompatible option now makes it possible to tweak
            all options in a way that Apache configs can be parsed.

            This is called "apache compatibility mode" - if you will ever
            have problems with parsing Apache configs without this option
            being set, you'll get no help by me. Thanks :)

            The following options will be set:

             UseApacheInclude   = 1
             IncludeRelative    = 1
             IncludeDirectories = 1
             IncludeGlob        = 1
             SlashIsDirectory   = 1
             SplitPolicy        = 'whitespace'
             CComments          = 0
             UseApacheIfDefine  = 1

            Take a look into the particular documentation sections what
            those options are doing.

            Beside setting some options it also turns off support for
            explicit empty blocks.

        -UTF8
            If turned on, all files will be opened in utf8 mode. This may
            not work properly with older versions of Perl.

        -SaveSorted
            If you want to save configs in a sorted manner, turn this
            parameter on. It is not enabled by default.

        -NoEscape
            If you want to use the data ( scalar or final leaf ) without
            escaping special character, turn this parameter on. It is not
            enabled by default.

        -NormalizeBlock
            Takes a subroutine reference as parameter and gets the current
            block or blockname passed as parameter and is expected to return
            it in some altered way as a scalar string. The sub will be
            called before anything else will be done by the module itself
            (e.g. interpolation).

            Example:

             -NormalizeBlock => sub { my $x = shift; $x =~ s/\s*$//; $x; }

            This removes trailing whitespaces of block names.

        -NormalizeOption
            Same as -NormalizeBlock but applied on options only.

        -NormalizeValue
            Same as -NormalizeBlock but applied on values only.

    getall()
        Returns a hash structure which represents the whole config.

    files()
        Returns a list of all files read in.

    save_file()
        Writes the config hash back to the hard disk. This method takes one
        or two parameters. The first parameter must be the filename where
        the config should be written to. The second parameter is optional,
        it must be a reference to a hash structure, if you set it. If you do
        not supply this second parameter then the internal config hash,
        which has already been parsed, will be used.

        Please note that any occurrence of comments will be ignored by
        getall() and thus be lost after you call this method.

        You need also to know that named blocks will be converted to nested
        blocks (which is the same from the perl point of view). An example:

         <user hans>
           id 13
         </user>

        will become the following after saving:

         <user>
           <hans>
              id 13
           </hans>
         </user>

        Example:

         $conf_obj->save_file("newrcfile", \%config);

        or, if the config has already been parsed, or if it didn't change:

         $conf_obj->save_file("newrcfile");

    save_string()
        This method is equivalent to the previous save_file(), but it does
        not store the generated config to a file. Instead it returns it as a
        string, which you can save yourself afterwards.

        It takes one optional parameter, which must be a reference to a hash
        structure. If you omit this parameter, the internal config hash,
        which has already been parsed, will be used.

        Example:

         my $content = $conf_obj->save_string(\%config);

        or:

         my $content = $conf_obj->save_string();

## CONFIG FILE FORMAT
    Lines beginning with # and empty lines will be ignored. (see section
    COMMENTS!) Spaces at the beginning and the end of a line will also be
    ignored as well as tabulators. If you need spaces at the end or the
    beginning of a value you can surround it with double quotes. An option
    line starts with its name followed by a value. An equal sign is
    optional. Some possible examples:

     user    max
     user  = max
     user            max

    If there are more than one statements with the same name, it will create
    an array instead of a scalar. See the example below.

    The method getall returns a hash of all values.

## BLOCKS
    You can define a block of options. A block looks much like a block in
    the wellknown Apache config format. It starts with <blockname> and ends
    with </blockname>.

    A block start and end cannot be on the same line.

    An example:

     <database>
      host   = muli
      user   = moare
      dbname = modb
      dbpass = D4r_9Iu
     </database>

    Blocks can also be nested. Here is a more complicated example:

     user   = hans
     server = mc200
     db     = maxis
     passwd = D3rf$
     <jonas>
      user    = tom
      db      = unknown
      host    = mila
      <tablestructure>
       index   [int(100000)]
       name    [char(100)]
       prename [char(100)]
       city    [char(100)]
       status  [int(10)]
       allowed moses
       allowed ingram
       allowed joice
      </tablestructure>
     </jonas>

    The hash which the method getall returns look like that:

      print [Data::Dumper](\%hash);
      $VAR1 = {
               'passwd' => 'D3rf$',
               'jonas'  => {
                            'tablestructure' => {
                                                 'prename' => '[char(100)]',
                                                 'index'   => '[int(100000)]',
                                                 'city'    => '[char(100)]',
                                                 'name'    => '[char(100)]',
                                                 'status'  => '[int(10)]',
                                                 'allowed' => [
                                                               'moses',
                                                               'ingram',
                                                               'joice',
                                                              ]
                                                },
                            'host'           => 'mila',
                            'db'             => 'unknown',
                            'user'           => 'tom'
                           },
               'db'     => 'maxis',
               'server' => 'mc200',
               'user'   => 'hans'
              };

    If you have turned on -LowerCaseNames (see new()) then blocks as in the
    following example:

     <Dir>
      <AttriBUTES>
       Owner  root
      </attributes>
     </dir>

    would produce the following hash structure:

      $VAR1 = {
               'dir' => {
                         'attributes' => {
                                          'owner'  => "root",
                                         }
                        }
              };

    As you can see, the keys inside the config hash are normalized.

    Please note, that the above config block would result in a valid hash
    structure, even if -LowerCaseNames is not set! This is because
    *[Config::General]* does not use the block names to check if a block ends,
    instead it uses an internal state counter, which indicates a block end.

    If the module cannot find an end-block statement, then this block will
    be ignored.

## NAMED BLOCKS
    If you need multiple blocks of the same name, then you have to name
    every block. This works much like Apache config. If the module finds a
    named block, it will create a hashref with the left part of the named
    block as the key containing one or more hashrefs with the right part of
    the block as key containing everything inside the block(which may again
    be nested!). As examples says more than words:

    # given the following sample <Directory /usr/frisco> Limit Deny Options
    ExecCgi Index </Directory> <Directory /usr/frik> Limit DenyAll Options
    None </Directory>

    # you will get:

      $VAR1 = {
               'Directory' => {
                               '/usr/frik' => {
                                               'Options' => 'None',
                                               'Limit' => 'DenyAll'
                                              },
                               '/usr/frisco' => {
                                                 'Options' => 'ExecCgi Index',
                                                 'Limit' => 'Deny'
                                                }
                              }
              };

    You cannot have more than one named block with the same name because it
    will be stored in a hashref and therefore be overwritten if a block
    occurs once more.

## WHITESPACE IN BLOCKS
    The normal behavior of [Config::General] is to look for whitespace in
    block names to decide if it's a named block or just a simple block.

    Sometimes you may need blocknames which have whitespace in their names.

    With named blocks this is no problem, as the module only looks for the
    first whitespace:

     <person hugo gera>
     </person>

    would be parsed to:

      $VAR1 = {
               'person' => {
                            'hugo gera' => {
                                           },
                           }
              };

    The problem occurs, if you want to have a simple block containing
    whitespace:

     <hugo gera>
     </hugo gera>

    This would be parsed as a named block, which is not what you wanted. In
    this very case you may use quotation marks to indicate that it is not a
    named block:

     <"hugo gera">
     </"hugo gera">

    The save() method of the module inserts automatically quotation marks in
    such cases.

## EXPLICIT EMPTY BLOCKS
    Beside the notation of blocks mentioned above it is possible to use
    explicit empty blocks.

    Normally you would write this in your config to define an empty block:

     <driver Apache>
     </driver>

    To save writing you can also write:

     <driver Apache/>

    which is the very same as above. This works for normal blocks and for
    named blocks.

IDENTICAL OPTIONS (ARRAYS)
    You may have more than one line of the same option with different
    values. Example:

     log  log1
     log  log2
     log  log2

    You will get a scalar if the option occurred only once or an array if it
    occurred more than once. If you expect multiple identical options, then
    you may need to check if an option occurred more than once:

      $allowed = $hash{jonas}->{tablestructure}->{allowed};
      if (ref($allowed) eq "ARRAY") {
        @ALLOWED = @{$allowed};
        else {
          @ALLOWED = ($allowed);
        }
      }

    The same applies to blocks and named blocks too (they are described in
    more detail below). For example, if you have the following config:

     <dir blah>
      user max
     </dir>
     <dir blah>
      user hannes
     </dir>

    then you would end up with a data structure like this:

      $VAR1 = {
               'dir' => {
                         'blah' => [
                                    {
                                     'user' => 'max'
                                    },
                                    {
                                     'user' => 'hannes'
                                    }
                                   ]
                        }
              };

    As you can see, the two identical blocks are stored in a hash which
    contains an array(-reference) of hashes.

    Under some rare conditions you might not want this behavior with blocks
    (and named blocks too). If you want to get one single hash with the
    contents of both identical blocks, then you need to turn the new()
    parameter -MergeDuplicateBlocks on (see above). The parsed structure of
    the example above would then look like this:

      $VAR1 = {
               'dir' => {
                         'blah' => {
                                    'user' => [
                                               'max',
                                               'hannes'
                                              ]
                                   }
                        }
              };

    As you can see, there is only one hash "dir->{blah}" containing multiple
    "user" entries. As you can also see, turning on -MergeDuplicateBlocks
    does not affect scalar options (i.e. "option = value"). In fact you can
    tune merging of duplicate blocks and options independent from each
    other.

    If you don't want to allow more than one identical options, you may turn
    it off by setting the flag *AllowMultiOptions* in the new() method to
    "no". If turned off, [Config::General] will complain about multiple
    occurring options with identical names!

  FORCE SINGLE VALUE ARRAYS
    You may also force a single config line to get parsed into an array by
    turning on the option -ForceArray and by surrounding the value of the
    config entry by []. Example:

     hostlist = [ foo.bar ]

    Will be a singlevalue array entry if the option is turned on. If you
    want it to remain to be an array you have to turn on -ForceArray during
    save too.

## LONG LINES
    If you have a config value, which is too long and would take more than
    one line, you can break it into multiple lines by using the backslash
    character at the end of the line. The [Config::General] module will
    concatenate those lines to one single-value.

    Example:

     command = cat /var/log/secure/tripwire | \
     mail C<-s> "report from tripwire" \
     <honey@myotherhost.nl>

    command will become: "cat /var/log/secure/tripwire | mail "-s" 'report
    from twire' <honey@myotherhost.nl>"

## HERE DOCUMENTS
    You can also define a config value as a so called "here-document". You
    must tell the module an identifier which indicates the end of a here
    document. An identifier must follow a "<<".

    Example:

     message <<EOF
      we want to
      remove the
      homedir of
      root.
     EOF

    Everything between the two "EOF" strings will be in the option
    *message*.

    There is a special feature which allows you to use indentation with here
    documents. You can have any amount of whitespace or tabulators in front
    of the end identifier. If the module finds spaces or tabs then it will
    remove exactly those amount of spaces from every line inside the
    here-document.

    Example:

     message <<EOF
        we want to
        remove the
        homedir of
        root.
        EOF

    After parsing, message will become:

     we want to
     remove the
     homedir of
     root.

    because there were the string " " in front of EOF, which were cut from
    every line inside the here-document.

## INCLUDES
    You can include an external file at any position in your config file
    using the following statement in your config file:

     <<include externalconfig.rc>>

    If you turned on -UseApacheInclude (see new()), then you can also use
    the following statement to include an external file:

     include externalconfig.rc

    This file will be inserted at the position where it was found as if the
    contents of this file were directly at this position.

    You can also recursively include files, so an included file may include
    another one and so on. Beware that you do not recursively load the same
    file, you will end with an error message like "too many open files in
    system!".

    By default included files with a relative pathname will be opened from
    within the current working directory. Under some circumstances it maybe
    possible to open included files from the directory, where the configfile
    resides. You need to turn on the option -IncludeRelative (see new()) if
    you want that. An example:

     my $conf = [Config::General](
      -ConfigFile => "/etc/crypt.d/server.cfg"
      -IncludeRelative => 1
     );

    /etc/crypt.d/server.cfg:

     <<include acl.cfg>>

    In this example [Config::General] will try to include *acl.cfg* from
    */etc/crypt.d*:

     /etc/crypt.d/acl.cfg

    The default behavior (if -IncludeRelative is not set!) will be to open
    just *acl.cfg*, wherever it is, i.e. if you did a
    chdir("/usr/local/etc"), then [Config::General] will include:

     /usr/local/etc/acl.cfg

    Include statements can be case insensitive (added in version 1.25).

    Include statements will be ignored within C-Comments and here-documents.

    By default, a config file will only be included the first time it is
    referenced. If you wish to include a file in multiple places, set
    /-IncludeAgain to true. But be warned: this may lead to infinite loops,
    so make sure, you're not including the same file from within itself!

    Example:

     # main.cfg
     <object billy>
      class=[Some::Class]
     <printers>
      include printers.cfg
     </printers>
     # ...
     </object>
      <object bob>
       class=[Another::Class]
      <printers>
      include printers.cfg
      </printers>
      # ...
     </object>

    Now "printers.cfg" will be include in both the "billy" and "bob"
    objects.

    You will have to be careful to not recursively include a file. Behaviour
    in this case is undefined.

## COMMENTS
    A comment starts with the number sign #, there can be any number of
    spaces and/or tab stops in front of the #.

    A comment can also occur after a config statement. Example:

     username = max  # this is the comment

    If you want to comment out a large block you can use C-style comments. A
    /* signals the begin of a comment block and the */ signals the end of
    the comment block. Example:

     user  = max # valid option
     db    = tothemax
     /*
     user  = andors
     db    = toand
     */

    In this example the second options of user and db will be ignored.
    Please beware of the fact, if the Module finds a /* string which is the
    start of a comment block, but no matching end block, it will ignore the
    whole rest of the config file!

    NOTE: If you require the # character (number sign) to remain in the
    option value, then you can use a backslash in front of it, to escape it.
    Example:

     bgcolor = \#ffffcc

    In this example the value of $config{bgcolor} will be "#ffffcc",
    [Config::General] will not treat the number sign as the begin of a comment
    because of the leading backslash.

    Inside here-documents escaping of number signs is NOT required!

## PARSER PLUGINS
    You can alter the behavior of the parser by supplying closures which
    will be called on certain hooks during config file processing and
    parsing.

    The general aproach works like this:

      sub ck {
        my($file, $base) = @_;
        print "_open() tries $file ... ";
        if ($file =~ /blah/) {
          print "ignored\n";
          return (0);
        } else {
          print "allowed\n";
          return (1, @_);
        }
      }

      my %c = ParseConfig(
                          -IncludeGlob      => 1,
                          -UseApacheInclude => 1,
                          -ConfigFile       => shift,
                          -Plug             => { pre_open => *ck }
                         );

    Output:

     _open() tries cfg ... allowed
     _open() tries x/*.conf ... allowed
     _open() tries x/1.conf ... allowed
     _open() tries x/2.conf ... allowed
     _open() tries x/blah.conf ... ignored

    As you can see, we wrote a little sub which takes a filename and a base
    directory as parameters. We tell [Config::General] via the Plug parameter
    of new() to call this sub everytime before it attempts to open a file.

    General processing continues as usual if the first value of the returned
    array is true. The second value of that array depends on the kind of
    hook being called.

    The following hooks are available so far:

    pre_open
        Takes two parameters: filename and basedirectory.

        Has to return an array consisting of 3 values:

         - 1 or 0 (continue processing or not)
         - filename
         - base directory

    pre_read
        Takes two parameters: the filehandle of the file to be read and an
        array containing the raw contents of said file.

        This hook will be applied in _read(). File contents are already
        available at this stage, comments will be removed, here-docs
        normalized and the like. This hook gets the unaltered, original
        contents.

        Has to return an array of 3 values:

         - 1 or 0 (continue processing or not)
         - the filehandle
         - an array of strings

        You can use this hook to apply your own normalizations or whatever.

        Be careful when returning the abort value (1st value of returned
        array 0), since in this case nothing else would be done on the
        contents. If it still contains comments or something, they will be
        parsed as legal config options.

    post_read
        Takes one parameter: a reference to an array containing the prepared
        config lines (after being processed by _read()).

        This hook will be applied in _read() when everything else has been
        done.

        Has to return an array of 2 values:

         - 1 or 0 (continue processing or not) [Ignored for post hooks]
         - a reference to an array containing the config lines

    pre_parse_value
        Takes 2 parameters: an option name and its value.

        This hook will be applied in _parse_value() before any processing.

        Has to return an array of 3 values:

         - 1 or 0 (continue processing or not)
         - option name
         - value of the option

    post_parse_value
        Almost identical to pre_parse_value, but will be applied after
        _parse_value() is finished and all usual processing and
        normalization is done.

    Not implemented yet: hooks for variable interpolation and block parsing.

## OBJECT ORIENTED INTERFACE
    There is a way to access a parsed config the OO-way. Use the module
    [Config::General::Extended], which is supplied with the [Config::General]
    distribution.

## VARIABLE INTERPOLATION
    You can use variables inside your config files if you like. To do that
    you have to use the module [Config::General::Interpolated], which is
    supplied with the [Config::General] distribution.

## EXPORTED FUNCTIONS
    [Config::General] exports some functions too, which makes it somewhat
    easier to use it, if you like this.

    How to import the functions:

     use [Config::General] qw(ParseConfig SaveConfig SaveConfigString);

    ParseConfig()
        This function takes exactly all those parameters, which are allowed
        to the new() method of the standard interface.

        Example:

         use [Config::General] qw(ParseConfig);
         my %config = ParseConfig(-ConfigFile => "rcfile", -AutoTrue => 1);

    SaveConfig()
        This function requires two arguments, a filename and a reference to
        a hash structure.

        Example:

         use [Config::General] qw(SaveConfig);
         ..
         SaveConfig("rcfile", \%some_hash);

    SaveConfigString()
        This function requires a reference to a config hash as parameter. It
        generates a configuration based on this hash as the object-interface
        method save_string() does.

        Example:

         use [Config::General] qw(ParseConfig SaveConfigString);
         my %config = ParseConfig(-ConfigFile => "rcfile");
         .. # change %config something
         my $content = SaveConfigString(\%config);

## CONFIGURATION AND ENVIRONMENT
    No environment variables will be used.

## SEE ALSO
    I recommend you to read the following documents, which are supplied with
    Perl:

     perlreftut                     Perl references short introduction
     perlref                        Perl references, the rest of the story
     perldsc                        Perl data structures intro
     perllol                        Perl data structures: arrays of arrays

     [Config::General::Extended]      Object oriented interface to parsed configs
     [Config::General::Interpolated]  Allows one to use variables inside config files

## LICENSE AND COPYRIGHT
    Copyright (c) 2000-2016 Thomas Linden

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

## BUGS AND LIMITATIONS
    See rt.cpan.org for current bugs, if any.

## INCOMPATIBILITIES
    None known.

## DIAGNOSTICS
    To debug [Config::General] use the Perl debugger, see perldebug.

## DEPENDENCIES
    [Config::General] depends on the modules FileHandle,
    [File::Spec::Functions], [File::Glob], which all are shipped with Perl.

## AUTHOR
    Thomas Linden <tlinden |AT| cpan.org>

## VERSION
    2.63

