NAME
    Config::IniFiles - A module for reading .ini-style configuration files.

         $Header: /cvsroot/config-inifiles/config-inifiles/README,v 1.2 2000/11/24 20:40:58 rbowen Exp $

SYNOPSIS
      use Config::IniFiles;
      my $cfg = new Config::IniFiles( -file => "/path/configfile.ini" );
      print "We have parm $cfg->val( 'Section', 'Parameter' )." if $cfg->val( 'Section', 'Parameter' );

DESCRIPTION
    Config::IniFiles provides a way to have readable configuration files
    outside your Perl script. The configuration can be safely reloaded upon
    receipt of a signal. Configurations can be imported (inherited,
    stacked,...), sections can be grouped, and settings can be accessed from
    a tied hash.

USAGE -- Object Interface
    Get a new Config::IniFiles object with the *new* method:

      $cfg = Config::IniFiles->new( -file => "/path/configfile.ini" );
      $cfg = new Config::IniFiles -file => "/path/configfile.ini";

    Optional named parameters may be specified after the configuration file
    name. See the *new* in the METHODS section, below.

    INI files consist of a number of sections, each preceeded with the
    section name in square brackets. The first nonblank character of the
    line indicating a section must be a left bracket and the last nonblank
    character of a line indicating a section must be a right bracket. The
    characters making up the section name can be any symbols at all. The
    section may even be be empty. However section names must be unique.

    Parameters are specified in each section as Name=Value. Any spaces
    around the equals sign will be ignored, and the value extends to the end
    of the line. Parameter names are localized to the namespace of the
    section, but must be unique within a section.

      [section]
      Parameter=Value

    Both the hash mark (#) and the semicolon (;) are comment characters.
    Lines that begin with either of these characters will be ignored. Any
    amount of whitespace may preceed the comment character.

    Multiline or multivalued fields may also be defined ala UNIX "here
    document" syntax:

      Parameter=<<EOT
      value/line 1
      value/line 2
      EOT

    You may use any string you want in place of "EOT". Note that what
    follows the "<<" and what appears at the end of the text MUST match
    exactly, including any trailing whitespace.

    See the METHODS section, below, for settable options.

    Values from the config file are fetched with the val method:

      $value = $cfg->val('Section', 'Parameter');

    If you want a multi-line/value field returned as an array, just specify
    an array as the receiver:

      @values = $cfg->val('Section', 'Parameter');

METHODS
  new ( [-option=>value ...] )

    Returns a new configuration object (or "undef" if the configuration file
    has an error). One Config::IniFiles object is required per configuration
    file. The following named parameters are available:

    *-file* filename
              Specifies a file to load the parameters from. If this option
              is not specified, (ie: you are creating a config file from
              scratch) you must specify a target file using SetFileName in
              order to save the parameters.

    *-default* section
              Specifies a section is used for default values. For example,
              if you look up the "permissions" parameter in the "users"
              section, but there is none, Config::IniFiles will look to your
              default section for a "permissions" value before returning
              undef.

    *-reloadwarn* 0|1
              Set -reloadwarn => 1 to enable a warning message (output to
              STDERR) whenever the config file is reloaded. The reload
              message is of the form:

                PID <PID> reloading config file <file> at YYYY.MM.DD HH:MM:SS

              See your system documentation for information on valid
              signals.

    *-nocase* 0|1
              Set -nocase => 1 to handle the config file in a
              case-insensitive manner (case in values is preserved,
              however). By default, config files are case-sensitive (i.e., a
              section named 'Test' is not the same as a section named
              'test'). Note that there is an added overhead for turning off
              case sensitivity.

    *-import* object
              This allows you to import or inherit existing setting from
              another Config::IniFiles object. When importing settings from
              another object, sections with the same name will be merged and
              parameters that are defined in both the imported object and
              the *-file* will take the value of given in the *-file*.

              If a *-default* section is also given on this call, and it
              does not coincide with the default of the imported object, the
              new default section will be used instead. If no *-default*
              section is given, then the default of the imported object will
              be used.

  val ($section, $parameter)

    Returns the value of the specified parameter in section $section,
    returns undef if no section or no parameter for the given section
    exists.

    If you want a multi-line/value field returned as an array, just specify
    an array as the receiver:

      @values = $cfg->val('Section', 'Parameter');

  setval ($section, $parameter, $value, [ $value2, ... ])

    Sets the value of parameter $parameter in section $section to $value (or
    to a set of values). See below for methods to write the new
    configuration back out to a file.

    You may not set a parameter that didn't exist in the original
    configuration file. setval will return *undef* if this is attempted. See
    newval below to do this. Otherwise, it returns 1.

  newval($setion, $parameter, $value [, $value2, ...])

    Adds a new value to the configuration file.

  delval($section, $parameter)

    Deletes the specified value from the configuration file

  ReadConfig

    Forces the config file to be re-read. Also see the *-reloadsig* option
    to the new method for a way to connect this method to a signal (such as
    SIGHUP). Returns undef if the file can not be opened.

  Sections

    Returns an array containing section names in the configuration file. If
    the *nocase* option was turned on when the config object was created,
    the section names will be returned in lowercase.

  Parameters ($sectionname)

    Returns an array containing the parameters contained in the specified
    section.

  Groups

    Returns an array containing the names of available groups.

    Groups are specified in the config file as new sections of the form

      [GroupName MemberName]

    This is useful for building up lists. Note that parameters within a
    "member" section are referenced normally (i.e., the section name is
    still "Groupname Membername", including the space).

  GroupMembers ($group)

    Returns an array containing the members of specified $group.

  WriteConfig ($filename)

    Writes out a new copy of the configuration file. A temporary file
    (ending in .new) is written out and then renamed to the specified
    filename. Also see BUGS below.

  RewriteConfig

    Same as WriteConfig, but specifies that the original configuration file
    should be rewritten.

  SetFileName ($filename)

    If you created the Config::IniFiles object without initialising from a
    file, or if you just want to change the name of the file to use for
    ReadConfig/RewriteConfig from now on, use this method.

    Returns $filename if that was a valid name, undef otherwise.

  SetSectionComment($section, @comment)

    Sets the comment for section $section to the lines contained in
    @comment. Each comment line will be prepended with "#" if it doesn't
    already have a comment character (ie: if $line !~ m/^\s*[#;]/)

    To clear a section comment, use DeleteSectionComment ($section)

  GetSectionComment ($section)

    Returns a list of lines, being the comment attached to section $section.
    In scalar context, returns a string containing the lines of the comment
    separated by newlines.

    The lines are presented as-is, with whatever comment character was
    originally used on that line.

  DeleteSectionComment ($section)

    Removes the comment for the specified section.

  SetParameterComment ($section, $parameter, @comment)

    Sets the comment attached to a particular parameter.

    Any line of @comment that does not have a comment character will be
    prepended with "#".

  GetParameterEOT ($section, $parameter)

    Accessor method for the EOT text (in fact, style) of the specified
    parameter. If any text is used as an EOT mark, this will be returned. If
    the parameter was not recorded using HERE style multiple lines,
    GetParameterEOT returns undef.

  SetParameterEOT ($section, $EOT)

    Accessor method for the EOT text for the specified parameter. Sets the
    HERE style marker text to the value $EOT. Once the EOT text is set, that
    parameter will be saved in HERE style.

    To un-set the EOT text, use DeleteParameterEOT ($section, $parameter).

  DeleteParameterEOT ($section, $parameter)

USAGE -- Tied Hash
  tie $ini, 'Config::Inifiles', (-file=>$filename, [-option=>value ...] )

    Using 'tie', you can tie a hash to a Config::IniFiles object. This
    creates a new object which you can access through your hash, so you use
    this instead of the new method. This actually creates a hash of hashes
    to access the values in the .ini-file.

    Here's an example:

      use Config::IniFiles;
  
      my %ini
      tie %ini, 'Config::IniFiles', ( -file => "/path/configfile.ini" );

      print "We have parm %ini{Section}{Parameter}." if %ini{'Section'}{'Parameter'};

    Accessing and using the hash works just like accessing and using an
    object, except in the way you reference it. More information about using
    the hash interface is descibed below under the corresponding object
    methods.

    For those methods that do not coincide with the hash paradigm, you can
    use the Perl 'tied' function to get at the underlying object tied to the
    hash and call methods on that object. For example, to write the hash out
    to a new ini file, you would do something like this:

      tied( %ini )->WriteConfig( "/newpath/newconfig.ini" ) ||
        die "Could not write settings to new file.";

  $val = $ini{$section}{$parameter}

    Returns the value of $parameter in $section, through the hash tie
    interface.

    Because of limitations in Perl's tie implementation, multiline values
    accessed through a hash will always be returned as a single value with
    each line joined by the default line separator ($\). To break them apart
    you can simple do this:

      @lines = split( "$\", $ini{section}{multi_line_parameter} );

  $ini{$section}{$parameter} = $value;

    Sets the value of $parameter in $section to value given. through the
    hash interface. If the parameter did not exist in the original file, it
    will be created.

    To set a multiline or multivalue parameter use something like this:

     $ini{$section}{$parameter} = [$value1, $value2, ...];

    However, Perl does not seem to extend autovivification to tied hashes.
    That means that if you try to say

      $ini{new_section}{new_paramters} = $val;

    and the section 'new_section' does not exist, then Perl won't properly
    create it. In order to work around this you will need to create a hash
    reference in that section and then assign the parameter value. Something
    like this should do nicely:

      $ini{new_section} = {};
      $ini{new_section}{new_paramters} = $val;

  %hash = %{$ini{$section}}

    Using the tie interface, you can copy whole sections of the ini file
    into another hash. Note that this makes a copy of the entire section.
    The new hash in no longer tied to the ini file, In particular, this
    means -default and -nocase settings will not apply to '%hash'.

  $ini{$section} = {}; %{$ini{$section}} = %parameters;

    Through the hash interface, you have the ability to replace the entire
    section with a new set of parameters. This call will fail, however, if
    the argument passed in NOT a hash reference. You must use both lines, as
    shown above so that Perl recognizes the section as a hash reference
    context before COPYing over the values from your '%parameters' hash.

  delete $ini{$section}{$parameter}

    When tied to a hash, you can use the Perl 'delete' function to
    completely remove a parameter from a section.

  delete $ini{$section}

    The tied interface also allows you to delete an entire section from the
    ini file using the Perl 'delete' function.

  $ini = ();

    If you really want to delete all the items in the ini file, this will do
    it. Of course, the changes won't be written to the actual file unless
    you call RewriteConfig on the object tied to the hash.

  Parameter names

    my @keys = keys %{$ini{$section}}
    while (($k, $v) = each %{$ini{$section}}) {...}
    if( exists %{$ini{$section}}, $parameter ) {...}
    When tied to a hash, you use the Perl 'keys' and 'each' functions to
    iteratively list the parameters ('keys') or parameters and their values
    ('each') in a given section.

    You can also use the Perl 'exists' function to see if a parameter is
    defined in a given section.

    Note that none of these will return parameter names that are part if the
    default section (if set), although accessing and unknown parameter in
    the specified section will return a value from the default section if
    there is one.

  Section names

    keys %ini, $section
    while (($k, $v) = each %ini) {...}
    if( exists %ini, $section ) {...}
    When tied to a hash, you use the Perl 'keys' and 'each' functions to
    iteratively list the sections in the ini file.

    You can also use the Perl 'exists' function to see if a section is
    defined in the file.

DIAGNOSTICS
  @Config::IniFiles::errors

    Contains a list of errors encountered while parsing the configuration
    file. If the *new* method returns undef, check the value of this to find
    out what's wrong. This value is reset each time a config file is read.

BUGS
    *  The output from [Re]WriteConfig/OutputConfig might not be as pretty
       as it can be. Comments are tied to whatever was immediately below
       them.

    *  No locking is done by [Re]WriteConfig. When writing servers, take
       care that only the parent ever calls this, and consider making your
       own backup.

Data Structure
    Note that this is only a reference for the package maintainers - one of
    the upcoming revisions to this package will include a total clean up of
    the data structure.

      $iniconf->{cf} = "config_file_name"
              ->{startup_settings} = \%orginal_object_parameters
              ->{firstload} = 0
              ->{nocase} = 0
              ->{reloadwarn} = 0
              ->{sects} = \@sections
              ->{sCMT}{$section} = \@comment_lines
              ->{group}{$group} = \@group_members
              ->{parms}{$section} = \@section_parms
              ->{EOT}{$sect}{$parm} = "end of text string"
              ->{pCMT}{$section}{$parm} = \@comment_lines
              ->{v}{$section}{$parm} = $value   OR  \@values

AUTHOR and ACKNOWLEDGEMENTS
    The original code was written by Scott Hutton. It has since been taken
    over by Rich Bowen, with many contributions from various other people.

    In particular, special thanks go to (in roughly chronological order):

    Bernie Cosell, Alan Young, Alex Satrapa, Mike Blazer, Wilbert van de
    Pieterman, Steve Campbell, Robert Konigsberg, Scott Dellinger, R.
    Bernstein, Jeremy Wadsack, Daniel Winkelmann, Pires Claudio, and Adrian
    Phillips.

    Geez, that's a lot of people. And apologies to the folks I missed.

    If you want someone to bug about this, that would be:

            Rich Bowen <rbowen at rcbowen dot com>

    If you want more information, or want to participate, go to:

            http://sourceforge.net/projects/config-inifiles/

    Please send bug reports to config-inifiles-bugs@lists.sourceforge.net

    Development discussion occurs on the mailing list
    config-inifiles-dev@lists.sourceforge.net, which you can subscribe to by
    going to the project web site (link above).

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

Change log
         $Log: README,v $
         Revision 1.2  2000/11/24 20:40:58  rbowen
         Updated MANIFEST to have file list of new files in t/
         Updated IniFiles.pm to have mention of sourceforge addresses, rather than rcbowen.com addresses
         Regenerated README from IniFiles.pm

         Revision 1.9  2000/11/23 05:08:08  grail
         Fixed documentation for bug 122443 - Check that INI files can be created from scratch.

         Revision 1.1.1.1  2000/11/10 03:04:01  rbowen
         Initial checkin of the Config::IniFiles source to SourceForge

         Revision 1.8  2000/10/17 01:52:55  rbowen
         Patch from Jeremy. Fixed "defined" warnings.

         Revision 1.7  2000/09/21 11:19:17  rbowen
         Mostly documentation changes. I moved the change log into the POD rather
         than having it in a separate Changes file. This allows people to see the
         changes in the Readme before they download the module. Now I just
         need to make sure I remember to regenerate the Readme every time I do
         a commit.

         1.6 September 19, 2000 by JW, AS
         * Applied several patches submitted to me by Jeremy and Alex.
         * Changed version number to the CVS version number, so that I won't
         have to think about changing it ever again. Big version change
         should not be taken as a huge leap forward.

         0.12 September 13, 2000 by JW/WADG
         * Added documentation to clarify autovivification issues when 
         creating new sections
         * Fixed version number (Oops!)

         0.11 September 13, 2000 by JW/WADG
         * Applied patch to Group and GroupMembers functions to return empty
         list when no groups are present (submitted by John Bass, Sep 13)

         0.10 September 13, 2000 by JW/WADG
         * Fixed reference in POD to ReWriteFile. changes to RewriteConfig
         * Applied patch for failed open bug submitted by Mordechai T. Abzug Aug 18
         * Doc'd behavior of failed open
         * Removed planned SIG testing from test.pl as SIGs have been removed
         * Applied patch from Thibault Deflers to fix bug in parameter list
         when a parameter value is undef

         0.09
         Hey! Where's the change log for 0.09?

         0.08
         2000-07-30  Adrian Phillips  <adrianp@powertech.no>
 
         * test.pl: Fixed some tests which use $\, and made those that try
         to check a non existant val check against ! defined.

         * IniFiles.pm: hopefully fixed use of $\ when this is unset
         (problems found when running tests with -w).  Similar problem with
         $/ which can be undefined and trying to return a val which does
         not exist. Modified val docs section to indicate a undef return
         when this occurs.

         0.07
         Looks like we missed a change log for 0.07. Bummer.

         0.06 Sun Jun 25, 2000 by Daniel Winkelmann
         * Patch for uninitialized value bug in newval and setval
     
         0.05 Sun Jun 18, 2000 by RBOW
         * Added something to shut up -w on VERSIONS
         * Removed unused variables

         0.04 Thu Jun 15 - Fri Jun 16, 2000 by JW/WADG
         * Added support for -import option on ->new
         * Added support for tying a hash
         * Edited POD for grammer, clarity and updates
         * Updated test.pl file
         * Fixed bug in multiline/single line output
         * Fixed bug in default handling with tie interface
         * Added bugs to test.pl for regression
         * Fixed bug in {group} vs. {groups} property (first is valid)
         * Fixed return value for empty {sects} or {parms}{$sect} in
         Sections and Parameters methods

         0.03 Thu Jun 15, 2000 by RBOW
         * Modifications to permit 'use strict', and to get 'make test' working
         again.

         0.02 Tue Jun 13, 2000 by RBOW
         * Fixed bug reported by Bernie Cosell - Sections, Parameters, 
         and GroupMembers return undef if there are no sections,
         parameters, or group members. These functions now return
         () if the particular value is undefined.
         * Added some contributed documentation, from Alex Satrapa, explaining
         how the internal data structure works. 
         * Set up a project on SourceForge. (Not a change, but worth
         noting).
         * Added Groups method to return a list of section groups.

         0.01  Mon Jun 12, 2000 by RBOW
         Some general code cleanup, in preparation for changes to
         come. Put up Majordomo mailing list and sent invitation to
         various people to join it.

