NAME
    Data::Walker - A tool for navigating through Perl data structures

SYNOPSIS
      use Data::Walker;
      Data::Walker->walk( $data_structure );
      # see below for details

DESCRIPTION
    This module allows you to "walk" an arbitrary Perl data structure in the
    same way that you can walk a directory tree from the command line. It is
    meant to be used interactively with a live user.

INSTALLATION
    To install this package, just change to the directory which you created
    by untarring the package, and type the following:

            perl Makefile.PL
            make test
            make
            make install

    This will copy Walker.pm to your perl library directory for use by all
    perl scripts. You probably must be root to do this, unless you have
    installed a personal copy of perl or you have write access to a Perl lib
    directory.

USAGE
    You open an interacive "command-prompt"-style session by invoking the
    walk function.

            use Data::Walker;
            Data::Walker->walk( $data_structure );

    You can customize certain features of the session, like so:

            use Data::Walker;
            $Data::Walker::Config{'skipdoublerefs'} = 0;
            Data::Walker->walk( $data_structure );

    If you prefer to use object-style notation, then you can use this syntax
    to customize the settings:

            use Data::Walker;
            my $w1 = new Data::Walker;
            $w1->walk( $data_structure );

            my $w2 = new Data::Walker( 'skipdoublerefs' => 0 );
            $w2->walk( $data_structure );
            
            $w2->showrecursion(0);
            $w2->walk( $data_structure );

    Imagine a data structure like so:

            $s = {
                    a => [ 10, 20, 30 ],
                    b => { 
                            "x" => 40, 
                            "y" => 50, 
                            "z" => 60 
                    },
            };
            $s->{c} = \$s->{a};       

    Here is a sample interactive session examining this structure ('/>' is
    the prompt):

            /> ls -al
            ..                    HASH (3)
            .                     HASH (3)
            a                     ARRAY (3)
            b                     HASH (3)
            c                     REF->ARRAY (3)     
            /> cd a
            /->{a}> ls -l
            0                     scalar: 10
            1                     scalar: 20
            2                     scalar: 30
            /->{a}>          
            /->{a}> cd ..
            /> dump b
            dump--> 'b'
            $b = {
              'x' => 40,
              'y' => 50,
              'z' => 60
            };
            />              

    The following commands are available from within the command-line
    session. With these commands, you can navigate around the data structure
    as if it were a directory tree.

            cd <target>          like UNIX cd
            ls                   like UNIX ls (also respects options -a, -l)
            print <target>       prints the item as a scalar
            dump <target>        invokes Data::Dumper
            set <key> <value>    set configuration variables
            show <key>           show configuration variables
            help                 this help message
            help set             lists the availabe config variables

    For each session, the following items can be configured:

            rootname        (default:  '/' )  How the root node is displayed 
            refname         (default: 'ref')  how embedded refs are listed
            maxdepth        (default:   1  )  maximum dump-depth (Data::Dumper)
            indent          (default:   1  )  amount of indent (Data::Dumper)
            lscolwidth      (default:  30  )  column withs for 'ls' displays

            showrecursion   (default:   1  )  note recursion in the prompt
            skipdoublerefs  (default:   1  )  hop over ref-to-refs during walks
            truncatescalars (default:   0  )  truncate scalars in 'ls' displays

            promptchar      (default:  '>' )  customize the session prompt
            arrowhead       (default:  '>' )  ('>' in '->')
            arrowshaft      (default:  '-' )  ('-' in '->')

    This is the initial release of this module. Future releases will include
    better documentation and tests.

AUTHOR
    John Nolan jpnolan@op.net August 1999. A copyright statment is contained
    within the source code itself.