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 a command-line interface 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:

            my $s = {

            a => [ 10, 20, "thirty" ],
            b => {
                    "w" => "forty",
                    "x" => "fifty",
                    "y" => 60,
                    "z" => \70,
            },
            c => sub { print "I'm a data structure!\n"; },
            d => 80,
            };
            $s->{e} = \$s->{d};

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

            /> 
            /> ls -l
            a               ARRAY                     (3)
            b               HASH                      (4)
            c               CODE                      
            d               scalar                    80
            e               SCALAR                    80
            /> cd a
            /->{a}> ls -al
            ..              HASH                      (5)
            .               ARRAY                     (3)
            0               scalar                    10
            1               scalar                    20
            2               scalar                    'thirty'
            /->{a}> cd ../b
            /->{b}> ls -al
            ..              HASH                      (5)
            .               HASH                      (4)
            w               scalar                    'forty'
            x               scalar                    'fifty'
            y               scalar                    60
            z               SCALAR                    70
            /->{b}> cd ..
            /> dump b
            dump--> 'b'
            $b = {
              'x' => 'fifty',
              'y' => 60,
              'z' => \70,
              'w' => 'forty'
            };
            /> ls -al
            ..              HASH                      (5)
            .               HASH                      (5)
            a               ARRAY                     (3)
            b               HASH                      (4)
            c               CODE                      
            d               scalar                    80
            e               SCALAR                    80
            /> ! $ref->{d} += 3
            eval--> $ref->{d} += 3
            
            83
            /> ls -al
            ..              HASH                      (5)
            .               HASH                      (5)
            a               ARRAY                     (3)
            b               HASH                      (4)
            c               CODE                      
            d               scalar                    83
            e               SCALAR                    83
            /> 
            
            
    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
            ! or eval            eval arbitrary perl (careful!)
            help                 this help message
            help set             lists the available 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
            scalarname      (default: 'scalar') how simple scalars are listed
            undefname       (default: 'undef' ) how simple scalars are listed

            maxdepth        (default:   1  )  maximum dump-depth (Data::Dumper)
            indent          (default:   1  )  amount of indent (Data::Dumper)
            lscol1width     (default:  15  )  column widths for 'ls' displays
            lscol2width     (default:  25  )  column widths for 'ls' displays

            showrecursion   (default:   1  )  note recursion in the prompt
            showids         (default:   0  )  show ref id numbers in ls lists
            skipdoublerefs  (default:   1  )  hop over ref-to-refs during walks
            skipwarning     (default:   1  )  warn when hopping over ref-to-refs
            truncatescalars (default:  37  )  truncate scalars in 'ls' displays

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

    This is an alpha release of this module. Future releases will
    include better documentation and tests.

CHANGES
    Version 0.13

            Added some installation tests.
            Numerous internal changes; one or two bug fixes.

    Version 0.12

            Blessed references to non-hashes are now handled correctly.
            Modified the output of "ls" commands (looks different).
            Added new options:  
               showids, lscol2width, scalarname, undefname,
               skipwarning
            Numerous internal changes.

    Version 0.11

            Fixed some misspellings in the help information.
            Modified the pretty-print format of scalars.
            Added some new comments to the source code.
            Various other small updates.

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