NAME

       Devel::Symdump - dump symbol names or the symbol table

SYNOPSIS

           # Constructor
           require Devel::Symdump;
           @packs = qw(some_package another_package);
           $obj = Devel::Symdump->new(@packs);        # no recursion
           $obj = Devel::Symdump->rnew(@packs);       # with recursion

           # Methods
           @array = $obj->packages;
           @array = $obj->scalars;
           @array = $obj->arrays;
           @array = $obj->hashes;
           @array = $obj->functions;
           @array = $obj->filehandles;  # deprecated, use ios instead
           @array = $obj->dirhandles;   # deprecated, use ios instead
           @array = $obj->ios;
           @array = $obj->unknowns;     # only perl version < 5.003 had some

           $string = $obj->as_string;
           $string = $obj->as_HTML;
           $string = $obj1->diff($obj2);

           $string = Devel::Symdump->isa_tree;    # or $obj->isa_tree
           $string = Devel::Symdump->inh_tree;    # or $obj->inh_tree

           # Methods with autogenerated objects
           # all of those call new(@packs) internally
           @array = Devel::Symdump->packages(@packs);
           @array = Devel::Symdump->scalars(@packs);
           @array = Devel::Symdump->arrays(@packs);
           @array = Devel::Symdump->hashes(@packs);
           @array = Devel::Symdump->functions(@packs);
           @array = Devel::Symdump->ios(@packs);
           @array = Devel::Symdump->unknowns(@packs);

DESCRIPTION

       This little package serves to access the symbol table of perl.

       "Devel::Symdump->rnew(@packages)"
           returns a symbol table object for all subtrees below @packages.  Nested Modules are
           analyzed recursively. If no package is given as argument, it defaults to "main". That
           means to get the whole symbol table, just do a "rnew" without arguments.

           The global variable $Devel::Symdump::MAX_RECURSION limits the recursion to prevent
           contention. The default value is set to 97, just low enough to survive the test suite
           without a warning about deep recursion.

       "Devel::Symdump->new(@packages)"
           does not go into recursion and only analyzes the packages that are given as arguments.

       packages, scalars, arrays, hashes, functions, ios
           The methods packages(), scalars(), arrays(), hashes(), functions(), ios(), and (for
           older perls) unknowns() each return an array of fully qualified symbols of the
           specified type in all packages that are held within a Devel::Symdump object, but
           without the leading "$", "@" or "%". In a scalar context, they will return the number
           of such symbols. Unknown symbols are usually either formats or variables that haven't
           yet got a defined value.

           Note that scalar symbol table entries are a special case.  If a symbol table entry
           exists at all, presence of a scalar is currently unknowable, due to a feature of Perl
           described in "Making References" in perlref point 7.  For example, this package will
           mark a scalar value $foo as present if any of @foo, %foo, &foo etc. have been declared
           or used.

       as_string
       as_HTML
           As_string() and as_HTML() return a simple string/HTML representations of the object.

       diff
           Diff() prints the difference between two Devel::Symdump objects in human readable
           form. The format is similar to the one used by the as_string method.

       isa_tree
       inh_tree
           Isa_tree() and inh_tree() both return a simple string representation of the current
           inheritance tree. The difference between the two methods is the direction from which
           the tree is viewed: top-down or bottom-up. As I'm sure, many users will have different
           expectation about what is top and what is bottom, I'll provide an example what happens
           when the Socket module is loaded:

       % print Devel::Symdump->inh_tree
               AutoLoader
                       DynaLoader
                               Socket
               DynaLoader
                       Socket
               Exporter
                       Carp
                       Config
                       Socket

           The inh_tree method shows on the left hand side a package name and indented to the
           right the packages that use the former.

       % print Devel::Symdump->isa_tree
               Carp
                       Exporter
               Config
                       Exporter
               DynaLoader
                       AutoLoader
               Socket
                       Exporter
                       DynaLoader
                               AutoLoader

           The isa_tree method displays from left to right ISA relationships, so Socket IS A
           DynaLoader and DynaLoader IS A AutoLoader. (Actually, they were at the time this
           manpage was written)

       You may call both methods, isa_tree() and inh_tree(), with an object. If you do that, the
       object will store the output and retrieve it when you call the same method again later.
       The typical usage would be to use them as class methods directly though.

SUBCLASSING

       The design of this package is intentionally primitive and allows it to be subclassed
       easily. An example of a (maybe) useful subclass is Devel::Symdump::Export, a package which
       exports all methods of the Devel::Symdump package and turns them into functions.

SEE ALSO

       Routines for manipulating stashes: "Package::Stash"; to work with lexicals: "PadWalker".

AUTHORS

       Andreas Koenig <andk@cpan.org> and Tom Christiansen <tchrist@perl.com>. Based on the old
       dumpvar.pl by Larry Wall.

COPYRIGHT, LICENSE

       This module is

       Copyright (c) 1995, 1997, 2000, 2002, 2005, 2006 Andreas Koenig "<andk@cpan.org>".

       All rights reserved.

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