bionic (3) Devel::Symdump.3pm.gz

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.