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.