Devel::Symdump(3pm) User Contributed Perl Documentation Devel::Symdump(3pm)
Devel::Symdump - dump symbol names or the symbol table
@packs = qw(some_package another_package);
$obj = Devel::Symdump->new(@packs); # no recursion
$obj = Devel::Symdump->rnew(@packs); # with recursion
@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);
This little package serves to access the symbol table of perl.
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 $Devel::Symdump::MAX_RECURSION limits the
recursion to prevent contention. The default value is set to 97,
just low enough to survive the test suite without a warning about
does not go into recursion and only analyzes the packages that are
given as arguments.
packages, scalars, arrays, hashes, functions, ios
The methods packages(), scalars(), arrays(), hashes(), functions(),
ios(), and (for older perls) unknowns() each return an array of
fully qualified symbols of the specified type in all packages that
are held within a Devel::Symdump object, but without the leading
"$", "@" 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.
As_string() and as_HTML() return a simple string/HTML representa-
tions of the object.
Diff() prints the difference between two Devel::Symdump objects in
human readable form. The format is similar to the one used by the
Isa_tree() and inh_tree() both return a simple string representa-
tion 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
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
The isa_tree method displays from left to right ISA relationships,
so Socket IS A DynaLoader and DynaLoader IS A AutoLoader. (Actu-
ally, 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.
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.
Andreas Koenig <firstname.lastname@example.org> and Tom Christiansen <email@example.com>.
Based on the old dumpvar.pl by Larry Wall.
This module is
Copyright (c) 1995, 1997, 2000, 2002, 2005, 2006 Andreas Koenig
All rights reserved.
This library is free software; you may use, redistribute and/or modify
it under the same terms as Perl itself.
perl v5.8.8 2008-04-01 Devel::Symdump(3pm)