1Devel::Symdump(3) User Contributed Perl Documentation Devel::Symdump(3)
2
6 Devel::Symdump - dump symbol names or the symbol table
7
9 # Constructor
10 require Devel::Symdump;
11 @packs = qw(some_package another_package);
12 $obj = Devel::Symdump->new(@packs); # no recursion
13 $obj = Devel::Symdump->rnew(@packs); # with recursion
14 # Methods
16 @array = $obj->packages;
17 @array = $obj->scalars;
18 @array = $obj->arrays;
19 @array = $obj->hashes;
20 @array = $obj->functions;
21 @array = $obj->filehandles; # deprecated, use ios instead
22 @array = $obj->dirhandles; # deprecated, use ios instead
23 @array = $obj->ios;
24 @array = $obj->unknowns; # only perl version < 5.003 had some
25 $string = $obj->as_string;
27 $string = $obj->as_HTML;
28 $string = $obj1->diff($obj2);
29 $string = Devel::Symdump->isa_tree; # or $obj->isa_tree
31 $string = Devel::Symdump->inh_tree; # or $obj->inh_tree
32 # Methods with autogenerated objects
34 # all of those call new(@packs) internally
35 @array = Devel::Symdump->packages(@packs);
36 @array = Devel::Symdump->scalars(@packs);
37 @array = Devel::Symdump->arrays(@packs);
38 @array = Devel::Symdump->hashes(@packs);
39 @array = Devel::Symdump->functions(@packs);
40 @array = Devel::Symdump->ios(@packs);
41 @array = Devel::Symdump->unknowns(@packs);
42
44 This little package serves to access the symbol table of perl.
45 "Devel::Symdump->rnew(@packages)"
47 returns a symbol table object for all subtrees below @packages.
48 Nested Modules are analyzed recursively. If no package is given as
49 argument, it defaults to "main". That means to get the whole symbol
50 table, just do a "rnew" without arguments.
51 The global variable $Devel::Symdump::MAX_RECURSION limits the
53 recursion to prevent contention. The default value is set to 97,
54 just low enough to survive the test suite without a warning about
55 deep recursion.
56 "Devel::Symdump->new(@packages)"
58 does not go into recursion and only analyzes the packages that are
59 given as arguments.
60 packages, scalars, arrays, hashes, functions, ios
62 The methods packages(), scalars(), arrays(), hashes(), functions(),
63 ios(), and (for older perls) unknowns() each return an array of
64 fully qualified symbols of the specified type in all packages that
65 are held within a Devel::Symdump object, but without the leading
66 "$", "@" or "%". In a scalar context, they will return the number
67 of such symbols. Unknown symbols are usually either formats or
68 variables that haven't yet got a defined value.
69 Note that scalar symbol table entries are a special case. If a
71 symbol table entry exists at all, presence of a scalar is currently
72 unknowable, due to a feature of Perl described in "Making
73 References" in perlref point 7. For example, this package will
74 mark a scalar value $foo as present if any of @foo, %foo, &foo etc.
75 have been declared or used.
76 as_string
78 as_HTML
79 As_string() and as_HTML() return a simple string/HTML
80 representations of the object.
81 diff
83 Diff() prints the difference between two Devel::Symdump objects in
84 human readable form. The format is similar to the one used by the
85 as_string method.
86 isa_tree
88 inh_tree
89 Isa_tree() and inh_tree() both return a simple string
90 representation of the current inheritance tree. The difference
91 between the two methods is the direction from which the tree is
92 viewed: top-down or bottom-up. As I'm sure, many users will have
93 different expectation about what is top and what is bottom, I'll
94 provide an example what happens when the Socket module is loaded:
95 % print Devel::Symdump->inh_tree
97 AutoLoader
98 DynaLoader
99 Socket
100 DynaLoader
101 Socket
102 Exporter
103 Carp
104 Config
105 Socket
106 The inh_tree method shows on the left hand side a package name and
108 indented to the right the packages that use the former.
109 % print Devel::Symdump->isa_tree
111 Carp
112 Exporter
113 Config
114 Exporter
115 DynaLoader
116 AutoLoader
117 Socket
118 Exporter
119 DynaLoader
120 AutoLoader
121 The isa_tree method displays from left to right ISA relationships,
123 so Socket IS A DynaLoader and DynaLoader IS A AutoLoader.
124 (Actually, they were at the time this manpage was written)
125 You may call both methods, isa_tree() and inh_tree(), with an object.
127 If you do that, the object will store the output and retrieve it when
128 you call the same method again later. The typical usage would be to use
129 them as class methods directly though.
130
132 The design of this package is intentionally primitive and allows it to
133 be subclassed easily. An example of a (maybe) useful subclass is
134 Devel::Symdump::Export, a package which exports all methods of the
135 Devel::Symdump package and turns them into functions.
136
138 Routines for manipulating stashes: "Package::Stash"; to work with
139 lexicals: "PadWalker".
140
142 Andreas Koenig <andk@cpan.org> and Tom Christiansen <tchrist@perl.com>.
143 Based on the old dumpvar.pl by Larry Wall.
144
146 This module is
147 Copyright (c) 1995, 1997, 2000, 2002, 2005, 2006 Andreas Koenig
149 "<andk@cpan.org>".
150 All rights reserved.
152 This library is free software; you may use, redistribute and/or modify
154 it under the same terms as Perl itself.
155perl v5.34.0 2022-01-21 Devel::Symdump(3)