Module introspection
You can inspect the namespace of an imported module, for example:
$ perl -MLWP::UserAgent -d -e 1
Loading DB routines from perl5db.pl version 1.32
Editor support available.
Enter h or `h h' for help, or `man perldebug' for more help.
main::(-e:1): 1
DB<1> x \%{'LWP::UserAgent::'}
0 HASH(0x9dee070)
'BEGIN' => *LWP::UserAgent::BEGIN
'ISA' => *LWP::UserAgent::ISA
'VERSION' => *LWP::UserAgent::VERSION
'__ANON__[/usr/share/perl5/LWP/UserAgent.pm:608]' => *LWP::UserAgent::__ANON__[/usr/share/perl5/LWP/UserAgent.pm:608]
'__ANON__[/usr/share/perl5/LWP/UserAgent.pm:611]' => *LWP::UserAgent::__ANON__[/usr/share/perl5/LWP/UserAgent.pm:611]
'__ANON__[/usr/share/perl5/LWP/UserAgent.pm:632]' => *LWP::UserAgent::__ANON__[/usr/share/perl5/LWP/UserAgent.pm:632]
'__ANON__[/usr/share/perl5/LWP/UserAgent.pm:635]' => *LWP::UserAgent::__ANON__[/usr/share/perl5/LWP/UserAgent.pm:635]
'__ANON__[/usr/share/perl5/LWP/UserAgent.pm:735]' => *LWP::UserAgent::__ANON__[/usr/share/perl5/LWP/UserAgent.pm:735]
'_agent' => *LWP::UserAgent::_agent
'_need_proxy' => *LWP::UserAgent::_need_proxy
'_new_response' => *LWP::UserAgent::_new_response
'_process_colonic_headers' => *LWP::UserAgent::_process_colonic_headers
'add_handler' => *LWP::UserAgent::add_handler
'agent' => *LWP::UserAgent::agent
'clone' => *LWP::UserAgent::clone
'conn_cache' => *LWP::UserAgent::conn_cache
'cookie_jar' => *LWP::UserAgent::cookie_jar
'credentials' => *LWP::UserAgent::credentials
'default_header' => *LWP::UserAgent::default_header
'default_headers' => *LWP::UserAgent::default_headers
'env_proxy' => *LWP::UserAgent::env_proxy
'from' => *LWP::UserAgent::from
'get' => *LWP::UserAgent::get
'get_basic_credentials' => *LWP::UserAgent::get_basic_credentials
'get_my_handler' => *LWP::UserAgent::get_my_handler
'handlers' => *LWP::UserAgent::handlers
'head' => *LWP::UserAgent::head
'import' => *LWP::UserAgent::import
'is_protocol_supported' => *LWP::UserAgent::is_protocol_supported
'local_address' => *LWP::UserAgent::local_address
'max_redirect' => *LWP::UserAgent::max_redirect
'max_size' => *LWP::UserAgent::max_size
'mirror' => *LWP::UserAgent::mirror
'new' => *LWP::UserAgent::new
'no_proxy' => *LWP::UserAgent::no_proxy
'parse_head' => *LWP::UserAgent::parse_head
'post' => *LWP::UserAgent::post
'prepare_request' => *LWP::UserAgent::prepare_request
'progress' => *LWP::UserAgent::progress
'protocols_allowed' => *LWP::UserAgent::protocols_allowed
'protocols_forbidden' => *LWP::UserAgent::protocols_forbidden
'proxy' => *LWP::UserAgent::proxy
'redirect_ok' => *LWP::UserAgent::redirect_ok
'remove_handler' => *LWP::UserAgent::remove_handler
'request' => *LWP::UserAgent::request
'requests_redirectable' => *LWP::UserAgent::requests_redirectable
'run_handlers' => *LWP::UserAgent::run_handlers
'send_request' => *LWP::UserAgent::send_request
'set_my_handler' => *LWP::UserAgent::set_my_handler
'show_progress' => *LWP::UserAgent::show_progress
'simple_request' => *LWP::UserAgent::simple_request
'timeout' => *LWP::UserAgent::timeout
'use_alarm' => *LWP::UserAgent::use_alarm
'use_eval' => *LWP::UserAgent::use_eval
DB<2>
Determining specific types of the values in the namespace
Functions:
DB<1> %ns = %{'LWP::UserAgent::'}
DB<4> p join ", ", grep { defined &{$ns{$_}} } keys %ns
run_handlers, set_my_handler, post, default_headers, prepare_request, credentials, clone, requests_redirectable, timeout, new, parse_head, request, send_request, head, _new_response, conn_cache, protocols_forbidden, show_progress, _need_proxy, no_proxy, protocols_allowed, local_address, use_eval, get_basic_credentials, remove_handler, proxy, max_size, add_handler, mirror, get_my_handler, simple_request, from, get, env_proxy, _agent, max_redirect, redirect_ok, progress, use_alarm, handlers, default_header, _process_colonic_headers, is_protocol_supported, agent, cookie_jar
Scalars:
DB<5> p join ", ", grep { defined ${$ns{$_}} } keys %ns
VERSION
Arays:
DB<7> p join ", ", grep { defined @{$ns{$_}} } keys %ns
ISA
Another example - not in the debugger
Source:
use strict;
use warnings;
package wibble;
use vars qw($apple @fish %moose);
our $cat_undefined;
our $cat_defined = "meow";
my $hiddenval = 42;
package main;
use Data::Dumper;
my %b_ns = do { no strict "refs"; %{"wibble::"} };
print Dumper(\%b_ns);
print "\n";
print "wibble::apple exists: " . do { exists $b_ns{apple} ? 'yes' : 'no' } . "\n";
print "wibble::hiddenval exists: " . do { exists $b_ns{hiddenval} ? 'yes' : 'no' } . "\n";
print "\n";
print '$wibble::apple defined: ' . do { defined $wibble::apple ? 'yes' : 'no' } . "\n";
print '@wibble::apple defined: ' . do { defined @wibble::apple ? 'yes' : 'no' } . "\n";
print '%wibble::apple defined: ' . do { defined %wibble::apple ? 'yes' : 'no' } . "\n";
print '*wibble::apple defined: ' . do { defined *wibble::apple ? 'yes' : 'no' } . "\n";
print "\n";
print '$wibble::cat_defined defined: ' . do { defined $wibble::cat_defined ? 'yes' : 'no' } . "\n";
print '@wibble::cat_defined defined: ' . do { defined @wibble::cat_defined ? 'yes' : 'no' } . "\n";
print '%wibble::cat_defined defined: ' . do { defined %wibble::cat_defined ? 'yes' : 'no' } . "\n";
print '*wibble::cat_defined defined: ' . do { defined *wibble::cat_defined ? 'yes' : 'no' } . "\n";
Output:
$VAR1 = {
'apple' => *wibble::apple,
'cat_undefined' => *wibble::cat_undefined,
'BEGIN' => *wibble::BEGIN,
'cat_defined' => *wibble::cat_defined,
'moose' => *wibble::moose,
'fish' => *wibble::fish
};
wibble::apple exists: yes
wibble::hiddenval exists: no
$wibble::apple defined: no
@wibble::apple defined: no
%wibble::apple defined: no
*wibble::apple defined: yes
$wibble::cat_defined defined: yes
@wibble::cat_defined defined: no
%wibble::cat_defined defined: no
*wibble::cat_defined defined: yes