Module::Info(3) User Contributed Perl Documentation Module::Info(3)NAMEModule::Info - Information about Perl modules
SYNOPSIS
use Module::Info;
my $mod = Module::Info->new_from_file('Some/Module.pm');
my $mod = Module::Info->new_from_module('Some::Module');
my $mod = Module::Info->new_from_loaded('Some::Module');
my @mods = Module::Info->all_installed('Some::Module');
my $name = $mod->name;
my $version = $mod->version;
my $dir = $mod->inc_dir;
my $file = $mod->file;
my $is_core = $mod->is_core;
# Only available in perl 5.6.1 and up.
# These do compile the module.
my @packages = $mod->packages_inside;
my @used = $mod->modules_used;
my @subs = $mod->subroutines;
my @isa = $mod->superclasses;
my @calls = $mod->subroutines_called;
# Check for constructs which make perl hard to predict.
my @methods = $mod->dynamic_method_calls;
my @lines = $mod->eval_string; *UNIMPLEMENTED*
my @lines = $mod->gotos; *UNIMPLEMENTED*
my @controls = $mod->exit_via_loop_control; *UNIMPLEMENTED*
my @unpredictables = $mod->has_unpredictables; *UNIMPLEMENTED*
# set/get Module::Info options
$self->die_on_compilation_error(1);
my $die_on_error = $mod->die_on_compilation_error;
$self->safe(1);
my $safe = $mod->safe;
DESCRIPTIONModule::Info gives you information about Perl modules without actually
loading the module. It actually isn't specific to modules and should
work on any perl code.
METHODS
Constructors
There are a few ways to specify which module you want information for.
They all return Module::Info objects.
new_from_file
my $module = Module::Info->new_from_file('path/to/Some/Module.pm');
Given a file, it will interpret this as the module you want
information about. You can also hand it a perl script.
If the file doesn't exist or isn't readable it will return false.
new_from_module
my $module = Module::Info->new_from_module('Some::Module');
my $module = Module::Info->new_from_module('Some::Module', @INC);
Given a module name, @INC will be searched and the first module
found used. This is the same module that would be loaded if you
just say "use Some::Module".
If you give your own @INC, that will be used to search instead.
new_from_loaded
my $module = Module::Info->new_from_loaded('Some::Module');
Gets information about the currently loaded version of
Some::Module. If it isn't loaded, returns false.
all_installed
my @modules = Module::Info->all_installed('Some::Module');
my @modules = Module::Info->all_installed('Some::Module', @INC);
Like new_from_module(), except all modules in @INC will be
returned, in the order they are found. Thus $modules[0] is the one
that would be loaded by "use Some::Module".
Information without loading
The following methods get their information without actually compiling
the module.
name
my $name = $module->name;
$module->name($name);
Name of the module (ie. Some::Module).
Module loaded using new_from_file() won't have this information in
which case you can set it yourself.
version
my $version = $module->version;
Divines the value of $VERSION. This uses the same method as
ExtUtils::MakeMaker and all caveats therein apply.
inc_dir
my $dir = $module->inc_dir;
Include directory in which this module was found. Module::Info
objects created with new_from_file() won't have this info.
file
my $file = $module->file;
The absolute path to this module.
is_core
my $is_core = $module->is_core;
Checks if this module is the one distributed with Perl.
NOTE This goes by what directory it's in. It's possible that the
module has been altered or upgraded from CPAN since the original
Perl installation.
Information that requires loading.
WARNING! From here down reliability drops rapidly!
The following methods get their information by compiling the module and
examining the opcode tree. The module will be compiled in a seperate
process so as not to disturb the current program.
They will only work on 5.6.1 and up and requires the B::Utils module.
packages_inside
my @packages = $module->packages_inside;
Looks for any explicit "package" declarations inside the module and
returns a list. Useful for finding hidden classes and
functionality (like Tie::StdHandle inside Tie::Handle).
KNOWN BUG Currently doesn't spot package changes inside
subroutines.
package_versions
my %versions = $module->package_versions;
Returns a hash whose keys are the packages contained in the module
(these are the same as what's returned by "packages_inside()"), and
whose values are the versions of those packages.
modules_used
my @used = $module->modules_used;
Returns a list of all modules and files which may be "use"'d or
"require"'d by this module.
NOTE These modules may be conditionally loaded, can't tell. Also
can't find modules which might be used inside an "eval".
modules_required
my %required = $module->modules_required;
Returns a list of all modules and files which may be "use"'d or
"require"'d by this module, together with the minimum required
version.
The hash is keyed on the module/file name, the corrisponding value
is an array reference containing the requied versions, or an empty
array if no specific version was required.
NOTE These modules may be conditionally loaded, can't tell. Also
can't find modules which might be used inside an "eval".
subroutines
my %subs = $module->subroutines;
Returns a hash of all subroutines defined inside this module and
some info about it. The key is the *full* name of the subroutine
(ie. $subs{'Some::Module::foo'} rather than just $subs{'foo'}),
value is a hash ref with information about the subroutine like so:
start => line number of the first statement in the subroutine
end => line number of the last statement in the subroutine
Note that the line numbers may not be entirely accurate and will
change as perl's backend compiler improves. They typically
correspond to the first and last run-time statements in a
subroutine. For example:
sub foo {
package Wibble;
$foo = "bar";
return $foo;
}
Taking "sub foo {" as line 1, Module::Info will report line 3 as
the start and line 4 as the end. "package Wibble;" is a compile-
time statement. Again, this will change as perl changes.
Note this only catches simple "sub foo {...}" subroutine
declarations. Anonymous, autoloaded or eval'd subroutines are not
listed.
superclasses
my @isa = $module->superclasses;
Returns the value of @ISA for this $module. Requires that
$module->name be set to work.
NOTE superclasses() is currently cheating. See CAVEATS below.
subroutines_called
my @calls = $module->subroutines_called;
Finds all the methods and functions which are called inside the
$module.
Returns a list of hashes. Each hash represents a single function
or method call and has the keys:
line line number where this call originated
class class called on if its a class method
type function, symbolic function, object method,
class method, dynamic object method or
dynamic class method.
(NOTE This format will probably change)
name name of the function/method called if not dynamic
Information about Unpredictable Constructs
Unpredictable constructs are things that make a Perl program hard to
predict what its going to do without actually running it. There's
nothing wrong with these constructs, but its nice to know where they
are when maintaining a piece of code.
dynamic_method_calls
my @methods = $module->dynamic_method_calls;
Returns a list of dynamic method calls (ie. "$obj-"$method()>) used
by the $module. @methods has the same format as the return value
of subroutines_called().
Options
The following methods get/set specific option values for the
Module::Info object.
die_on_compilation_error
$module->die_on_compilation_error(0); # default
$module->die_on_compilation_error(1);
my $flag = $module->die_on_compilation_error;
Sets/gets the "die on compilation error" flag. When the flag is off
(default), and a module fails to compile, Module::Info simply emits
a watning and continues. When the flag is on and a module fails to
compile, Module::Info "die()"s with the same error message it would
use in the warning.
safe
$module->safe(0); # default
$module->safe(1); # be safer
my $flag = $module->safe;
Sets/gets the "safe" flag. When the flag is enabled all operations
requiring module compilation are forbidden and the "version()"
method executes its code in a "Safe" compartment.
use_version
$module->use_version(0); # do not use version.pm (default)
$module->use_version(1); # use version.pm, die if not present
my $flag = $module->use_version;
Sets/gets the "use_version" flag. When the flag is enabled the
'version' method always returns a version object.
AUTHOR
Michael G Schwern <schwern@pobox.com> with code from ExtUtils::MM_Unix,
Module::InstalledVersion and lots of cargo-culting from B::Deparse.
Mattia Barbon <mbarbon@cpan.org> is the current maintainer.
LICENSE
This program is free software; you can redistribute it and/or modify it
under the same terms as Perl itself.
THANKS
Many thanks to Simon Cozens and Robin Houston for letting me chew their
ears about B.
CAVEATS
Code refs in @INC are currently ignored. If this bothers you submit a
patch.
superclasses() is cheating and just loading the module in a seperate
process and looking at @ISA. I don't think its worth the trouble to go
through and parse the opcode tree as it still requires loading the
module and running all the BEGIN blocks. Patches welcome.
I originally was going to call superclasses()isa() but then I
remembered that would be bad.
All the methods that require loading are really inefficient as they're
not caching anything. I'll worry about efficiency later.
perl v5.14.1 2011-06-20 Module::Info(3)
