Module::ScanDeps::Static - a cleanup of rpmbuild's perl.req


 my $scanner = Module::ScanDeps::Static->new({ file => '' });
 print $scanner->format_text;


This module is a mashup (and cleanup) of the `/usr/lib/rpm/perl.req` file found in the rpm build tools library (see "LICENSE") below.

Successful identification of the required Perl modules for a module or script is the subject of more than one project on CPAN. While each approach has its pros and cons I have yet to find a better scanner than the simple parser that Ken Estes wrote for the rpm build tools package.

Module::ScanDeps::Static is a simple static scanner that essentially uses regular expressions to locate use, require, parent, and base in all of their disguised forms inside your Perl script or module. It's not perfect and the regular expressions could use some polishing, but it works on a broad enough set of situations as to be useful.

NOTE: Only direct dependencies are returned by this module. If you want a recursive search for dependencies, use


The methods and output of this module are subject to revision!

USAGE [options] Module

If "Module" is not provided, the script will read from STDIN.

Examples --no-core $(which --json $(which


--add-version, -a, --no-add-version

Add the version number to the dependency list by inspecting the version of the module in your @INC path.

default: --add-version

--core, -c, --no-core

Include or exclude core modules. See --min-core-version for description of how core modules are identified.

default: --core

--help, -h

Show usage.

--include-require, -i, --no-include-require

Include statements that have Require in them but are not necessarily on the left edge of the code (possibly in tests).

default: <--include-require>

--json, -j

Output the dependency list as a JSON encode string.

--min-core-version, -m

The minimum version of Perl that is considered core. Use this to consider some modules non-core if they did not appear until after the min-core-version.

Core modules are identified using Module::CoreList and comparing the first release value of the module with the the minimum version of Perl considered as a baseline. If you're using this module to identify the dependencies for your script AND you know you will be using a specific version of Perl, then set the min-core-version to that version of Perl.

default: 5.8.9

--separator, -s

Use the specified sting to separate modules and version numbers in formatted output.

default: ' => '

--text, -t

Output the dependency list as a simple text listing of module name and version in the same manner as

default: --text

--raw, -r

Output the list with no quotes separated by a single whitespace character.


For the purposes of this module, dependencies are identified by looking for Perl modules and other Perl artifacts declared using use, require, parent, or base.

If the module contains a require statement, by default the require must be flush up against the left edge of your script without any whitespace between it and beginning of the line. This is the default behavior to avoid identifying require statements that are embedded in if statements. If you want to include all of the targets of require statements as dependencies, set the include-require option to a true value.


  • Allow detection of require not at beginning of line.

    Use the --include-require to expand the definition of a dependency to any module or Perl script that is the argument of the require statement.

  • Allow detection of the parent, base statemens use of curly braces.

    The regular expression and algorithm in parse has been enhanced to detect the use of curly braces in use or parent declarations.

  • Exclude core modules.

    Use the --no-core option to ignore core modules.

  • Add the current version of installed module if version not explicitly specified.


There are still many situations (including multi-line statements) that may prevent this module from properly identifying a dependency. As always, YMMV.




Returns a Module::ScanDeps::Static object.



Boolean value that determines whether to consider require statements that are not left-aligned to be considered dependencies.

default: false


Boolean value that determines whether to include the version of the module currently installed if there is no version specified.

default: false


Boolean value that determines whether to include core modules as part of the dependency listing.

default: true


Boolean value that indicates output should be in JSON format.

default: false


The minimum version of Perl which will be used to decide if a module is include in Perl core.

default: 5.8.9


Character string to use formatting dependency list as text. This string will be used to separate the module name from the version.

default: ' => '

 Module::ScanDeps::Static 0.1

Boolean value that indicates output should be in the same format as

dafault: true


Boolean value that indicates output should be in raw format (module version).

default: false


After calling the parse() method, call this method to retrieve a hash containing the dependencies and (potentially) their version numbers.



parse a file
 my @dependencies = Module::ScanDeps::Static->new({ path => $path })->parse;
parse from file handle
 my @dependencies = Module::ScanDeps::Static->new({ handle => $path })->parse;
parse STDIN
 my @dependencies = Module::ScanDeps::Static->new->parse(\$script);
parse string
 my @dependencies = parse(\$script);

Scans the specified input and returns a list Perl modulde dependencies.

Use the get_dependencies method to retrieve the dependencies as a formatted string or as a list of dependency objects. Use the get_require and get_perlreq methods to retrieve dependencies as a list of hash refs.

 my $scanner = Module::ScanDeps::Static->new({ path => '' });
 my @dependencies = $scanner->parse;


Returns a formatted list of dependencies or a list of dependency objects.


 print $scanner->get_dependencies( format => 'json' )

    "name" : "Module::Name",
    "version" "version"

..or as text:

 print $scanner->get_dependencies( format => 'text' )

 Module::Name >= version

In scalar context in the absence of an argument returns a JSON formatted string. In list context will return a list of hashes that contain the keys "name" and "version" for each dependency.




This module is largely a lift and drop of Ken Este's `perl.req` script lifted from rpm build tools.

Ken Estes

The method `parse` is a cleaned up version of `process_file` from the same script.

Rob Lauer - <>


This statement was lifted right from perl.req...

    The entire code base may be distributed under the terms of the GNU General Public License (GPL), which appears immediately below. Alternatively, all of the source code in the lib subdirectory of the RPM source code distribution as well as any code derived from that code may instead be distributed under the GNU Library General Public License (LGPL), at the choice of the distributor. The complete text of the LGPL appears at the bottom of this file.

    This alternatively is allowed to enable applications to be linked against the RPM library (commonly called librpm) without forcing such applications to be distributed under the GPL.

    Any questions regarding the licensing of RPM should be addressed to Erik Troan <>