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Module::ScanDeps(3)                  User Contributed Perl Documentation                 Module::ScanDeps(3)



NAME
       Module::ScanDeps - Recursively scan Perl code for dependencies

SYNOPSIS
       Via the command-line program scandeps.pl:

           % scandeps.pl *.pm          # Print PREREQ_PM section for *.pm
           % scandeps.pl -e "use utf8" # Read script from command line
           % scandeps.pl -B *.pm       # Include core modules
           % scandeps.pl -V *.pm       # Show autoload/shared/data files

       Used in a program;

           use Module::ScanDeps;

           # standard usage
           my $hash_ref = scan_deps(
               files   => [ 'a.pl', 'b.pl' ],
               recurse => 1,
           );

           # shorthand; assume recurse == 1
           my $hash_ref = scan_deps( 'a.pl', 'b.pl' );

           # App::Packer::Frontend compatible interface
           # see App::Packer::Frontend for the structure returned by get_files
           my $scan = Module::ScanDeps->new;
           $scan->set_file( 'a.pl' );
           $scan->set_options( add_modules => [ 'Test::More' ] );
           $scan->calculate_info;
           my $files = $scan->get_files;

DESCRIPTION
       This module scans potential modules used by perl programs, and returns a hash reference; its keys are
       the module names as appears in %INC (e.g. "Test/More.pm"); the values are hash references with this
       structure:

           {
               file    => '/usr/local/lib/perl5/5.8.0/Test/More.pm',
               key     => 'Test/More.pm',
               type    => 'module',    # or 'autoload', 'data', 'shared'
               used_by => [ 'Test/Simple.pm', ... ],
               uses    => [ 'Test/Other.pm', ... ],
           }

       One function, "scan_deps", is exported by default.  Other functions such as ("scan_line",
       "scan_chunk", "add_deps", "path_to_inc_name") are exported upon request.

       Users of App::Packer may also use this module as the dependency-checking frontend, by tweaking their
       p2e.pl like below:

           use Module::ScanDeps;
           ...
           my $packer = App::Packer->new( frontend => 'Module::ScanDeps' );
           ...

       Please see App::Packer::Frontend for detailed explanation on the structure returned by "get_files".

   scan_deps
           $rv_ref = scan_deps(
               files      => \@files,     recurse => $recurse,
               rv         => \%rv,        skip    => \%skip,
               compile    => $compile,    execute => $execute,
           );
           $rv_ref = scan_deps(@files); # shorthand, with recurse => 1

       This function scans each file in @files, registering their dependencies into %rv, and returns a
       reference to the updated %rv.  The meaning of keys and values are explained above.

       If $recurse is true, "scan_deps" will call itself recursively, to perform a breadth-first search on
       text files (as defined by the -T operator) found in %rv.

       If the "\%skip" is specified, files that exists as its keys are skipped.  This is used internally to
       avoid infinite recursion.

       If $compile or $execute is true, runs "files" in either compile-only or normal mode, then inspects
       their %INC after termination to determine additional runtime dependencies.

       If $execute is an array reference, runs the files contained in it instead of @files.

       If performance of the scanning process is a concern, "cache_file" can be set to a filename. The
       scanning results will be cached and written to the file. This will speed up the scanning process on
       subsequent runs.

       Additionally, an option "warn_missing" is recognized. If set to true, "scan_deps" issues a warning to
       STDERR for every module file that the scanned code depends but that wasn't found. Please note that
       this may also report numerous false positives. That is why by default, the heuristic silently drops
       all dependencies it cannot find.

   scan_deps_runtime
       Like scan_deps, but skips the static scanning part.

   scan_line
           @modules = scan_line($line);

       Splits a line into chunks (currently with the semicolon characters), and return the union of
       "scan_chunk" calls of them.

       If the line is "__END__" or "__DATA__", a single "__END__" element is returned to signify the end of
       the program.

       Similarly, it returns a single "__POD__" if the line matches "/^=\w/"; the caller is responsible for
       skipping appropriate number of lines until "=cut", before calling "scan_line" again.

   scan_chunk
           $module = scan_chunk($chunk);
           @modules = scan_chunk($chunk);

       Apply various heuristics to $chunk to find and return the module name(s) it contains.  In scalar
       context, returns only the first module or "undef".

   add_deps
           $rv_ref = add_deps( rv => \%rv, modules => \@modules );
           $rv_ref = add_deps( @modules ); # shorthand, without rv

       Resolves a list of module names to its actual on-disk location, by finding in @INC and
       @Module::ScanDeps::IncludeLibs; modules that cannot be found are skipped.

       This function populates the %rv hash with module/filename pairs, and returns a reference to it.

   path_to_inc_name
           $perl_name = path_to_inc_name($path, $warn)

       Assumes $path refers to a perl file and does it's best to return the name as it would appear in %INC.
       Returns undef if no match was found and a prints a warning to STDERR if $warn is true.

       E.g. if $path = perl/site/lib/Module/ScanDeps.pm then $perl_name will be Module/ScanDeps.pm.

NOTES
   @Module::ScanDeps::IncludeLibs
       You can set this global variable to specify additional directories in which to search modules without
       modifying @INC itself.

   $Module::ScanDeps::ScanFileRE
       You can set this global variable to specify a regular expression to identify what files to scan. By
       default it includes all files of the following types: .pm, .pl, .t and .al. Additionally, all files
       without a suffix are considered.

       For instance, if you want to scan all files then use the following:

       "$Module::ScanDeps::ScanFileRE = qr/./"

CAVEATS
       This module intentially ignores the BSDPAN hack on FreeBSD -- the additional directory is removed
       from @INC altogether.

       The static-scanning heuristic is not likely to be 100% accurate, especially on modules that
       dynamically load other modules.

       Chunks that span multiple lines are not handled correctly.  For example, this one works:

           use base 'Foo::Bar';

       But this one does not:

           use base
               'Foo::Bar';

SEE ALSO
       scandeps.pl is a bundled utility that writes "PREREQ_PM" section for a number of files.

       An application of Module::ScanDeps is to generate executables from scripts that contains prerequisite
       modules; this module supports two such projects, PAR and App::Packer.  Please see their respective
       documentations on CPAN for further information.

AUTHORS
       Audrey Tang <cpan@audreyt.org>

       To a lesser degree: Steffen Mueller <smueller@cpan.org>

       Parts of heuristics were deduced from:

       •   PerlApp by ActiveState Tools Corp <http://www.activestate.com/>

       •   Perl2Exe by IndigoStar, Inc <http://www.indigostar.com/>

       The scan_deps_runtime function is contributed by Edward S. Peschko.

       <http://par.perl.org/> is the official website for this module.  You can write to the mailing list at
       <par@perl.org>, or send an empty mail to <par-subscribe@perl.org> to participate in the discussion.

       Please submit bug reports to <bug-Module-ScanDeps@rt.cpan.org>.

COPYRIGHT
       Copyright 2002-2008 by Audrey Tang <cpan@audreyt.org>; 2005-2010 by Steffen Mueller
       <smueller@cpan.org>.

       This program is free software; you can redistribute it and/or modify it under the same terms as Perl
       itself.

       See <http://www.perl.com/perl/misc/Artistic.html>



perl v5.12.5                                     2011-11-02                              Module::ScanDeps(3)