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File::Where



NAME

File::Where - find the absolute file for a program module; absolute dir for a repository


SYNOPSIS

 #######
 # Subroutine interface
 #  
 use File::Where qw(pm2require where where_dir where_file where_pm where_repository);
 $program_module                  = is_module(@program_modules);
 @program_modules                 = dir_pms( $dir );
 @program_modules                 = program_modules( $dir, 'file_flag', @dirs);
 $file                            = pm2require($pm);
 @program_modules                 = repository_pms($repository);
 $abs_file                        = where($relative_file);
 $abs_file                        = where($relative_file, \@path);
 ($abs_file, $inc_path, $rel_fle) = where($relative_file)
 ($abs_file, $inc_path, $rel_fle) = where($relative_file, \@path);
 $abs_dir                         = where($relative_dir, '', 'nofile'); 
 $abs_dir                         = where($relative_dir, \@path, 'nofile');
 ($abs_dir, $inc_path, $rel_dir)  = where($relative_dir, '', 'nofile');
 ($abs_dir, $inc_path, $rel_dir)  = where($relative_dir, \@path, 'nofile');
 $abs_dir                         = where_dir($relative_dir); 
 $abs_dir                         = where_dir($relative_dir, \@path; 
 $abs_dir                         = where_dir($relative_dir, @path;
 ($abs_dir, $inc_path, $rel_dir)  = where_dir($relative_dir);
 ($abs_dir, $inc_path, $rel_dir)  = where_dir($relative_dir, \@path);
 ($abs_dir, $inc_path, $rel_dir)  = where_dir($relative_dir, @path);
 $abs_file                        = where_file($relative_file);
 $abs_file                        = where_file($relative_file, \@path);
 $abs_file                        = where_file($relative_file, @path);
 ($abs_file, $inc_path, $rel_fle) = where_file($relative_file)
 ($abs_file, $inc_path, $rel_fle) = where_file($relative_file, \@path)
 ($abs_file, $inc_path, $rel_fle) = where_file($relative_file, @path)
 $abs_file                        = where_pm($pm); 
 $abs_file                        = where_pm($pm, \@path);
 $abs_file                        = where_pm($pm, @path);
 ($abs_file, $inc_path, $require) = where_pm($pm);
 ($abs_file, $inc_path, $require) = where_pm($pm, \@path);
 ($abs_file, $inc_path, $require) = where_pm($pm, @path);
 $abs_dir                         = where_repository($repository);
 $abs_dir                         = where_repository($repository, \@path);
 $abs_dir                         = where_repository($repository, @path);
 ($abs_dir,  $inc_path, $rel_dir) = where_repository($repository);
 ($abs_dir,  $inc_path, $rel_dir) = where_repository($repository, \@path);
 ($abs_dir,  $inc_path, $rel_dir) = where_repository($repository, @path);
 #######
 # Class interface
 #
 $program_module                  = File::Where->is_module(@program_modules);
 @program_modules                 = File::Where->dir_pms( $dir );
 @program_modules                 = File::Where->program_modules( $dir, 'file_flag', @dirs);
 $file                            = File::Where->pm2require($pm);
 @program_modules                 = File::Where->repository_pms($repository);

 $abs_file                        = File::Where->where($relative_file);
 $abs_file                        = File::Where->where($relative_file, \@path);
 $abs_dir                         = File::Where->where($relative_dir, '', 'nofile'); 
 $abs_dir                         = File::Where->where($relative_dir, \@path, 'nofile');
 ($abs_file, $inc_path, $require) = File::Where->where($relative_file)
 ($abs_file, $inc_path, $require) = File::Where->where($relative_file, \@path)
 ($abs_dir, $inc_path, $rel_dir)  = File::Where->where($relative_dir, '', 'nofile');
 ($abs_dir, $inc_path, $rel_dir)  = File::Where->where($relative_dir, \@path, 'nofile');
 $abs_dir                         = File::Where->where_dir($relative_dir); 
 $abs_dir                         = File::Where->where_dir($relative_dir, \@path; 
 $abs_dir                         = File::Where->where_dir($relative_dir, @path;
 ($abs_dir, $inc_path, $rel_dir)  = File::Where->where_dir($relative_dir);
 ($abs_dir, $inc_path, $rel_dir)  = File::Where->where_dir($relative_dir, \@path);
 ($abs_dir, $inc_path, $rel_dir)  = File::Where->where_dir($relative_dir, @path);
 $abs_file                        = File::Where->where_file($relative_file);
 $abs_file                        = File::Where->where_file($relative_file, \@path);
 $abs_file                        = File::Where->where_file($relative_file, @path);
 
 ($abs_file, $inc_path, $require) = File::Where->where_file($relative_file)
 ($abs_file, $inc_path, $require) = File::Where->where_file($relative_file, \@path)
 ($abs_file, $inc_path, $require) = File::Where->where_file($relative_file, @path)
 $abs_file                        = File::Where->where_pm($pm); 
 $abs_file                        = File::Where->where_pm($pm, \@path);
 $abs_file                        = File::Where->where_pm($pm, @path);
 ($abs_file, $inc_path, $require) = File::Where->where_pm($pm);
 ($abs_file, $inc_path, $require) = File::Where->where_pm($pm, \@path);
 ($abs_file, $inc_path, $require) = File::Where->where_pm($pm, @path);
 $abs_dir                         = File::Where->where_repository($repository);
 $abs_dir                         = File::Where->where_repository($repository, \@path);
 $abs_dir                         = File::Where->where_repository($repository, @path);
 ($abs_dir,  $inc_path, $rel_dir) = File::Where->where_repository($repository);
 ($abs_dir,  $inc_path, $rel_dir) = File::Where->where_repository($repository, \@path);
 ($abs_dir,  $inc_path, $rel_dir) = File::Where->where_repository($repository, @path);


DESCRIPTION

From time to time, an program needs to know the abolute file for a program module that has not been loaded. The File::Where module provides methods to find this information. For loaded files, using the hash %INC may perform better than using the methods in this module.


SUBROUTINES

is_module

 $program_module = is_module(@program_modules);

The is_module subroutine determines if a $module is present in a list of modules @modules. The detemination is case insensitive and only the leading characters are needed.

dir_pms

 @program_modules = dir_pms( $dir );

The dir_pms subroutine returns the @program_modules in directory $dir.

program_modules

 @program_modules = program_modules( $dir, '$file_flag', @dirs);

The program_modules subroutine returns the program_modules in the dir File::Spec-catdir($dir,@dirs) with an empty 'file_flag'; otherwise with a 'file_flag', $dir is a file specification and program_modules subroutine only uses the directory portion of $dir.

repository_pms

 @program_modules = repository_pms($repository);

The repository_pms returns the @program_modules in repository. A repository is the a program module name that corresponds to a directory. For example, a repository for File::Where is File.

pm2require subroutine

 $file = pm2require($pm_file)

The pm2require method/subroutine returns the file suitable for use in a Perl require for the $pm program module.

where subroutine

The where subroutine is the core subroutine call by where_file, where_dir, where_pm and where_repository.

When $no_file is absent, 0 or '', the where subroutine performs as established for the where_file subroutine; otherwise the where subroutine performs as established for the where_dir subroutine.

The differences is that the where syntax only accepts a reference to an array path while the where_dir and where_file accept both a reference to an array path and an array path.

where_dir subroutine

When $nofile exists and is non-zero, the find_in_include method/subroutine looks for the $relative_dir under one of the directories in the @path (@INC path if @path is '' or 0) in the order listed in @path or @INC. When find_in_include finds the directory, it returns the absolute file $absolute_dir and the directory $path where it found $relative_dir when the usage calls for an array return; otherwise, the absolute directory $absolute_dir.

When the @path list of directores exists and is not '' or 0, the where_dir subroutine/method searches the @path list of directories instead of the @INC list of directories.

where_file subroutine

When $nofile is '', 0 or absent, the find_in_include method/subroutine looks for the $relative_file in one of the directories in the @path (@INC path if @path is absent, '' or 0) in the order listed in @path or @INC. When find_in_include finds the file, it returns the absolute file $file_absolute and the directory $path where it found $file_relative when the usage calls for an array return; otherwise, the absolute file $file_absolute.

When the @path list of directores exists and is not '' or 0, the where_file subroutine/method searches the @path list of directories instead of the @INC list of directories.

where_pm subroutine

In an array context, the where_pm subroutine/method returns the $absolute_file, the directory $inc_path in @INC, and the relative $require_file for the first directory in @INC list of directories where it found the program module $pm; otherwise, it returns just the $absolute_file.

When the @path list of directores exists and is not '' or 0, the where_pm subroutine/method searches the @path list of directories instead of the @INC list of directories.

where_repository subroutine

An repository specifies the location of a number of program modules. For example, the repository for this program module, File::Where, is File::.

In an array context, the where_repository subroutine/method returns the $absolute_directory, the directory $inc_path in @INC for the first directory in @INC list of directories, and the relative directory of the repository where it found the $repository; otherwise, it returns just the $absolute_file.\ When where_repository cannot find a directory containing the $repository relative directory, where_repository pops the last directory off the $repository relative directory and trys again. If where_repository finds that $repository is empty, it returns emptys.

for the $repository; otherwise, it returns just the $absolute_directory.

When the @path list of directores exists and is not '' or 0, the where_repository subroutine/method searches the @path list of directories instead of the @INC list of directories.


REQUIREMENTS


=head1 DEMONSTRATION
 #########
 # perl Where.d
 ###

~~~~~~ Demonstration overview ~~~~~

The results from executing the Perl Code follow on the next lines as comments. For example,

 2 + 2
 # 4

~~~~~~ The demonstration follows ~~~~~

     use File::Spec;
     use File::Copy;
     use File::Path;
     use File::Package;
     my $fp = 'File::Package';
     my $uut = 'File::Where';
     my $loaded = '';
     # Use the test file as an example since know its absolute path
     #
     my $test_script_dir = cwd();
     chdir File::Spec->updir();
     chdir File::Spec->updir();
     my $include_dir = cwd();
     chdir $test_script_dir;
     my $OS = $^O;  # need to escape ^
     unless ($OS) {   # on some perls $^O is not defined
         require Config;
        $OS = $Config::Config{'osname'};
     } 
     $include_dir =~ s=/=\\=g if( $OS eq 'MSWin32');
     $test_script_dir =~ s=/=\\=g if( $OS eq 'MSWin32');
     # Put base directory as the first in the @INC path
     #
     my @restore_inc = @INC;
     my $relative_file = File::Spec->catfile('t', 'File', 'Where.pm'); 
     my $relative_dir1 = File::Spec->catdir('t', 'File');
     my $relative_dir2 = File::Spec->catdir('t', 'Jolly_Green_Giant');
     my $absolute_file1 = File::Spec->catfile($include_dir, 't', 'File', 'Where.pm');
     my $absolute_dir1A = File::Spec->catdir($include_dir, 't', 'File');
     my $absolute_dir1B = File::Spec->catdir($include_dir, 't');
     mkpath (File::Spec->catdir($test_script_dir, 't','File'));
     my $absolute_file2 = File::Spec->catfile($test_script_dir, 't', 'File', 'Where.pm');
     my $absolute_dir2A = File::Spec->catdir($include_dir, 't', 'File', 't', 'File');
     my $absolute_dir2B = File::Spec->catdir($include_dir, 't', 'File', 't');
     #####
     # If doing a target site install, blib going to be up front in @INC
     # Locate the include directory with high probability of having the
     # first File::Where in the include path.
     #
     # Really not important that that cheapen test somewhat by doing a quasi
     # where search in that using this to test for a boundary condition where
     # the class, 'File::Where', is the same as the program module 'File::Where
     # that the 'where' subroutine/method is locating.
     #
     my $absolute_dir_where = File::Spec->catdir($include_dir, 'lib');
     foreach (@INC) {
         if ($_ =~ /blib/) {
             $absolute_dir_where = $_ ;
             last;
         }
         elsif ($_ =~ /lib/) {
             $absolute_dir_where = $_ ;
             last;
         }
     }
     my $absolute_file_where = File::Spec->catfile($absolute_dir_where, 'File', 'Where.pm');
     my @inc2 = ($test_script_dir, @INC);  # another way to do unshift
     copy $absolute_file1,$absolute_file2;
     unshift @INC, $include_dir;
     my (@actual,$actual); # use for array and scalar context
 ##################
 # Load UUT
 #
 my $errors = $fp->load_package('File::Where', 'where_pm')
 $errors
 # ''
 #
 ##################
 # pm2require
 #
 $actual = $uut->pm2require( 'File::Where')
 # 'File\Where.pm'
 #
 ##################
 # program modules('_Drivers_')
 #
 [my @drivers = sort $uut->program_modules( '_Drivers_' )]
 # [
 #          'Driver',
 #          'Generate',
 #          'IO'
 #        ]
 #
 ##################
 # is_module('dri', Driver Generate IO)
 #
 $uut->is_module('dri', @drivers )
 # 'Driver'
 #
 ##################
 # repository_pms('t::File::_Drivers_')
 #
 [@drivers = sort $uut->repository_pms( 't::File::_Drivers_' )]
 # [
 #          'Driver',
 #          'Generate',
 #          'IO'
 #        ]
 #
 ##################
 # dir_pms( '_Drivers_' )
 #
 [@drivers = sort $uut->dir_pms( '_Drivers_' )]
 # [
 #          'Driver',
 #          'Generate',
 #          'IO'
 #        ]
 #
 ##################
 # where finding a file, array context, path absent
 #
 [@actual = $uut->where($relative_file)]
 # [
 #          'E:\User\SoftwareDiamonds\installation\t\File\Where.pm',
 #          'E:\User\SoftwareDiamonds\installation',
 #          't\File\Where.pm'
 #        ]
 #
 ##################
 # where finding a file, scalar context, path absent
 #
 $actual = $uut->where($relative_file)
 # 'E:\User\SoftwareDiamonds\installation\t\File\Where.pm'
 #
 ##################
 # where finding a file, array context, array reference path
 #
 [@actual = $uut->where($relative_file, [$test_script_dir, $include_dir])]
 # [
 #          'E:\User\SoftwareDiamonds\installation\t\File\t\File\Where.pm',
 #          'E:\User\SoftwareDiamonds\installation\t\File',
 #          't\File\Where.pm'
 #        ]
 #
 ##################
 # where finding a dir, array context, path absent
 #
 [@actual = $uut->where($relative_dir1, '', 'nofile')]
 # [
 #          'E:\User\SoftwareDiamonds\installation\t\File',
 #          'E:\User\SoftwareDiamonds\installation',
 #          't\File'
 #        ]
 #
 ##################
 # where finding a dir, scalar context, path absent
 #
 $actual = $uut->where($relative_file, '', 'nofile')
 # 'E:\User\SoftwareDiamonds\installation\t\File'
 #
 ##################
 # where finding a dir, array context, array reference path
 #
 [@actual = $uut->where($relative_dir2, \@inc2, 'nofile')]
 # [
 #          'E:\User\SoftwareDiamonds\installation\t\File\t',
 #          'E:\User\SoftwareDiamonds\installation\t\File',
 #          't'
 #        ]
 #
 ##################
 # where finding a dir, scalar context, array reference path
 #
 $actual = $uut->where('t', [$test_script_dir,@INC], 'nofile')
 # 'E:\User\SoftwareDiamonds\installation\t\File\t'
 #
 ##################
 # where_file, array context, path absent
 #
 [@actual = $uut->where_file($relative_file)]
 # [
 #          'E:\User\SoftwareDiamonds\installation\t\File\Where.pm',
 #          'E:\User\SoftwareDiamonds\installation',
 #          't\File\Where.pm'
 #        ]
 #
 ##################
 # where_file, scalar context, array path
 #
 $actual = $uut->where_file($relative_file, $test_script_dir, $include_dir)
 # 'E:\User\SoftwareDiamonds\installation\t\File\t\File\Where.pm'
 #
 ##################
 # where_dir, array context, array reference
 #
 [@actual = $uut->where_dir($relative_dir1, \@inc2)]
 # [
 #          'E:\User\SoftwareDiamonds\installation\t\File\t\File',
 #          'E:\User\SoftwareDiamonds\installation\t\File',
 #          't\File'
 #        ]
 #
 ##################
 # where_dir, array context, array reference
 #
 [@actual = $uut->where_dir($relative_dir2, $test_script_dir)]
 # [
 #          'E:\User\SoftwareDiamonds\installation\t\File\t',
 #          'E:\User\SoftwareDiamonds\installation\t\File',
 #          't'
 #        ]
 #
 ##################
 # where_dir, scalar context, path absent
 #
 $actual = $uut->where_dir($relative_file)
 # 'E:\User\SoftwareDiamonds\installation\t\File'
 #
 ##################
 # where_pm, array context, path absent
 #
 [@actual= $uut->where_pm( 't::File::Where' )]
 # [
 #          'E:\User\SoftwareDiamonds\installation\t\File\Where.pm',
 #          'E:\User\SoftwareDiamonds\installation',
 #          't\File\Where.pm'
 #        ]
 #
 ##################
 # where_pm, scalar context, array path
 #
 $actual = $uut->where_pm( 't::File::Where', @inc2)
 # 'E:\User\SoftwareDiamonds\installation\t\File\t\File\Where.pm'
 #
 ##################
 # where_pm, File::Where boundary case
 #
 $actual = $uut->where_pm( 'File::Where')
 # 'E:\User\SoftwareDiamonds\installation\lib\File\Where.pm'
 #
 ##################
 # where_pm subroutine, array context, array reference path
 #
 [@actual= $uut->where_pm( 't::File::Where', [$test_script_dir])]
 # [
 #          'E:\User\SoftwareDiamonds\installation\t\File\t\File\Where.pm',
 #          'E:\User\SoftwareDiamonds\installation\t\File',
 #          't\File\Where.pm'
 #        ]
 #
 ##################
 # where_repository, array context, path absent
 #
 [@actual= $uut->where_repository( 't::File' )]
 # [
 #          'E:\User\SoftwareDiamonds\installation\t\File',
 #          'E:\User\SoftwareDiamonds\installation',
 #          't\File'
 #        ]
 #
 ##################
 # where_repository, scalar context, array path
 #
 $actual = $uut->where_repository( 't::File', @inc2)
 # 'E:\User\SoftwareDiamonds\installation\t\File\t\File'
 #
 ##################
 # where_repository, array context, array reference path
 #
 [@actual= $uut->where_repository( 't::Jolly_Green_Giant', [$test_script_dir])]
 # [
 #          'E:\User\SoftwareDiamonds\installation\t\File\t',
 #          'E:\User\SoftwareDiamonds\installation\t\File',
 #          't'
 #        ]
 #
    @INC = @restore_inc; #restore @INC;
    rmtree 't';


QUALITY ASSURANCE

Running the test script Where.t verifies the requirements for this module.

The tmake.pl cover script for Test::STDmaker automatically generated the Where.t test script, Where.d demo script, and t::Data::Where program module POD, from the t::Data::Where program module contents. The t::Data::Where program module is in the distribution file Data-Where-$VERSION.tar.gz.


NOTES

Author

The holder of the copyright and maintainer is

<support@SoftwareDiamonds.com>

Copyright Notice

Copyrighted (c) 2002 Software Diamonds

All Rights Reserved

Binding Requirements Notice

Binding requirements are indexed with the pharse 'shall[dd]' where dd is an unique number for each header section. This conforms to standard federal government practices, STD490A 3.2.3.6. In accordance with the License, Software Diamonds is not liable for any requirement, binding or otherwise.

License

Software Diamonds permits the redistribution and use in source and binary forms, with or without modification, provided that the following conditions are met:

  1. Redistributions of source code must retain the above copyright notice, this list of conditions and the following disclaimer.

  2. Redistributions in binary form must reproduce the above copyright notice, this list of conditions and the following disclaimer in the documentation and/or other materials provided with the distribution.

SOFTWARE DIAMONDS, http://www.softwarediamonds.com, PROVIDES THIS SOFTWARE 'AS IS' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL SOFTWARE DIAMONDS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING USE OF THIS SOFTWARE, EVEN IF ADVISED OF NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE POSSIBILITY OF SUCH DAMAGE.


SEE ALSO

Docs::Site_SVD::Data_Where
Test::STDmaker