FM / perl5

/usr/share/perl5

Name	Size	Mode	Actions
B/	-	0755	rm
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Config/	-	0755	rm
DBM_Filter/	-	0755	rm
encoding/	-	0755	rm
ExtUtils/	-	0755	rm
File/	-	0755	rm
Getopt/	-	0755	rm
I18N/	-	0755	rm
IPC/	-	0755	rm
Math/	-	0755	rm
Net/	-	0755	rm
overload/	-	0755	rm
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pod/	-	0755	rm
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Text/	-	0755	rm
Thread/	-	0755	rm
Tie/	-	0755	rm
Time/	-	0755	rm
Unicode/	-	0755	rm
unicore/	-	0755	rm
URI/	-	0755	rm
User/	-	0755	rm
vendor_perl/	-	0755	rm
warnings/	-	0755	rm
AnyDBM_File.pm	2618	0644	edit dl rm
AutoLoader.pm	15797	0644	edit dl rm
AutoSplit.pm	19637	0644	edit dl rm
autouse.pm	4238	0644	edit dl rm
base.pm	10980	0644	edit dl rm
Benchmark.pm	31025	0644	edit dl rm
blib.pm	2086	0644	edit dl rm
bytes.pm	3754	0644	edit dl rm
bytes_heavy.pl	758	0644	edit dl rm
charnames.pm	20867	0644	edit dl rm
CORE.pod	3188	0644	edit dl rm
DB.pm	18922	0644	edit dl rm
DBM_Filter.pm	14385	0644	edit dl rm
deprecate.pm	3079	0644	edit dl rm
diagnostics.pm	19038	0644	edit dl rm
DirHandle.pm	1556	0644	edit dl rm
Dumpvalue.pm	17556	0644	edit dl rm
dumpvar.pl	15555	0644	edit dl rm
English.pm	4761	0644	edit dl rm
feature.pm	17085	0644	edit dl rm
fields.pm	9489	0644	edit dl rm
FileCache.pm	5572	0644	edit dl rm
FileHandle.pm	6784	0644	edit dl rm
filetest.pm	4003	0644	edit dl rm
FindBin.pm	4561	0644	edit dl rm
if.pm	3340	0644	edit dl rm
integer.pm	3254	0644	edit dl rm
Internals.pod	2576	0644	edit dl rm
less.pm	3204	0644	edit dl rm
locale.pm	4855	0644	edit dl rm
meta_notation.pm	2117	0644	edit dl rm
NEXT.pm	18846	0644	edit dl rm
overload.pm	53314	0644	edit dl rm
overloading.pm	1808	0644	edit dl rm
perl5db.pl	316420	0644	edit dl rm
PerlIO.pm	10459	0644	edit dl rm
Safe.pm	25082	0644	edit dl rm
SelectSaver.pm	1076	0644	edit dl rm
sigtrap.pm	7606	0644	edit dl rm
sort.pm	6081	0644	edit dl rm
strict.pm	4738	0644	edit dl rm
subs.pm	848	0644	edit dl rm
Symbol.pm	4799	0644	edit dl rm
Thread.pm	8287	0644	edit dl rm
UNIVERSAL.pm	6594	0644	edit dl rm
URI.pm	34790	0644	edit dl rm
utf8.pm	9116	0644	edit dl rm
utf8_heavy.pl	31615	0644	edit dl rm
vars.pm	2414	0644	edit dl rm
vmsish.pm	4313	0644	edit dl rm
warnings.pm	44756	0644	edit dl rm
XSLoader.pm	11267	0644	edit dl rm
_charnames.pm	33166	0644	edit dl rm

Edit: /usr/share/perl5/if.pm (3340B)

package if;

$VERSION = '0.0606';

sub work {
  my $method = shift() ? 'import' : 'unimport';
  unless (@_ >= 2) {
    my $type = ($method eq 'import') ? 'use' : 'no';
    die "Too few arguments to '$type if' (some code returning an empty list in list context?)"
  }
  return unless shift;		# CONDITION

my $p = $_[0];		# PACKAGE
  (my $file = "$p.pm") =~ s!::!/!g;
  require $file;		# Works even if $_[0] is a keyword (like open)
  my $m = $p->can($method);
  goto &$m if $m;
}

sub import   { shift; unshift @_, 1; goto &work }
sub unimport { shift; unshift @_, 0; goto &work }

1;
__END__

=head1 NAME

if - C<use> a Perl module if a condition holds (also can C<no> a module)

=head1 SYNOPSIS

use if CONDITION, MODULE => ARGUMENTS;
  no if CONDITION, MODULE => ARGUMENTS;

=head1 DESCRIPTION

The C<if> module is used to conditionally load or unload another module.
The construct

use if CONDITION, MODULE => ARGUMENTS;

will load MODULE only if CONDITION evaluates to true.
The above statement has no effect unless C<CONDITION> is true.
If the CONDITION does evaluate to true, then the above line has
the same effect as:

use MODULE ARGUMENTS;

The use of C<< => >> above provides necessary quoting of C<MODULE>.
If you don't use the fat comma (eg you don't have any ARGUMENTS),
then you'll need to quote the MODULE.

=head2 EXAMPLES

The following line is taken from the testsuite for L<File::Map>:

use if $^O ne 'MSWin32', POSIX => qw/setlocale LC_ALL/;

If run on any operating system other than Windows,
this will import the functions C<setlocale> and C<LC_ALL> from L<POSIX>.
On Windows it does nothing.

The following is used to L<deprecate> core modules beyond a certain version of Perl:

use if $] > 5.016, 'deprecate';

This line is taken from L<Text::Soundex> 3.04,
and marks it as deprecated beyond Perl 5.16.
If you C<use Text::Soundex> in Perl 5.18, for example,
and you have used L<warnings>,
then you'll get a warning message
(the deprecate module looks to see whether the
calling module was C<use>'d from a core library directory,
and if so, generates a warning),
unless you've installed a more recent version of L<Text::Soundex> from CPAN.

You can also specify to NOT use something:

no if $] ge 5.021_006, warnings => "locale";

This warning category was added in the specified Perl version (a development
release).  Without the C<'if'>, trying to use it in an earlier release would
generate an unknown warning category error.

=head1 BUGS

The current implementation does not allow specification of the
required version of the module.

=head1 SEE ALSO

L<Module::Requires> can be used to conditionally load one or modules,
with constraints based on the version of the module.
Unlike C<if> though, L<Module::Requires> is not a core module.

L<Module::Load::Conditional> provides a number of functions you can use to
query what modules are available, and then load one or more of them at runtime.

L<provide> can be used to select one of several possible modules to load,
based on what version of Perl is running.

=head1 AUTHOR

Ilya Zakharevich L<mailto:ilyaz@cpan.org>.

=head1 COPYRIGHT AND LICENCE

This is free software; you can redistribute it and/or modify it under
the same terms as the Perl 5 programming language system itself.

=cut

package if; $VERSION = '0.0606'; sub work { my $method = shift() ? 'import' : 'unimport'; unless (@_ >= 2) { my $type = ($method eq 'import') ? 'use' : 'no'; die "Too few arguments to '$type if' (some code returning an empty list in list context?)" } return unless shift; # CONDITION my $p = $_[0]; # PACKAGE (my $file = "$p.pm") =~ s!::!/!g; require $file; # Works even if $_[0] is a keyword (like open) my $m = $p->can($method); goto &$m if $m; } sub import { shift; unshift @_, 1; goto &work } sub unimport { shift; unshift @_, 0; goto &work } 1; __END__ =head1 NAME if - C a Perl module if a condition holds (also can C a module) =head1 SYNOPSIS use if CONDITION, MODULE => ARGUMENTS; no if CONDITION, MODULE => ARGUMENTS; =head1 DESCRIPTION The C module is used to conditionally load or unload another module. The construct use if CONDITION, MODULE => ARGUMENTS; will load MODULE only if CONDITION evaluates to true. The above statement has no effect unless C is true. If the CONDITION does evaluate to true, then the above line has the same effect as: use MODULE ARGUMENTS; The use of C<< => >> above provides necessary quoting of C. If you don't use the fat comma (eg you don't have any ARGUMENTS), then you'll need to quote the MODULE. =head2 EXAMPLES The following line is taken from the testsuite for L: use if $^O ne 'MSWin32', POSIX => qw/setlocale LC_ALL/; If run on any operating system other than Windows, this will import the functions C and C from L. On Windows it does nothing. The following is used to L core modules beyond a certain version of Perl: use if $] > 5.016, 'deprecate'; This line is taken from L 3.04, and marks it as deprecated beyond Perl 5.16. If you C in Perl 5.18, for example, and you have used L, then you'll get a warning message (the deprecate module looks to see whether the calling module was C'd from a core library directory, and if so, generates a warning), unless you've installed a more recent version of L from CPAN. You can also specify to NOT use something: no if $] ge 5.021_006, warnings => "locale"; This warning category was added in the specified Perl version (a development release). Without the C<'if'>, trying to use it in an earlier release would generate an unknown warning category error. =head1 BUGS The current implementation does not allow specification of the required version of the module. =head1 SEE ALSO L can be used to conditionally load one or modules, with constraints based on the version of the module. Unlike C though, L is not a core module. L provides a number of functions you can use to query what modules are available, and then load one or more of them at runtime. L can be used to select one of several possible modules to load, based on what version of Perl is running. =head1 AUTHOR Ilya Zakharevich L. =head1 COPYRIGHT AND LICENCE This software is copyright (c) 2002 by Ilya Zakharevich. This is free software; you can redistribute it and/or modify it under the same terms as the Perl 5 programming language system itself. =cut