if.pm

来自「SinFP是一种新的识别对方计算机操作系统类型的工具」· PM 代码 · 共 50 行

package if;

use vars qw($VERSION);
$VERSION = '0.01';

sub work {
  my $method = shift() ? 'import' : 'unimport';
  return unless shift;		# CONDITION
  my $p = shift;		# PACKAGE
  eval "require $p" or die;	# Adds .pm etc if needed
  $p->$method(@_) if $p->can($method);
}

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

=head1 SYNOPSIS

  use if CONDITION, MODULE => ARGUMENTS;

=head1 DESCRIPTION

The construct

  use if CONDITION, MODULE => ARGUMENTS;

has no effect unless C<CONDITION> is true.  In this case the effect is
the same as of

  use MODULE ARGUMENTS;

=head1 BUGS

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

=head1 AUTHOR

Ilya Zakharevich L<mailto:[e-mail]>.

=cut