Initial commit of OpenSPARC T2 design and verification files.

[OpenSPARC-T2-DV] / tools / perl-5.8.0 / lib / 5.8.0 / SelectSaver.pm

package SelectSaver;

our $VERSION = '1.00';

=head1 NAME

SelectSaver - save and restore selected file handle

=head1 SYNOPSIS

   use SelectSaver;

   {
      my $saver = new SelectSaver(FILEHANDLE);
      # FILEHANDLE is selected
   }
   # previous handle is selected

   {
      my $saver = new SelectSaver;
      # new handle may be selected, or not
   }
   # previous handle is selected

=head1 DESCRIPTION

A C<SelectSaver> object contains a reference to the file handle that
was selected when it was created.  If its C<new> method gets an extra
parameter, then that parameter is selected; otherwise, the selected
file handle remains unchanged.

When a C<SelectSaver> is destroyed, it re-selects the file handle
that was selected when it was created.

=cut

require 5.000;
use Carp;
use Symbol;

sub new {
   @_ >= 1 && @_ <= 2 or croak 'usage: new SelectSaver [FILEHANDLE]';
   my $fh = select;
   my $self = bless [$fh], $_[0];
   select qualify($_[1], caller) if @_ > 1;
   $self;
}

sub DESTROY {
   my $this = $_[0];
   select $$this[0];
}

1;