mirror of
https://git.savannah.gnu.org/git/parallel.git
synced 2024-12-23 13:17:54 +00:00
55 lines
1.1 KiB
Perl
55 lines
1.1 KiB
Perl
package SelectSaver;
|
|
|
|
our $VERSION = '1.02';
|
|
|
|
=head1 NAME
|
|
|
|
SelectSaver - save and restore selected file handle
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
use SelectSaver;
|
|
|
|
{
|
|
my $saver = SelectSaver->new(FILEHANDLE);
|
|
# FILEHANDLE is selected
|
|
}
|
|
# previous handle is selected
|
|
|
|
{
|
|
my $saver = SelectSaver->new;
|
|
# 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: SelectSaver->new( [FILEHANDLE] )';
|
|
my $fh = select;
|
|
my $self = bless \$fh, $_[0];
|
|
select qualify($_[1], caller) if @_ > 1;
|
|
$self;
|
|
}
|
|
|
|
sub DESTROY {
|
|
my $self = $_[0];
|
|
select $$self;
|
|
}
|
|
|
|
1;
|