perl/lib/SelectSaver.pm

package SelectSaver;

our $VERSION = '1.01';

=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 $self = $_[0];
    select $$self;
}

1;
Revision:	1.1
Committed:	Thu Jun 30 14:27:08 2005 UTC (21 years, 4 months ago) by root
Branch:	MAIN
CVS Tags:	PERL-5-8-7, HEAD
Branch point for:	PERL
Log Message:	* empty log message *
#	User	Rev	Content
1	root	1.1	package SelectSaver;
2
3			our $VERSION = '1.01';
4
5			=head1 NAME
6
7			SelectSaver - save and restore selected file handle
8
9			=head1 SYNOPSIS
10
11			use SelectSaver;
12
13			{
14			my $saver = new SelectSaver(FILEHANDLE);
15			# FILEHANDLE is selected
16			}
17			# previous handle is selected
18
19			{
20			my $saver = new SelectSaver;
21			# new handle may be selected, or not
22			}
23			# previous handle is selected
24
25			=head1 DESCRIPTION
26
27			A C<SelectSaver> object contains a reference to the file handle that
28			was selected when it was created. If its C<new> method gets an extra
29			parameter, then that parameter is selected; otherwise, the selected
30			file handle remains unchanged.
31
32			When a C<SelectSaver> is destroyed, it re-selects the file handle
33			that was selected when it was created.
34
35			=cut
36
37			require 5.000;
38			use Carp;
39			use Symbol;
40
41			sub new {
42			@_ >= 1 && @_ <= 2 or croak 'usage: new SelectSaver [FILEHANDLE]';
43			my $fh = select;
44			my $self = bless \$fh, $_[0];
45			select qualify($_[1], caller) if @_ > 1;
46			$self;
47			}
48
49			sub DESTROY {
50			my $self = $_[0];
51			select $$self;
52			}
53
54			1;