53 lines
1 KiB
Perl
53 lines
1 KiB
Perl
package SelectSaver;
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=head1 NAME
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SelectSaver - save and restore selected file handle
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=head1 SYNOPSIS
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use SelectSaver;
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{
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my $saver = new SelectSaver(FILEHANDLE);
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# FILEHANDLE is selected
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}
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# previous handle is selected
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{
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my $saver = new SelectSaver;
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# new handle may be selected, or not
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}
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# previous handle is selected
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=head1 DESCRIPTION
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A C<SelectSaver> object contains a reference to the file handle that
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was selected when it was created. If its C<new> method gets an extra
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parameter, then that parameter is selected; otherwise, the selected
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file handle remains unchanged.
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When a C<SelectSaver> is destroyed, it re-selects the file handle
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that was selected when it was created.
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=cut
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require 5.000;
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use Carp;
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use Symbol;
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sub new {
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@_ >= 1 && @_ <= 2 or croak 'usage: new SelectSaver [FILEHANDLE]';
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my $fh = select;
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my $self = bless [$fh], $_[0];
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select qualify($_[1], caller) if @_ > 1;
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$self;
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}
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sub DESTROY {
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my $this = $_[0];
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select $$this[0];
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}
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1;
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