Commit | Line | Data |
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c07a80fd | 1 | package SelectSaver; |
2 | ||
3 | =head1 NAME | |
4 | ||
5 | SelectSaver - save and restore selected file handle | |
6 | ||
7 | =head1 SYNOPSIS | |
8 | ||
9 | use SelectSaver; | |
10 | ||
11 | { | |
12 | my $saver = new SelectSaver(FILEHANDLE); | |
13 | # FILEHANDLE is selected | |
14 | } | |
15 | # previous handle is selected | |
16 | ||
17 | { | |
18 | my $saver = new SelectSaver; | |
19 | # new handle may be selected, or not | |
20 | } | |
21 | # previous handle is selected | |
22 | ||
23 | =head1 DESCRIPTION | |
24 | ||
25 | A C<SelectSaver> object contains a reference to the file handle that | |
26 | was selected when it was created. If its C<new> method gets an extra | |
27 | parameter, then that parameter is selected; otherwise, the selected | |
28 | file handle remains unchanged. | |
29 | ||
30 | When a C<SelectSaver> is destroyed, it re-selects the file handle | |
31 | that was selected when it was created. | |
32 | ||
33 | =cut | |
34 | ||
35 | require 5.000; | |
36 | use Carp; | |
37 | use Symbol; | |
38 | ||
39 | sub new { | |
40 | @_ >= 1 && @_ <= 2 or croak 'usage: new SelectSaver [FILEHANDLE]'; | |
37ec1aec SB |
41 | my $fh = select; |
42 | my $self = bless [$fh], $_[0]; | |
43 | select qualify($_[1], caller) if @_ > 1; | |
44 | $self; | |
c07a80fd | 45 | } |
46 | ||
47 | sub DESTROY { | |
48 | my $this = $_[0]; | |
49 | select $$this[0]; | |
50 | } | |
51 | ||
52 | 1; |