xref: /openbsd-src/gnu/usr.bin/perl/lib/DirHandle.pm (revision 5759b3d249badf144a6240f7eec4dcf9df003e6b)
1package DirHandle;
2
3our $VERSION = '1.05';
4
5=head1 NAME
6
7DirHandle - (obsolete) supply object methods for directory handles
8
9=head1 SYNOPSIS
10
11    # recommended approach since Perl 5.6: do not use DirHandle
12    if (opendir my $d, '.') {
13        while (readdir $d) { something($_); }
14        rewind $d;
15        while (readdir $d) { something_else($_); }
16    }
17
18    # how you would use this module if you were going to
19    use DirHandle;
20    if (my $d = DirHandle->new(".")) {
21        while (defined($_ = $d->read)) { something($_); }
22        $d->rewind;
23        while (defined($_ = $d->read)) { something_else($_); }
24    }
25
26=head1 DESCRIPTION
27
28B<There is no reason to use this module nowadays.>
29
30The C<DirHandle> method provide an alternative interface to the
31opendir(), closedir(), readdir(), and rewinddir() functions.
32
33Up to Perl 5.5, opendir() could not autovivify a directory handle from
34C<undef>, so using a lexical handle required using a function from L<Symbol>
35to create an anonymous glob, which took a separate step.
36C<DirHandle> encapsulates this, which allowed cleaner code than opendir().
37Since Perl 5.6, opendir() alone has been all you need for lexical handles.
38
39=cut
40
41require 5.000;
42use Carp;
43use Symbol;
44
45sub new {
46    @_ >= 1 && @_ <= 2 or croak 'usage: DirHandle->new( [DIRNAME] )';
47    my $class = shift;
48    my $dh = gensym;
49    if (@_) {
50	DirHandle::open($dh, $_[0])
51	    or return undef;
52    }
53    bless $dh, $class;
54}
55
56sub DESTROY {
57    my ($dh) = @_;
58    # Don't warn about already being closed as it may have been closed
59    # correctly, or maybe never opened at all.
60    local($., $@, $!, $^E, $?);
61    no warnings 'io';
62    closedir($dh);
63}
64
65sub open {
66    @_ == 2 or croak 'usage: $dh->open(DIRNAME)';
67    my ($dh, $dirname) = @_;
68    opendir($dh, $dirname);
69}
70
71sub close {
72    @_ == 1 or croak 'usage: $dh->close()';
73    my ($dh) = @_;
74    closedir($dh);
75}
76
77sub read {
78    @_ == 1 or croak 'usage: $dh->read()';
79    my ($dh) = @_;
80    readdir($dh);
81}
82
83sub rewind {
84    @_ == 1 or croak 'usage: $dh->rewind()';
85    my ($dh) = @_;
86    rewinddir($dh);
87}
88
891;
90