Commit | Line | Data |
6be43b56 |
1 | package Devel::PeekPoke::Constants; |
2 | |
3 | use strict; |
4 | use warnings; |
5 | |
6 | use Config; |
7 | |
8 | BEGIN { |
9 | my $ptr_size = $Config{ptrsize}; |
10 | eval "sub PTR_SIZE () { $ptr_size }"; |
11 | |
12 | my $ptr_pack_type = do { |
13 | if ($ptr_size == 4) { |
14 | 'L' |
15 | } |
16 | elsif ($ptr_size == 8) { |
17 | 'Q' |
18 | } |
19 | else { |
20 | die "Unsupported \$Config{ptrsize}: $ptr_size\n"; |
21 | } |
22 | }; |
23 | eval "sub PTR_PACK_TYPE () { $ptr_pack_type }"; |
24 | |
25 | my $big_endian = do { |
26 | my $ivnums = join '', (1 .. $Config{ivsize}); |
27 | if ($Config{byteorder} eq $ivnums ) { |
28 | 0 |
29 | } |
30 | elsif ($Config{byteorder} eq scalar reverse $ivnums ) { |
31 | 1 |
32 | } |
33 | else { |
34 | die "Weird byteorder: $Config{byteorder}\n"; |
35 | } |
36 | }; |
37 | eval "sub BIG_ENDIAN () { $big_endian }"; |
38 | } |
39 | |
40 | use base 'Exporter'; |
41 | our @EXPORT_OK = (qw/PTR_SIZE PTR_PACK_TYPE BIG_ENDIAN/); |
42 | |
43 | =head1 NAME |
44 | |
45 | Devel::PeekPoke::Constants - Some convenience constants based on your machine |
46 | |
47 | =head1 DESRIPTION |
48 | |
49 | This module provides some convenience constants based on your machine. It |
50 | provides the following constants (exportable on request) |
51 | |
52 | =head2 PTR_SIZE |
53 | |
54 | The size of your pointer, equivalent to L<$Config::ptr_size|Config>. |
55 | |
56 | =head2 PTR_PACK_TYPE |
57 | |
58 | The L<pack|perlfunc/pack> template type suitable for L</PTR_SIZE> pointers. |
59 | Either C<L> (32 bit) or C<Q> (64 bit). |
60 | |
61 | =head2 BIG_ENDIAN |
62 | |
63 | An indicator whether your system is big-endian (constant is set to C<1>) or |
64 | little-endian (constant is set to C<0>). |
65 | |
66 | =head1 COPYRIGHT |
67 | |
68 | See L<Devel::PeekPoke/COPYRIGHT>. |
69 | |
70 | =head1 LICENSE |
71 | |
72 | See L<Devel::PeekPoke/LICENSE>. |
73 | |
74 | =cut |
75 | |
76 | 1; |