1package IO::Compress::Gzip::Constants;
2
3use strict ;
4use warnings;
5use bytes;
6
7require Exporter;
8
9our ($VERSION, @ISA, @EXPORT, %GZIP_OS_Names);
10our ($GZIP_FNAME_INVALID_CHAR_RE, $GZIP_FCOMMENT_INVALID_CHAR_RE);
11
12$VERSION = '2.212';
13
14@ISA = qw(Exporter);
15
16@EXPORT= qw(
17
18    GZIP_ID_SIZE
19    GZIP_ID1
20    GZIP_ID2
21
22    GZIP_FLG_DEFAULT
23    GZIP_FLG_FTEXT
24    GZIP_FLG_FHCRC
25    GZIP_FLG_FEXTRA
26    GZIP_FLG_FNAME
27    GZIP_FLG_FCOMMENT
28    GZIP_FLG_RESERVED
29
30    GZIP_CM_DEFLATED
31
32    GZIP_MIN_HEADER_SIZE
33    GZIP_TRAILER_SIZE
34
35    GZIP_MTIME_DEFAULT
36    GZIP_XFL_DEFAULT
37    GZIP_FEXTRA_HEADER_SIZE
38    GZIP_FEXTRA_MAX_SIZE
39    GZIP_FEXTRA_SUBFIELD_HEADER_SIZE
40    GZIP_FEXTRA_SUBFIELD_ID_SIZE
41    GZIP_FEXTRA_SUBFIELD_LEN_SIZE
42    GZIP_FEXTRA_SUBFIELD_MAX_SIZE
43
44    $GZIP_FNAME_INVALID_CHAR_RE
45    $GZIP_FCOMMENT_INVALID_CHAR_RE
46
47    GZIP_FHCRC_SIZE
48
49    GZIP_ISIZE_MAX
50    GZIP_ISIZE_MOD_VALUE
51
52
53    GZIP_NULL_BYTE
54
55    GZIP_OS_DEFAULT
56
57    %GZIP_OS_Names
58
59    GZIP_MINIMUM_HEADER
60
61    );
62
63# Constant names derived from RFC 1952
64
65use constant GZIP_ID_SIZE                     => 2 ;
66use constant GZIP_ID1                         => 0x1F;
67use constant GZIP_ID2                         => 0x8B;
68
69use constant GZIP_MIN_HEADER_SIZE             => 10 ;# minimum gzip header size
70use constant GZIP_TRAILER_SIZE                => 8 ;
71
72
73use constant GZIP_FLG_DEFAULT                 => 0x00 ;
74use constant GZIP_FLG_FTEXT                   => 0x01 ;
75use constant GZIP_FLG_FHCRC                   => 0x02 ; # called CONTINUATION in gzip
76use constant GZIP_FLG_FEXTRA                  => 0x04 ;
77use constant GZIP_FLG_FNAME                   => 0x08 ;
78use constant GZIP_FLG_FCOMMENT                => 0x10 ;
79#use constant GZIP_FLG_ENCRYPTED              => 0x20 ; # documented in gzip sources
80use constant GZIP_FLG_RESERVED                => (0x20 | 0x40 | 0x80) ;
81
82use constant GZIP_XFL_DEFAULT                 => 0x00 ;
83
84use constant GZIP_MTIME_DEFAULT               => 0x00 ;
85
86use constant GZIP_FEXTRA_HEADER_SIZE          => 2 ;
87use constant GZIP_FEXTRA_MAX_SIZE             => 0xFFFF ;
88use constant GZIP_FEXTRA_SUBFIELD_ID_SIZE     => 2 ;
89use constant GZIP_FEXTRA_SUBFIELD_LEN_SIZE    => 2 ;
90use constant GZIP_FEXTRA_SUBFIELD_HEADER_SIZE => GZIP_FEXTRA_SUBFIELD_ID_SIZE +
91                                                 GZIP_FEXTRA_SUBFIELD_LEN_SIZE;
92use constant GZIP_FEXTRA_SUBFIELD_MAX_SIZE    => GZIP_FEXTRA_MAX_SIZE -
93                                                 GZIP_FEXTRA_SUBFIELD_HEADER_SIZE ;
94
95
96if (ord('A') == 193)
97{
98    # EBCDIC
99    $GZIP_FNAME_INVALID_CHAR_RE = '[\x00-\x3f\xff]';
100    $GZIP_FCOMMENT_INVALID_CHAR_RE = '[\x00-\x0a\x11-\x14\x16-\x3f\xff]';
101
102}
103else
104{
105    $GZIP_FNAME_INVALID_CHAR_RE       =  '[\x00-\x1F\x7F-\x9F]';
106    $GZIP_FCOMMENT_INVALID_CHAR_RE    =  '[\x00-\x09\x11-\x1F\x7F-\x9F]';
107}
108
109use constant GZIP_FHCRC_SIZE        => 2 ; # aka CONTINUATION in gzip
110
111use constant GZIP_CM_DEFLATED       => 8 ;
112
113use constant GZIP_NULL_BYTE         => "\x00";
114use constant GZIP_ISIZE_MAX         => 0xFFFFFFFF ;
115use constant GZIP_ISIZE_MOD_VALUE   => GZIP_ISIZE_MAX + 1 ;
116
117# OS Names sourced from http://www.gzip.org/format.txt
118
119use constant GZIP_OS_DEFAULT=> 0xFF ;
120%GZIP_OS_Names = (
121    0   => 'MS-DOS',
122    1   => 'Amiga',
123    2   => 'VMS',
124    3   => 'Unix',
125    4   => 'VM/CMS',
126    5   => 'Atari TOS',
127    6   => 'HPFS (OS/2, NT)',
128    7   => 'Macintosh',
129    8   => 'Z-System',
130    9   => 'CP/M',
131    10  => 'TOPS-20',
132    11  => 'NTFS (NT)',
133    12  => 'SMS QDOS',
134    13  => 'Acorn RISCOS',
135    14  => 'VFAT file system (Win95, NT)',
136    15  => 'MVS',
137    16  => 'BeOS',
138    17  => 'Tandem/NSK',
139    18  => 'THEOS',
140    GZIP_OS_DEFAULT()   => 'Unknown',
141    ) ;
142
143use constant GZIP_MINIMUM_HEADER =>   pack("C4 V C C",
144        GZIP_ID1, GZIP_ID2, GZIP_CM_DEFLATED, GZIP_FLG_DEFAULT,
145        GZIP_MTIME_DEFAULT, GZIP_XFL_DEFAULT, GZIP_OS_DEFAULT) ;
146
147
1481;
149