summaryrefslogtreecommitdiff
path: root/systems/texlive/tlnet/tlpkg/tlperl/lib/IO/Compress/Zip.pm
blob: 70b98b80d6e0e944cef82f630ed470fbd4ac1db7 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
1980
1981
1982
1983
1984
1985
1986
1987
1988
1989
1990
1991
1992
1993
1994
1995
1996
1997
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
2012
2013
2014
2015
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029
2030
2031
2032
2033
2034
2035
2036
2037
2038
2039
2040
2041
2042
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063
2064
2065
2066
2067
2068
2069
2070
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080
2081
2082
2083
2084
2085
2086
2087
2088
2089
2090
2091
2092
2093
2094
package IO::Compress::Zip ;

use strict ;
use warnings;
use bytes;

use IO::Compress::Base::Common  2.093 qw(:Status );
use IO::Compress::RawDeflate 2.093 ();
use IO::Compress::Adapter::Deflate 2.093 ;
use IO::Compress::Adapter::Identity 2.093 ;
use IO::Compress::Zlib::Extra 2.093 ;
use IO::Compress::Zip::Constants 2.093 ;

use File::Spec();
use Config;

use Compress::Raw::Zlib  2.093 (); 

BEGIN
{
    eval { require IO::Compress::Adapter::Bzip2 ; 
           import  IO::Compress::Adapter::Bzip2 2.093 ; 
           require IO::Compress::Bzip2 ; 
           import  IO::Compress::Bzip2 2.093 ; 
         } ;
         
    eval { require IO::Compress::Adapter::Lzma ; 
           import  IO::Compress::Adapter::Lzma 2.093 ; 
           require IO::Compress::Lzma ; 
           import  IO::Compress::Lzma 2.093 ; 
         } ;
}


require Exporter ;

our ($VERSION, @ISA, @EXPORT_OK, %EXPORT_TAGS, %DEFLATE_CONSTANTS, $ZipError);

$VERSION = '2.093';
$ZipError = '';

@ISA = qw(IO::Compress::RawDeflate Exporter);
@EXPORT_OK = qw( $ZipError zip ) ;
%EXPORT_TAGS = %IO::Compress::RawDeflate::DEFLATE_CONSTANTS ;

push @{ $EXPORT_TAGS{all} }, @EXPORT_OK ;

$EXPORT_TAGS{zip_method} = [qw( ZIP_CM_STORE ZIP_CM_DEFLATE ZIP_CM_BZIP2 ZIP_CM_LZMA)];
push @{ $EXPORT_TAGS{all} }, @{ $EXPORT_TAGS{zip_method} };

Exporter::export_ok_tags('all');

sub new
{
    my $class = shift ;

    my $obj = IO::Compress::Base::Common::createSelfTiedObject($class, \$ZipError);    
    $obj->_create(undef, @_);

}

sub zip
{
    my $obj = IO::Compress::Base::Common::createSelfTiedObject(undef, \$ZipError);    
    return $obj->_def(@_);
}

sub isMethodAvailable
{
    my $method = shift;
    
    # Store & Deflate are always available
    return 1
        if $method == ZIP_CM_STORE || $method == ZIP_CM_DEFLATE ;
        
    return 1 
        if $method == ZIP_CM_BZIP2 and 
           defined $IO::Compress::Adapter::Bzip2::VERSION;
           
    return 1
        if $method == ZIP_CM_LZMA and
           defined $IO::Compress::Adapter::Lzma::VERSION;
           
    return 0;       
}

sub beforePayload
{
    my $self = shift ;

    if (*$self->{ZipData}{Sparse} ) {
        my $inc = 1024 * 100 ;
        my $NULLS = ("\x00" x $inc) ;
        my $sparse = *$self->{ZipData}{Sparse} ;
        *$self->{CompSize}->add( $sparse );
        *$self->{UnCompSize}->add( $sparse );
        
        *$self->{FH}->seek($sparse, IO::Handle::SEEK_CUR);
        
        *$self->{ZipData}{CRC32} = Compress::Raw::Zlib::crc32($NULLS, *$self->{ZipData}{CRC32})
            for 1 .. int $sparse / $inc;
        *$self->{ZipData}{CRC32} = Compress::Raw::Zlib::crc32(substr($NULLS, 0,  $sparse % $inc), 
                                         *$self->{ZipData}{CRC32})
            if $sparse % $inc;
    }
}

sub mkComp
{
    my $self = shift ;
    my $got = shift ;

    my ($obj, $errstr, $errno) ;

    if (*$self->{ZipData}{Method} == ZIP_CM_STORE) {
        ($obj, $errstr, $errno) = IO::Compress::Adapter::Identity::mkCompObject(
                                                 $got->getValue('level'),
                                                 $got->getValue('strategy')
                                                 );
        *$self->{ZipData}{CRC32} = Compress::Raw::Zlib::crc32(undef);
    }
    elsif (*$self->{ZipData}{Method} == ZIP_CM_DEFLATE) {
        ($obj, $errstr, $errno) = IO::Compress::Adapter::Deflate::mkCompObject(
                                                 $got->getValue('crc32'),
                                                 $got->getValue('adler32'),
                                                 $got->getValue('level'),
                                                 $got->getValue('strategy')
                                                 );
    }
    elsif (*$self->{ZipData}{Method} == ZIP_CM_BZIP2) {
        ($obj, $errstr, $errno) = IO::Compress::Adapter::Bzip2::mkCompObject(
                                                $got->getValue('blocksize100k'),
                                                $got->getValue('workfactor'),
                                                $got->getValue('verbosity')
                                               );
        *$self->{ZipData}{CRC32} = Compress::Raw::Zlib::crc32(undef);
    }
    elsif (*$self->{ZipData}{Method} == ZIP_CM_LZMA) {
        ($obj, $errstr, $errno) = IO::Compress::Adapter::Lzma::mkRawZipCompObject($got->getValue('preset'),
                                                                                 $got->getValue('extreme'),
                                                                                 );
        *$self->{ZipData}{CRC32} = Compress::Raw::Zlib::crc32(undef);
    }

    return $self->saveErrorString(undef, $errstr, $errno)
       if ! defined $obj;

    if (! defined *$self->{ZipData}{SizesOffset}) {
        *$self->{ZipData}{SizesOffset} = 0;
        *$self->{ZipData}{Offset} = new U64 ;
    }

    *$self->{ZipData}{AnyZip64} = 0
        if ! defined  *$self->{ZipData}{AnyZip64} ;

    return $obj;    
}

sub reset
{
    my $self = shift ;

    *$self->{Compress}->reset();
    *$self->{ZipData}{CRC32} = Compress::Raw::Zlib::crc32('');

    return STATUS_OK;    
}

sub filterUncompressed
{
    my $self = shift ;

    if (*$self->{ZipData}{Method} == ZIP_CM_DEFLATE) {
        *$self->{ZipData}{CRC32} = *$self->{Compress}->crc32();
    }
    else {
        *$self->{ZipData}{CRC32} = Compress::Raw::Zlib::crc32(${$_[0]}, *$self->{ZipData}{CRC32});

    }
}

sub canonicalName
{
    # This sub is derived from Archive::Zip::_asZipDirName

    # Return the normalized name as used in a zip file (path
    # separators become slashes, etc.).
    # Will translate internal slashes in path components (i.e. on Macs) to
    # underscores.  Discards volume names.
    # When $forceDir is set, returns paths with trailing slashes 
    #
    # input         output
    # .             '.'
    # ./a           a
    # ./a/b         a/b
    # ./a/b/        a/b
    # a/b/          a/b
    # /a/b/         a/b
    # c:\a\b\c.doc  a/b/c.doc      # on Windows
    # "i/o maps:whatever"   i_o maps/whatever   # on Macs

    my $name      = shift;
    my $forceDir  = shift ;

    my ( $volume, $directories, $file ) =
      File::Spec->splitpath( File::Spec->canonpath($name), $forceDir );
      
    my @dirs = map { $_ =~ s{/}{_}g; $_ } 
               File::Spec->splitdir($directories);

    if ( @dirs > 0 ) { pop (@dirs) if $dirs[-1] eq '' }   # remove empty component
    push @dirs, defined($file) ? $file : '' ;

    my $normalised_path = join '/', @dirs;

    # Leading directory separators should not be stored in zip archives.
    # Example:
    #   C:\a\b\c\      a/b/c
    #   C:\a\b\c.txt   a/b/c.txt
    #   /a/b/c/        a/b/c
    #   /a/b/c.txt     a/b/c.txt
    $normalised_path =~ s{^/}{};  # remove leading separator

    return $normalised_path;
}


sub mkHeader
{
    my $self  = shift;
    my $param = shift ;
    
    *$self->{ZipData}{LocalHdrOffset} = U64::clone(*$self->{ZipData}{Offset});
        
    my $comment = '';
    $comment = $param->valueOrDefault('comment') ;

    my $filename = '';
    $filename = $param->valueOrDefault('name') ;

    $filename = canonicalName($filename)
        if length $filename && $param->getValue('canonicalname') ;

    if (defined *$self->{ZipData}{FilterName} ) {
        local *_ = \$filename ;
        &{ *$self->{ZipData}{FilterName} }() ;
    }

   if ( $param->getValue('efs') && $] >= 5.008004) {
        if (length $filename) {
            utf8::downgrade($filename, 1)
                or Carp::croak "Wide character in zip filename";
        }

        if (length $comment) {
            utf8::downgrade($comment, 1)
                or Carp::croak "Wide character in zip comment";
        }
   }   

    my $hdr = '';

    my $time = _unixToDosTime($param->getValue('time'));

    my $extra = '';
    my $ctlExtra = '';
    my $empty = 0;
    my $osCode = $param->getValue('os_code') ;
    my $extFileAttr = 0 ;
    
    # This code assumes Unix.
    # TODO - revisit this
    $extFileAttr = 0100644 << 16 
        if $osCode == ZIP_OS_CODE_UNIX ;

    if (*$self->{ZipData}{Zip64}) {
        $empty = IO::Compress::Base::Common::MAX32;

        my $x = '';
        $x .= pack "V V", 0, 0 ; # uncompressedLength   
        $x .= pack "V V", 0, 0 ; # compressedLength   
        
        # Zip64 needs to be first in extra field to workaround a Windows Explorer Bug
        # See http://www.info-zip.org/phpBB3/viewtopic.php?f=3&t=440 for details
        $extra .= IO::Compress::Zlib::Extra::mkSubField(ZIP_EXTRA_ID_ZIP64, $x);
    }

    if (! $param->getValue('minimal')) {
        if ($param->parsed('mtime'))
        {
            $extra .= mkExtendedTime($param->getValue('mtime'), 
                                    $param->getValue('atime'), 
                                    $param->getValue('ctime'));

            $ctlExtra .= mkExtendedTime($param->getValue('mtime'));
        }

        if ( $osCode == ZIP_OS_CODE_UNIX )
        {
            if ( $param->getValue('want_exunixn') )
            {
                    my $ux3 = mkUnixNExtra( @{ $param->getValue('want_exunixn') }); 
                    $extra    .= $ux3;
                    $ctlExtra .= $ux3;
            }

            if ( $param->getValue('exunix2') )
            {
                    $extra    .= mkUnix2Extra( @{ $param->getValue('exunix2') }); 
                    $ctlExtra .= mkUnix2Extra();
            }
        }

        $extFileAttr = $param->getValue('extattr') 
            if defined $param->getValue('extattr') ;

        $extra .= $param->getValue('extrafieldlocal') 
            if defined $param->getValue('extrafieldlocal');

        $ctlExtra .= $param->getValue('extrafieldcentral') 
            if defined $param->getValue('extrafieldcentral');
    }

    my $method = *$self->{ZipData}{Method} ;
    my $gpFlag = 0 ;    
    $gpFlag |= ZIP_GP_FLAG_STREAMING_MASK
        if *$self->{ZipData}{Stream} ;

    $gpFlag |= ZIP_GP_FLAG_LZMA_EOS_PRESENT
        if $method == ZIP_CM_LZMA ;

    $gpFlag |= ZIP_GP_FLAG_LANGUAGE_ENCODING
        if  $param->getValue('efs') && (length($filename) || length($comment));

    my $version = $ZIP_CM_MIN_VERSIONS{$method};
    $version = ZIP64_MIN_VERSION
        if ZIP64_MIN_VERSION > $version && *$self->{ZipData}{Zip64};

    my $madeBy = ($param->getValue('os_code') << 8) + $version;
    my $extract = $version;

    *$self->{ZipData}{Version} = $version;
    *$self->{ZipData}{MadeBy} = $madeBy;

    my $ifa = 0;
    $ifa |= ZIP_IFA_TEXT_MASK
        if $param->getValue('textflag');

    $hdr .= pack "V", ZIP_LOCAL_HDR_SIG ; # signature
    $hdr .= pack 'v', $extract   ; # extract Version & OS
    $hdr .= pack 'v', $gpFlag    ; # general purpose flag (set streaming mode)
    $hdr .= pack 'v', $method    ; # compression method (deflate)
    $hdr .= pack 'V', $time      ; # last mod date/time
    $hdr .= pack 'V', 0          ; # crc32               - 0 when streaming
    $hdr .= pack 'V', $empty     ; # compressed length   - 0 when streaming
    $hdr .= pack 'V', $empty     ; # uncompressed length - 0 when streaming
    $hdr .= pack 'v', length $filename ; # filename length
    $hdr .= pack 'v', length $extra ; # extra length
    
    $hdr .= $filename ;

    # Remember the offset for the compressed & uncompressed lengths in the
    # local header.
    if (*$self->{ZipData}{Zip64}) {
        *$self->{ZipData}{SizesOffset} = *$self->{ZipData}{Offset}->get64bit()
            + length($hdr) + 4 ;
    }
    else {
        *$self->{ZipData}{SizesOffset} = *$self->{ZipData}{Offset}->get64bit()
                                            + 18;
    }

    $hdr .= $extra ;


    my $ctl = '';

    $ctl .= pack "V", ZIP_CENTRAL_HDR_SIG ; # signature
    $ctl .= pack 'v', $madeBy    ; # version made by
    $ctl .= pack 'v', $extract   ; # extract Version
    $ctl .= pack 'v', $gpFlag    ; # general purpose flag (streaming mode)
    $ctl .= pack 'v', $method    ; # compression method (deflate)
    $ctl .= pack 'V', $time      ; # last mod date/time
    $ctl .= pack 'V', 0          ; # crc32
    $ctl .= pack 'V', $empty     ; # compressed length
    $ctl .= pack 'V', $empty     ; # uncompressed length
    $ctl .= pack 'v', length $filename ; # filename length

    *$self->{ZipData}{ExtraOffset} = length $ctl;
    *$self->{ZipData}{ExtraSize} = length $ctlExtra ;

    $ctl .= pack 'v', length $ctlExtra ; # extra length
    $ctl .= pack 'v', length $comment ;  # file comment length
    $ctl .= pack 'v', 0          ; # disk number start 
    $ctl .= pack 'v', $ifa       ; # internal file attributes
    $ctl .= pack 'V', $extFileAttr   ; # external file attributes

    # offset to local hdr
    if (*$self->{ZipData}{LocalHdrOffset}->is64bit() ) { 
        $ctl .= pack 'V', IO::Compress::Base::Common::MAX32 ;
    }
    else {
        $ctl .= *$self->{ZipData}{LocalHdrOffset}->getPacked_V32() ; 
    }
    
    $ctl .= $filename ;

    *$self->{ZipData}{Offset}->add32(length $hdr) ;

    *$self->{ZipData}{CentralHeader} = [ $ctl, $ctlExtra, $comment];

    return $hdr;
}

sub mkTrailer
{
    my $self = shift ;

    my $crc32 ;
    if (*$self->{ZipData}{Method} == ZIP_CM_DEFLATE) {
        $crc32 = pack "V", *$self->{Compress}->crc32();
    }
    else {
        $crc32 = pack "V", *$self->{ZipData}{CRC32};
    }

    my ($ctl, $ctlExtra, $comment) = @{ *$self->{ZipData}{CentralHeader} };   

    my $sizes ;
    if (! *$self->{ZipData}{Zip64}) {
        $sizes .= *$self->{CompSize}->getPacked_V32() ;   # Compressed size
        $sizes .= *$self->{UnCompSize}->getPacked_V32() ; # Uncompressed size
    }
    else {
        $sizes .= *$self->{CompSize}->getPacked_V64() ;   # Compressed size
        $sizes .= *$self->{UnCompSize}->getPacked_V64() ; # Uncompressed size
    }

    my $data = $crc32 . $sizes ;

    my $xtrasize  = *$self->{UnCompSize}->getPacked_V64() ; # Uncompressed size
       $xtrasize .= *$self->{CompSize}->getPacked_V64() ;   # Compressed size

    my $hdr = '';

    if (*$self->{ZipData}{Stream}) {
        $hdr  = pack "V", ZIP_DATA_HDR_SIG ;                       # signature
        $hdr .= $data ;
    }
    else {
        $self->writeAt(*$self->{ZipData}{LocalHdrOffset}->get64bit() + 14,  $crc32)
            or return undef;
        $self->writeAt(*$self->{ZipData}{SizesOffset}, 
                *$self->{ZipData}{Zip64} ? $xtrasize : $sizes)
            or return undef;
    }

    # Central Header Record/Zip64 extended field

    substr($ctl, 16, length $crc32) = $crc32 ;

    my $zip64Payload = '';

    # uncompressed length - only set zip64 if needed
    if (*$self->{UnCompSize}->isAlmost64bit()) { #  || *$self->{ZipData}{Zip64}) {
        $zip64Payload .= *$self->{UnCompSize}->getPacked_V64() ; 
    } else {
        substr($ctl, 24, 4) = *$self->{UnCompSize}->getPacked_V32() ;
    }

    # compressed length - only set zip64 if needed
    if (*$self->{CompSize}->isAlmost64bit()) { # || *$self->{ZipData}{Zip64}) {
        $zip64Payload .= *$self->{CompSize}->getPacked_V64() ; 
    } else {
        substr($ctl, 20, 4) = *$self->{CompSize}->getPacked_V32() ;
    }

    # Local Header offset
    $zip64Payload .= *$self->{ZipData}{LocalHdrOffset}->getPacked_V64()
        if *$self->{ZipData}{LocalHdrOffset}->is64bit() ; 

    # disk no - always zero, so don't need to include it.
    #$zip64Payload .= pack "V", 0    ; 

    my $zip64Xtra = '';
    
    if (length $zip64Payload) {
        $zip64Xtra = IO::Compress::Zlib::Extra::mkSubField(ZIP_EXTRA_ID_ZIP64, $zip64Payload);
        
        substr($ctl, *$self->{ZipData}{ExtraOffset}, 2) = 
             pack 'v', *$self->{ZipData}{ExtraSize} + length $zip64Xtra;

        *$self->{ZipData}{AnyZip64} = 1;
    }

    # Zip64 needs to be first in extra field to workaround a Windows Explorer Bug
    # See http://www.info-zip.org/phpBB3/viewtopic.php?f=3&t=440 for details
    $ctl .= $zip64Xtra . $ctlExtra . $comment;
    
    *$self->{ZipData}{Offset}->add32(length($hdr));
    *$self->{ZipData}{Offset}->add( *$self->{CompSize} );
    push @{ *$self->{ZipData}{CentralDir} }, $ctl ;

    return $hdr;
}

sub mkFinalTrailer
{
    my $self = shift ;
        
    my $comment = '';
    $comment = *$self->{ZipData}{ZipComment} ;

    my $cd_offset = *$self->{ZipData}{Offset}->get32bit() ; # offset to start central dir

    my $entries = @{ *$self->{ZipData}{CentralDir} };
    
    *$self->{ZipData}{AnyZip64} = 1 
        if *$self->{ZipData}{Offset}->is64bit || $entries >= 0xFFFF ;      
           
    my $cd = join '', @{ *$self->{ZipData}{CentralDir} };
    my $cd_len = length $cd ;

    my $z64e = '';

    if ( *$self->{ZipData}{AnyZip64} ) {

        my $v  = *$self->{ZipData}{Version} ;
        my $mb = *$self->{ZipData}{MadeBy} ;
        $z64e .= pack 'v', $mb            ; # Version made by
        $z64e .= pack 'v', $v             ; # Version to extract
        $z64e .= pack 'V', 0              ; # number of disk
        $z64e .= pack 'V', 0              ; # number of disk with central dir
        $z64e .= U64::pack_V64 $entries   ; # entries in central dir on this disk
        $z64e .= U64::pack_V64 $entries   ; # entries in central dir
        $z64e .= U64::pack_V64 $cd_len    ; # size of central dir
        $z64e .= *$self->{ZipData}{Offset}->getPacked_V64() ; # offset to start central dir

        $z64e  = pack("V", ZIP64_END_CENTRAL_REC_HDR_SIG) # signature
              .  U64::pack_V64(length $z64e)
              .  $z64e ;

        *$self->{ZipData}{Offset}->add32(length $cd) ; 

        $z64e .= pack "V", ZIP64_END_CENTRAL_LOC_HDR_SIG; # signature
        $z64e .= pack 'V', 0              ; # number of disk with central dir
        $z64e .= *$self->{ZipData}{Offset}->getPacked_V64() ; # offset to end zip64 central dir
        $z64e .= pack 'V', 1              ; # Total number of disks 

        $cd_offset = IO::Compress::Base::Common::MAX32 ;
        $cd_len = IO::Compress::Base::Common::MAX32 if IO::Compress::Base::Common::isGeMax32 $cd_len ;
        $entries = 0xFFFF if $entries >= 0xFFFF ;
    }

    my $ecd = '';
    $ecd .= pack "V", ZIP_END_CENTRAL_HDR_SIG ; # signature
    $ecd .= pack 'v', 0          ; # number of disk
    $ecd .= pack 'v', 0          ; # number of disk with central dir
    $ecd .= pack 'v', $entries   ; # entries in central dir on this disk
    $ecd .= pack 'v', $entries   ; # entries in central dir
    $ecd .= pack 'V', $cd_len    ; # size of central dir
    $ecd .= pack 'V', $cd_offset ; # offset to start central dir
    $ecd .= pack 'v', length $comment ; # zipfile comment length
    $ecd .= $comment;

    return $cd . $z64e . $ecd ;
}

sub ckParams
{
    my $self = shift ;
    my $got = shift;
    
    $got->setValue('crc32' => 1);

    if (! $got->parsed('time') ) {
        # Modification time defaults to now.
        $got->setValue('time' => time) ;
    }

    if ($got->parsed('extime') ) {
        my $timeRef = $got->getValue('extime');
        if ( defined $timeRef) {
            return $self->saveErrorString(undef, "exTime not a 3-element array ref")   
                if ref $timeRef ne 'ARRAY' || @$timeRef != 3;
        }

        $got->setValue("mtime", $timeRef->[1]);
        $got->setValue("atime", $timeRef->[0]);
        $got->setValue("ctime", $timeRef->[2]);
    }
    
    # Unix2/3 Extended Attribute
    for my $name (qw(exunix2 exunixn))
    {
        if ($got->parsed($name) ) {
            my $idRef = $got->getValue($name);
            if ( defined $idRef) {
                return $self->saveErrorString(undef, "$name not a 2-element array ref")   
                    if ref $idRef ne 'ARRAY' || @$idRef != 2;
            }

            $got->setValue("uid", $idRef->[0]);
            $got->setValue("gid", $idRef->[1]);
            $got->setValue("want_$name", $idRef);
        }
    }

    *$self->{ZipData}{AnyZip64} = 1
        if $got->getValue('zip64');
    *$self->{ZipData}{Zip64} = $got->getValue('zip64');
    *$self->{ZipData}{Stream} = $got->getValue('stream');

    my $method = $got->getValue('method');
    return $self->saveErrorString(undef, "Unknown Method '$method'")   
        if ! defined $ZIP_CM_MIN_VERSIONS{$method};

    return $self->saveErrorString(undef, "Bzip2 not available")
        if $method == ZIP_CM_BZIP2 and 
           ! defined $IO::Compress::Adapter::Bzip2::VERSION;

    return $self->saveErrorString(undef, "Lzma not available")
        if $method == ZIP_CM_LZMA 
        and ! defined $IO::Compress::Adapter::Lzma::VERSION;

    *$self->{ZipData}{Method} = $method;

    *$self->{ZipData}{ZipComment} = $got->getValue('zipcomment') ;

    for my $name (qw( extrafieldlocal extrafieldcentral ))
    {
        my $data = $got->getValue($name) ;
        if (defined $data) {
            my $bad = IO::Compress::Zlib::Extra::parseExtraField($data, 1, 0) ;
            return $self->saveErrorString(undef, "Error with $name Parameter: $bad")
                if $bad ;

            $got->setValue($name, $data) ;
        }
    }

    return undef
        if defined $IO::Compress::Bzip2::VERSION
            and ! IO::Compress::Bzip2::ckParams($self, $got);

    if ($got->parsed('sparse') ) {
        *$self->{ZipData}{Sparse} = $got->getValue('sparse') ;
        *$self->{ZipData}{Method} = ZIP_CM_STORE;
    }

    if ($got->parsed('filtername')) {
        my $v = $got->getValue('filtername') ;
        *$self->{ZipData}{FilterName} = $v
            if ref $v eq 'CODE' ;
    }

    return 1 ;
}

sub outputPayload
{
    my $self = shift ;
    return 1 if *$self->{ZipData}{Sparse} ;
    return $self->output(@_);
}


#sub newHeader
#{
#    my $self = shift ;
#
#    return $self->mkHeader(*$self->{Got});
#}


our %PARAMS = (            
            'stream'    => [IO::Compress::Base::Common::Parse_boolean,   1],
           #'store'     => [IO::Compress::Base::Common::Parse_boolean,   0],
            'method'    => [IO::Compress::Base::Common::Parse_unsigned,  ZIP_CM_DEFLATE],
            
#            # Zip header fields
            'minimal'   => [IO::Compress::Base::Common::Parse_boolean,   0],
            'zip64'     => [IO::Compress::Base::Common::Parse_boolean,   0],
            'comment'   => [IO::Compress::Base::Common::Parse_any,       ''],
            'zipcomment'=> [IO::Compress::Base::Common::Parse_any,       ''],
            'name'      => [IO::Compress::Base::Common::Parse_any,       ''],
            'filtername'=> [IO::Compress::Base::Common::Parse_code,      undef],
            'canonicalname'=> [IO::Compress::Base::Common::Parse_boolean,   0],
            'efs'       => [IO::Compress::Base::Common::Parse_boolean,   0],
            'time'      => [IO::Compress::Base::Common::Parse_any,       undef],
            'extime'    => [IO::Compress::Base::Common::Parse_any,       undef],
            'exunix2'   => [IO::Compress::Base::Common::Parse_any,       undef], 
            'exunixn'   => [IO::Compress::Base::Common::Parse_any,       undef], 
            'extattr'   => [IO::Compress::Base::Common::Parse_any, 
                    $Compress::Raw::Zlib::gzip_os_code == 3 
                        ? 0100644 << 16 
                        : 0],
            'os_code'   => [IO::Compress::Base::Common::Parse_unsigned,  $Compress::Raw::Zlib::gzip_os_code],
            
            'textflag'  => [IO::Compress::Base::Common::Parse_boolean,   0],
            'extrafieldlocal'  => [IO::Compress::Base::Common::Parse_any,    undef],
            'extrafieldcentral'=> [IO::Compress::Base::Common::Parse_any,    undef],

            # Lzma
            'preset'   => [IO::Compress::Base::Common::Parse_unsigned, 6],
            'extreme'  => [IO::Compress::Base::Common::Parse_boolean,  0],

            # For internal use only         
            'sparse'    => [IO::Compress::Base::Common::Parse_unsigned,  0],

            IO::Compress::RawDeflate::getZlibParams(),
            defined $IO::Compress::Bzip2::VERSION
                ? IO::Compress::Bzip2::getExtraParams()
                : ()
                
  
                );

sub getExtraParams
{
    return %PARAMS ;
}

sub getInverseClass
{
    return ('IO::Uncompress::Unzip',
                \$IO::Uncompress::Unzip::UnzipError);
}

sub getFileInfo
{
    my $self = shift ;
    my $params = shift;
    my $filename = shift ;

    if (IO::Compress::Base::Common::isaScalar($filename))
    {
        $params->setValue(zip64 => 1)
            if IO::Compress::Base::Common::isGeMax32 length (${ $filename }) ;

        return ;
    }

    my ($mode, $uid, $gid, $size, $atime, $mtime, $ctime) ;
    if ( $params->parsed('storelinks') )
    {
        ($mode, $uid, $gid, $size, $atime, $mtime, $ctime) 
                = (lstat($filename))[2, 4,5,7, 8,9,10] ;
    }
    else
    {
        ($mode, $uid, $gid, $size, $atime, $mtime, $ctime) 
                = (stat($filename))[2, 4,5,7, 8,9,10] ;
    }

    $params->setValue(textflag => -T $filename )
        if ! $params->parsed('textflag');

    $params->setValue(zip64 => 1)
        if IO::Compress::Base::Common::isGeMax32 $size ;

    $params->setValue('name' => $filename)
        if ! $params->parsed('name') ;

    $params->setValue('time' => $mtime) 
        if ! $params->parsed('time') ;
    
    if ( ! $params->parsed('extime'))
    {
        $params->setValue('mtime' => $mtime) ;
        $params->setValue('atime' => $atime) ;
        $params->setValue('ctime' => undef) ; # No Creation time
        # TODO - see if can fillout creation time on non-Unix
    }

    # NOTE - Unix specific code alert
    if (! $params->parsed('extattr'))
    {
        use Fcntl qw(:mode) ;
        my $attr = $mode << 16;
        $attr |= ZIP_A_RONLY if ($mode & S_IWRITE) == 0 ;
        $attr |= ZIP_A_DIR   if ($mode & S_IFMT  ) == S_IFDIR ;
        
        $params->setValue('extattr' => $attr);
    }

    $params->setValue('want_exunixn', [$uid, $gid]);
    $params->setValue('uid' => $uid) ;
    $params->setValue('gid' => $gid) ;
    
}

sub mkExtendedTime
{
    # order expected is m, a, c

    my $times = '';
    my $bit = 1 ;
    my $flags = 0;

    for my $time (@_)
    {
        if (defined $time)
        {
            $flags |= $bit;
            $times .= pack("V", $time);
        }

        $bit <<= 1 ;
    }

    return IO::Compress::Zlib::Extra::mkSubField(ZIP_EXTRA_ID_EXT_TIMESTAMP,
                                                 pack("C", $flags) .  $times);
}

sub mkUnix2Extra
{
    my $ids = '';
    for my $id (@_)
    {
        $ids .= pack("v", $id);
    }

    return IO::Compress::Zlib::Extra::mkSubField(ZIP_EXTRA_ID_INFO_ZIP_UNIX2, 
                                                 $ids);
}

sub mkUnixNExtra
{
    my $uid = shift;
    my $gid = shift;

    # Assumes UID/GID are 32-bit
    my $ids ;
    $ids .= pack "C", 1; # version
    $ids .= pack "C", $Config{uidsize};
    $ids .= pack "V", $uid;
    $ids .= pack "C", $Config{gidsize};
    $ids .= pack "V", $gid;

    return IO::Compress::Zlib::Extra::mkSubField(ZIP_EXTRA_ID_INFO_ZIP_UNIXN, 
                                                 $ids);
}


# from Archive::Zip
sub _unixToDosTime    # Archive::Zip::Member
{
	my $time_t = shift;
    
    # TODO - add something to cope with unix time < 1980 
	my ( $sec, $min, $hour, $mday, $mon, $year ) = localtime($time_t);
	my $dt = 0;
	$dt += ( $sec >> 1 );
	$dt += ( $min << 5 );
	$dt += ( $hour << 11 );
	$dt += ( $mday << 16 );
	$dt += ( ( $mon + 1 ) << 21 );
	$dt += ( ( $year - 80 ) << 25 );
	return $dt;
}

1;

__END__

=head1 NAME

IO::Compress::Zip - Write zip files/buffers

=head1 SYNOPSIS

    use IO::Compress::Zip qw(zip $ZipError) ;

    my $status = zip $input => $output [,OPTS]
        or die "zip failed: $ZipError\n";

    my $z = new IO::Compress::Zip $output [,OPTS]
        or die "zip failed: $ZipError\n";

    $z->print($string);
    $z->printf($format, $string);
    $z->write($string);
    $z->syswrite($string [, $length, $offset]);
    $z->flush();
    $z->tell();
    $z->eof();
    $z->seek($position, $whence);
    $z->binmode();
    $z->fileno();
    $z->opened();
    $z->autoflush();
    $z->input_line_number();
    $z->newStream( [OPTS] );

    $z->deflateParams();

    $z->close() ;

    $ZipError ;

    # IO::File mode

    print $z $string;
    printf $z $format, $string;
    tell $z
    eof $z
    seek $z, $position, $whence
    binmode $z
    fileno $z
    close $z ;

=head1 DESCRIPTION

This module provides a Perl interface that allows writing zip
compressed data to files or buffer.

The primary purpose of this module is to provide streaming write access to
zip files and buffers. It is not a general-purpose file archiver. If that
is what you want, check out C<Archive::Zip> or C<Archive::Zip::SimpleZip>.

At present the following compression methods are supported by IO::Compress::Zip,
namely Store (no compression at all), Deflate, Bzip2 and LZMA.

B<Note>

=over 5

=item * To use Bzip2 compression, the module C<IO::Compress::Bzip2> must be installed.

=item * To use LZMA compression, the module C<IO::Compress::Lzma> must be installed.

=back

For reading zip files/buffers, see the companion module
L<IO::Uncompress::Unzip|IO::Uncompress::Unzip>.

=head1 Functional Interface

A top-level function, C<zip>, is provided to carry out
"one-shot" compression between buffers and/or files. For finer
control over the compression process, see the L</"OO Interface">
section.

    use IO::Compress::Zip qw(zip $ZipError) ;

    zip $input_filename_or_reference => $output_filename_or_reference [,OPTS]
        or die "zip failed: $ZipError\n";

The functional interface needs Perl5.005 or better.

=head2 zip $input_filename_or_reference => $output_filename_or_reference [, OPTS]

C<zip> expects at least two parameters,
C<$input_filename_or_reference> and C<$output_filename_or_reference>
and zero or more optional parameters (see L</Optional Parameters>)

=head3 The C<$input_filename_or_reference> parameter

The parameter, C<$input_filename_or_reference>, is used to define the
source of the uncompressed data.

It can take one of the following forms:

=over 5

=item A filename

If the C<$input_filename_or_reference> parameter is a simple scalar, it is
assumed to be a filename. This file will be opened for reading and the
input data will be read from it.

=item A filehandle

If the C<$input_filename_or_reference> parameter is a filehandle, the input
data will be read from it.  The string '-' can be used as an alias for
standard input.

=item A scalar reference

If C<$input_filename_or_reference> is a scalar reference, the input data
will be read from C<$$input_filename_or_reference>.

=item An array reference

If C<$input_filename_or_reference> is an array reference, each element in
the array must be a filename.

The input data will be read from each file in turn.

The complete array will be walked to ensure that it only
contains valid filenames before any data is compressed.

=item An Input FileGlob string

If C<$input_filename_or_reference> is a string that is delimited by the
characters "<" and ">" C<zip> will assume that it is an
I<input fileglob string>. The input is the list of files that match the
fileglob.

See L<File::GlobMapper|File::GlobMapper> for more details.

=back

If the C<$input_filename_or_reference> parameter is any other type,
C<undef> will be returned.

In addition, if C<$input_filename_or_reference> is a simple filename,
the default values for
the C<Name>, C<Time>, C<TextFlag>, C<ExtAttr>, C<exUnixN> and C<exTime> options will be sourced from that file.

If you do not want to use these defaults they can be overridden by
explicitly setting the C<Name>, C<Time>, C<TextFlag>, C<ExtAttr>, C<exUnixN> and C<exTime> options or by setting the
C<Minimal> parameter.

=head3 The C<$output_filename_or_reference> parameter

The parameter C<$output_filename_or_reference> is used to control the
destination of the compressed data. This parameter can take one of
these forms.

=over 5

=item A filename

If the C<$output_filename_or_reference> parameter is a simple scalar, it is
assumed to be a filename.  This file will be opened for writing and the
compressed data will be written to it.

=item A filehandle

If the C<$output_filename_or_reference> parameter is a filehandle, the
compressed data will be written to it.  The string '-' can be used as
an alias for standard output.

=item A scalar reference

If C<$output_filename_or_reference> is a scalar reference, the
compressed data will be stored in C<$$output_filename_or_reference>.

=item An Array Reference

If C<$output_filename_or_reference> is an array reference,
the compressed data will be pushed onto the array.

=item An Output FileGlob

If C<$output_filename_or_reference> is a string that is delimited by the
characters "<" and ">" C<zip> will assume that it is an
I<output fileglob string>. The output is the list of files that match the
fileglob.

When C<$output_filename_or_reference> is an fileglob string,
C<$input_filename_or_reference> must also be a fileglob string. Anything
else is an error.

See L<File::GlobMapper|File::GlobMapper> for more details.

=back

If the C<$output_filename_or_reference> parameter is any other type,
C<undef> will be returned.

=head2 Notes

When C<$input_filename_or_reference> maps to multiple files/buffers and
C<$output_filename_or_reference> is a single
file/buffer the input files/buffers will each be stored
in C<$output_filename_or_reference> as a distinct entry.

=head2 Optional Parameters

The optional parameters for the one-shot function C<zip>
are (for the most part) identical to those used with the OO interface defined in the
L</"Constructor Options"> section. The exceptions are listed below

=over 5

=item C<< AutoClose => 0|1 >>

This option applies to any input or output data streams to
C<zip> that are filehandles.

If C<AutoClose> is specified, and the value is true, it will result in all
input and/or output filehandles being closed once C<zip> has
completed.

This parameter defaults to 0.

=item C<< BinModeIn => 0|1 >>

This option is now a no-op. All files will be read in binmode.

=item C<< Append => 0|1 >>

The behaviour of this option is dependent on the type of output data
stream.

=over 5

=item * A Buffer

If C<Append> is enabled, all compressed data will be append to the end of
the output buffer. Otherwise the output buffer will be cleared before any
compressed data is written to it.

=item * A Filename

If C<Append> is enabled, the file will be opened in append mode. Otherwise
the contents of the file, if any, will be truncated before any compressed
data is written to it.

=item * A Filehandle

If C<Append> is enabled, the filehandle will be positioned to the end of
the file via a call to C<seek> before any compressed data is
written to it.  Otherwise the file pointer will not be moved.

=back

When C<Append> is specified, and set to true, it will I<append> all compressed
data to the output data stream.

So when the output is a filehandle it will carry out a seek to the eof
before writing any compressed data. If the output is a filename, it will be opened for
appending. If the output is a buffer, all compressed data will be
appended to the existing buffer.

Conversely when C<Append> is not specified, or it is present and is set to
false, it will operate as follows.

When the output is a filename, it will truncate the contents of the file
before writing any compressed data. If the output is a filehandle
its position will not be changed. If the output is a buffer, it will be
wiped before any compressed data is output.

Defaults to 0.

=back

=head2 Examples

Here are a few example that show the capabilities of the module.

=head3 Streaming

This very simple command line example demonstrates the streaming capabilities of the module.
The code reads data from STDIN, compresses it, and writes the compressed data to STDOUT.

    $ echo hello world | perl -MIO::Compress::Zip=zip -e 'zip \*STDIN => \*STDOUT' >output.zip

The special filename "-" can be used as a standin for both C<\*STDIN> and C<\*STDOUT>,
so the above can be rewritten as

    $ echo hello world | perl -MIO::Compress::Zip=zip -e 'zip "-" => "-"' >output.zip

One problem with creating a zip archive directly from STDIN can be demonstrated by looking at
the contents of the zip file, output.zip, that we have just created.

    $ unzip -l output.zip
    Archive:  output.zip
    Length      Date    Time    Name
    ---------  ---------- -----   ----
        12  2019-08-16 22:21
    ---------                     -------
        12                     1 file

The archive member (filename) used is the empty string.

If that doesn't suit your needs, you can explicitly set the filename used
in the zip archive by specifying the L<Name|"File Naming Options"> option, like so

    echo hello world | perl -MIO::Compress::Zip=zip -e 'zip "-" => "-", Name => "hello.txt"' >output.zip

Now the contents of the zip file looks like this

    $ unzip -l output.zip
    Archive:  output.zip
    Length      Date    Time    Name
    ---------  ---------- -----   ----
        12  2019-08-16 22:22   hello.txt
    ---------                     -------
        12                     1 file

=head3 Compressing a file from the filesystem

To read the contents of the file C<file1.txt> and write the compressed
data to the file C<file1.txt.zip>.

    use strict ;
    use warnings ;
    use IO::Compress::Zip qw(zip $ZipError) ;

    my $input = "file1.txt";
    zip $input => "$input.zip"
        or die "zip failed: $ZipError\n";

=head3 Reading from a Filehandle and writing to an in-memory buffer

To read from an existing Perl filehandle, C<$input>, and write the
compressed data to a buffer, C<$buffer>.

    use strict ;
    use warnings ;
    use IO::Compress::Zip qw(zip $ZipError) ;
    use IO::File ;

    my $input = new IO::File "<file1.txt"
        or die "Cannot open 'file1.txt': $!\n" ;
    my $buffer ;
    zip $input => \$buffer
        or die "zip failed: $ZipError\n";

=head3 Compressing multiple files

To create a zip file, C<output.zip>, that contains the compressed contents
of the files C<alpha.txt> and C<beta.txt>

    use strict ;
    use warnings ;
    use IO::Compress::Zip qw(zip $ZipError) ;

    zip [ 'alpha.txt', 'beta.txt' ] => 'output.zip'
        or die "zip failed: $ZipError\n";

Alternatively, rather than having to explicitly name each of the files that
you want to compress, you could use a fileglob to select all the C<txt>
files in the current directory, as follows

    use strict ;
    use warnings ;
    use IO::Compress::Zip qw(zip $ZipError) ;

    my @files = <*.txt>;
    zip \@files => 'output.zip'
        or die "zip failed: $ZipError\n";

or more succinctly

    zip [ <*.txt> ] => 'output.zip'
        or die "zip failed: $ZipError\n";

=head1 OO Interface

=head2 Constructor

The format of the constructor for C<IO::Compress::Zip> is shown below

    my $z = new IO::Compress::Zip $output [,OPTS]
        or die "IO::Compress::Zip failed: $ZipError\n";

It returns an C<IO::Compress::Zip> object on success and undef on failure.
The variable C<$ZipError> will contain an error message on failure.

If you are running Perl 5.005 or better the object, C<$z>, returned from
IO::Compress::Zip can be used exactly like an L<IO::File|IO::File> filehandle.
This means that all normal output file operations can be carried out
with C<$z>.
For example, to write to a compressed file/buffer you can use either of
these forms

    $z->print("hello world\n");
    print $z "hello world\n";

The mandatory parameter C<$output> is used to control the destination
of the compressed data. This parameter can take one of these forms.

=over 5

=item A filename

If the C<$output> parameter is a simple scalar, it is assumed to be a
filename. This file will be opened for writing and the compressed data
will be written to it.

=item A filehandle

If the C<$output> parameter is a filehandle, the compressed data will be
written to it.
The string '-' can be used as an alias for standard output.

=item A scalar reference

If C<$output> is a scalar reference, the compressed data will be stored
in C<$$output>.

=back

If the C<$output> parameter is any other type, C<IO::Compress::Zip>::new will
return undef.

=head2 Constructor Options

C<OPTS> is any combination of zero or more the following options:

=over 5

=item C<< AutoClose => 0|1 >>

This option is only valid when the C<$output> parameter is a filehandle. If
specified, and the value is true, it will result in the C<$output> being
closed once either the C<close> method is called or the C<IO::Compress::Zip>
object is destroyed.

This parameter defaults to 0.

=item C<< Append => 0|1 >>

Opens C<$output> in append mode.

The behaviour of this option is dependent on the type of C<$output>.

=over 5

=item * A Buffer

If C<$output> is a buffer and C<Append> is enabled, all compressed data
will be append to the end of C<$output>. Otherwise C<$output> will be
cleared before any data is written to it.

=item * A Filename

If C<$output> is a filename and C<Append> is enabled, the file will be
opened in append mode. Otherwise the contents of the file, if any, will be
truncated before any compressed data is written to it.

=item * A Filehandle

If C<$output> is a filehandle, the file pointer will be positioned to the
end of the file via a call to C<seek> before any compressed data is written
to it.  Otherwise the file pointer will not be moved.

=back

This parameter defaults to 0.

=back

=head3 File Naming Options

A quick bit of zip file terminology -- A zip archive consists of one or more I<archive members>, where each member has an associated 
filename, known as the I<archive member name>.

The options listed in this section control how the I<archive member name> (or filename) is stored the zip archive.

=over 5

=item C<< Name => $string >>

This option is used to explicitly set the I<archive member name> in
the zip archive to C<$string>.
Most of the time you don't need to make use of this option.
By default when adding a filename to the zip archive, the I<archive member name> will match the filename.

You should only need to use this option if you want the I<archive member name>
to be different from the uncompressed filename or when the input is a filehandle or a buffer.

The default behaviour for what I<archive member name> is used when the C<Name> option 
is I<not> specified depends on the form of the C<$input> parameter:

=over 5

=item *

If the C<$input> parameter is a filename, the
value of C<$input> will be used for the I<archive member name> .

=item * 
If the C<$input> parameter is not a filename,
the I<archive member name> will be an empty string.

=back 

Note that both the C<CanonicalName> and C<FilterName> options
can modify the value used for the I<archive member name>.

Also note that you should set the C<Efs> option to true if you are working
with UTF8 filenames.

=item C<< CanonicalName => 0|1 >>

This option controls whether the I<archive member name> is
I<normalized> into Unix format before being written to the zip file.

It is recommended that you enable this option unless you really need
to create a non-standard Zip file.

This is what APPNOTE.TXT has to say on what should be stored in the zip
filename header field.

    The name of the file, with optional relative path.
    The path stored should not contain a drive or
    device letter, or a leading slash.  All slashes
    should be forward slashes '/' as opposed to
    backwards slashes '\' for compatibility with Amiga
    and UNIX file systems etc.

This option defaults to B<false>.

=item C<< FilterName => sub { ... }  >>

This option allow the I<archive member> name to be modified
before it is written to the zip file.

This option takes a parameter that must be a reference to a sub.  On entry
to the sub the C<$_> variable will contain the name to be filtered. If no
filename is available C<$_> will contain an empty string.

The value of C<$_> when the sub returns will be  used as the I<archive member name>.

Note that if C<CanonicalName> is enabled, a
normalized filename will be passed to the sub.

If you use C<FilterName> to modify the filename, it is your responsibility
to keep the filename in Unix format.

Although this option can be used with the OO interface, it is of most use
with the one-shot interface. For example, the code below shows how
C<FilterName> can be used to remove the path component from a series of
filenames before they are stored in C<$zipfile>.

    sub compressTxtFiles
    {
        my $zipfile = shift ;
        my $dir     = shift ;

        zip [ <$dir/*.txt> ] => $zipfile,
            FilterName => sub { s[^$dir/][] } ;
    }

=item C<< Efs => 0|1 >>

This option controls setting of the "Language Encoding Flag" (EFS) in the zip
archive. When set, the filename and comment fields for the zip archive MUST
be valid UTF-8.

If the string used for the filename and/or comment is not valid UTF-8 when this option
is true, the script will die with a "wide character" error.

Note that this option only works with Perl 5.8.4 or better.

This option defaults to B<false>.

=back

=head3 Overall Zip Archive Structure

=over 5

=item C<< Minimal => 1|0 >>

If specified, this option will disable the creation of all extra fields
in the zip local and central headers. So the C<exTime>, C<exUnix2>,
C<exUnixN>, C<ExtraFieldLocal> and C<ExtraFieldCentral> options will
be ignored.

This parameter defaults to 0.

=item C<< Stream => 0|1 >>

This option controls whether the zip file/buffer output is created in
streaming mode.

Note that when outputting to a file with streaming mode disabled (C<Stream>
is 0), the output file must be seekable.

The default is 1.

=item C<< Zip64 => 0|1 >>

Create a Zip64 zip file/buffer. This option is used if you want
to store files larger than 4 Gig or store more than 64K files in a single
zip archive.

C<Zip64> will be automatically set, as needed, if working with the one-shot
interface when the input is either a filename or a scalar reference.

If you intend to manipulate the Zip64 zip files created with this module
using an external zip/unzip, make sure that it supports Zip64.

In particular, if you are using Info-Zip you need to have zip version 3.x
or better to update a Zip64 archive and unzip version 6.x to read a zip64
archive.

The default is 0.

=back 

=head3 Deflate Compression Options

=over 5

=item -Level

Defines the compression level used by zlib. The value should either be
a number between 0 and 9 (0 means no compression and 9 is maximum
compression), or one of the symbolic constants defined below.

   Z_NO_COMPRESSION
   Z_BEST_SPEED
   Z_BEST_COMPRESSION
   Z_DEFAULT_COMPRESSION

The default is Z_DEFAULT_COMPRESSION.

Note, these constants are not imported by C<IO::Compress::Zip> by default.

    use IO::Compress::Zip qw(:strategy);
    use IO::Compress::Zip qw(:constants);
    use IO::Compress::Zip qw(:all);

=item -Strategy

Defines the strategy used to tune the compression. Use one of the symbolic
constants defined below.

   Z_FILTERED
   Z_HUFFMAN_ONLY
   Z_RLE
   Z_FIXED
   Z_DEFAULT_STRATEGY

The default is Z_DEFAULT_STRATEGY.

=back

=head3 Bzip2 Compression Options

=over 5

=item C<< BlockSize100K => number >>

Specify the number of 100K blocks bzip2 uses during compression.

Valid values are from 1 to 9, where 9 is best compression.

This option is only valid if the C<Method> is ZIP_CM_BZIP2. It is ignored
otherwise.

The default is 1.

=item C<< WorkFactor => number >>

Specifies how much effort bzip2 should take before resorting to a slower
fallback compression algorithm.

Valid values range from 0 to 250, where 0 means use the default value 30.

This option is only valid if the C<Method> is ZIP_CM_BZIP2. It is ignored
otherwise.

The default is 0.

=back

=head3 Lzma Compression Options

=over 5

=item C<< Preset => number >>

Used to choose the LZMA compression preset.

Valid values are 0-9 and C<LZMA_PRESET_DEFAULT>.

0 is the fastest compression with the lowest memory usage and the lowest
compression.

9 is the slowest compression with the highest memory usage but with the best
compression.

This option is only valid if the C<Method> is ZIP_CM_LZMA. It is ignored
otherwise.

Defaults to C<LZMA_PRESET_DEFAULT> (6).

=item C<< Extreme => 0|1 >>

Makes LZMA compression a lot slower, but a small compression gain.

This option is only valid if the C<Method> is ZIP_CM_LZMA. It is ignored
otherwise.

Defaults to 0.

=back

=head3 Other Options

=over 5

=item C<< Time => $number >>

Sets the last modified time field in the zip header to $number.

This field defaults to the time the C<IO::Compress::Zip> object was created
if this option is not specified and the C<$input> parameter is not a
filename.

=item C<< ExtAttr => $attr >>

This option controls the "external file attributes" field in the central
header of the zip file. This is a 4 byte field.

If you are running a Unix derivative this value defaults to

    0100644 << 16

This should allow read/write access to any files that are extracted from
the zip file/buffer`.

For all other systems it defaults to 0.

=item C<< exTime => [$atime, $mtime, $ctime] >>

This option expects an array reference with exactly three elements:
C<$atime>, C<mtime> and C<$ctime>. These correspond to the last access
time, last modification time and creation time respectively.

It uses these values to set the extended timestamp field (ID is "UT") in
the local zip header using the three values, $atime, $mtime, $ctime. In
addition it sets the extended timestamp field in the central zip header
using C<$mtime>.

If any of the three values is C<undef> that time value will not be used.
So, for example, to set only the C<$mtime> you would use this

    exTime => [undef, $mtime, undef]

If the C<Minimal> option is set to true, this option will be ignored.

By default no extended time field is created.

=item C<< exUnix2 => [$uid, $gid] >>

This option expects an array reference with exactly two elements: C<$uid>
and C<$gid>. These values correspond to the numeric User ID (UID) and Group ID
(GID) of the owner of the files respectively.

When the C<exUnix2> option is present it will trigger the creation of a
Unix2 extra field (ID is "Ux") in the local zip header. This will be populated
with C<$uid> and C<$gid>. An empty Unix2 extra field will also
be created in the central zip header.

Note - The UID & GID are stored as 16-bit
integers in the "Ux" field. Use C<< exUnixN >> if your UID or GID are
32-bit.

If the C<Minimal> option is set to true, this option will be ignored.

By default no Unix2 extra field is created.

=item C<< exUnixN => [$uid, $gid] >>

This option expects an array reference with exactly two elements: C<$uid>
and C<$gid>. These values correspond to the numeric User ID (UID) and Group ID
(GID) of the owner of the files respectively.

When the C<exUnixN> option is present it will trigger the creation of a
UnixN extra field (ID is "ux") in both the local and central zip headers.
This will be populated with C<$uid> and C<$gid>.
The UID & GID are stored as 32-bit integers.

If the C<Minimal> option is set to true, this option will be ignored.

By default no UnixN extra field is created.

=item C<< Comment => $comment >>

Stores the contents of C<$comment> in the Central File Header of
the zip file.

Set the C<Efs> option to true if you want to store a UTF8 comment.

By default, no comment field is written to the zip file.

=item C<< ZipComment => $comment >>

Stores the contents of C<$comment> in the End of Central Directory record
of the zip file.

By default, no comment field is written to the zip file.

=item C<< Method => $method >>

Controls which compression method is used. At present four compression
methods are supported, namely Store (no compression at all), Deflate,
Bzip2 and Lzma.

The symbols, ZIP_CM_STORE, ZIP_CM_DEFLATE, ZIP_CM_BZIP2 and ZIP_CM_LZMA
are used to select the compression method.

These constants are not imported by C<IO::Compress::Zip> by default.

    use IO::Compress::Zip qw(:zip_method);
    use IO::Compress::Zip qw(:constants);
    use IO::Compress::Zip qw(:all);

Note that to create Bzip2 content, the module C<IO::Compress::Bzip2> must
be installed. A fatal error will be thrown if you attempt to create Bzip2
content when C<IO::Compress::Bzip2> is not available.

Note that to create Lzma content, the module C<IO::Compress::Lzma> must
be installed. A fatal error will be thrown if you attempt to create Lzma
content when C<IO::Compress::Lzma> is not available.

The default method is ZIP_CM_DEFLATE.

=item C<< TextFlag => 0|1 >>

This parameter controls the setting of a bit in the zip central header. It
is used to signal that the data stored in the zip file/buffer is probably
text.

In one-shot mode this flag will be set to true if the Perl C<-T> operator thinks
the file contains text.

The default is 0.

=item C<< ExtraFieldLocal => $data >>

=item C<< ExtraFieldCentral => $data >>

The C<ExtraFieldLocal> option is used to store additional metadata in the
local header for the zip file/buffer. The C<ExtraFieldCentral> does the
same for the matching central header.

An extra field consists of zero or more subfields. Each subfield consists
of a two byte header followed by the subfield data.

The list of subfields can be supplied in any of the following formats

    ExtraFieldLocal => [$id1, $data1,
                        $id2, $data2,
                         ...
                       ]

    ExtraFieldLocal => [ [$id1 => $data1],
                         [$id2 => $data2],
                         ...
                       ]

    ExtraFieldLocal => { $id1 => $data1,
                         $id2 => $data2,
                         ...
                       }

Where C<$id1>, C<$id2> are two byte subfield ID's.

If you use the hash syntax, you have no control over the order in which
the ExtraSubFields are stored, plus you cannot have SubFields with
duplicate ID.

Alternatively the list of subfields can by supplied as a scalar, thus

    ExtraField => $rawdata

In this case C<IO::Compress::Zip> will check that C<$rawdata> consists of
zero or more conformant sub-fields.

The Extended Time field (ID "UT"), set using the C<exTime> option, and the
Unix2 extra field (ID "Ux), set using the C<exUnix2> option, are examples
of extra fields.

If the C<Minimal> option is set to true, this option will be ignored.

The maximum size of an extra field 65535 bytes.

=item C<< Strict => 0|1 >>

This is a placeholder option.

=back

=head2 Examples

TODO

=head1 Methods

=head2 print

Usage is

    $z->print($data)
    print $z $data

Compresses and outputs the contents of the C<$data> parameter. This
has the same behaviour as the C<print> built-in.

Returns true if successful.

=head2 printf

Usage is

    $z->printf($format, $data)
    printf $z $format, $data

Compresses and outputs the contents of the C<$data> parameter.

Returns true if successful.

=head2 syswrite

Usage is

    $z->syswrite $data
    $z->syswrite $data, $length
    $z->syswrite $data, $length, $offset

Compresses and outputs the contents of the C<$data> parameter.

Returns the number of uncompressed bytes written, or C<undef> if
unsuccessful.

=head2 write

Usage is

    $z->write $data
    $z->write $data, $length
    $z->write $data, $length, $offset

Compresses and outputs the contents of the C<$data> parameter.

Returns the number of uncompressed bytes written, or C<undef> if
unsuccessful.

=head2 flush

Usage is

    $z->flush;
    $z->flush($flush_type);

Flushes any pending compressed data to the output file/buffer.

This method takes an optional parameter, C<$flush_type>, that controls
how the flushing will be carried out. By default the C<$flush_type>
used is C<Z_FINISH>. Other valid values for C<$flush_type> are
C<Z_NO_FLUSH>, C<Z_SYNC_FLUSH>, C<Z_FULL_FLUSH> and C<Z_BLOCK>. It is
strongly recommended that you only set the C<flush_type> parameter if
you fully understand the implications of what it does - overuse of C<flush>
can seriously degrade the level of compression achieved. See the C<zlib>
documentation for details.

Returns true on success.

=head2 tell

Usage is

    $z->tell()
    tell $z

Returns the uncompressed file offset.

=head2 eof

Usage is

    $z->eof();
    eof($z);

Returns true if the C<close> method has been called.

=head2 seek

    $z->seek($position, $whence);
    seek($z, $position, $whence);

Provides a sub-set of the C<seek> functionality, with the restriction
that it is only legal to seek forward in the output file/buffer.
It is a fatal error to attempt to seek backward.

Empty parts of the file/buffer will have NULL (0x00) bytes written to them.

The C<$whence> parameter takes one the usual values, namely SEEK_SET,
SEEK_CUR or SEEK_END.

Returns 1 on success, 0 on failure.

=head2 binmode

Usage is

    $z->binmode
    binmode $z ;

This is a noop provided for completeness.

=head2 opened

    $z->opened()

Returns true if the object currently refers to a opened file/buffer.

=head2 autoflush

    my $prev = $z->autoflush()
    my $prev = $z->autoflush(EXPR)

If the C<$z> object is associated with a file or a filehandle, this method
returns the current autoflush setting for the underlying filehandle. If
C<EXPR> is present, and is non-zero, it will enable flushing after every
write/print operation.

If C<$z> is associated with a buffer, this method has no effect and always
returns C<undef>.

B<Note> that the special variable C<$|> B<cannot> be used to set or
retrieve the autoflush setting.

=head2 input_line_number

    $z->input_line_number()
    $z->input_line_number(EXPR)

This method always returns C<undef> when compressing.

=head2 fileno

    $z->fileno()
    fileno($z)

If the C<$z> object is associated with a file or a filehandle, C<fileno>
will return the underlying file descriptor. Once the C<close> method is
called C<fileno> will return C<undef>.

If the C<$z> object is associated with a buffer, this method will return
C<undef>.

=head2 close

    $z->close() ;
    close $z ;

Flushes any pending compressed data and then closes the output file/buffer.

For most versions of Perl this method will be automatically invoked if
the IO::Compress::Zip object is destroyed (either explicitly or by the
variable with the reference to the object going out of scope). The
exceptions are Perl versions 5.005 through 5.00504 and 5.8.0. In
these cases, the C<close> method will be called automatically, but
not until global destruction of all live objects when the program is
terminating.

Therefore, if you want your scripts to be able to run on all versions
of Perl, you should call C<close> explicitly and not rely on automatic
closing.

Returns true on success, otherwise 0.

If the C<AutoClose> option has been enabled when the IO::Compress::Zip
object was created, and the object is associated with a file, the
underlying file will also be closed.

=head2 newStream([OPTS])

Usage is

    $z->newStream( [OPTS] )

Closes the current compressed data stream and starts a new one.

OPTS consists of any of the options that are available when creating
the C<$z> object.

See the L</"Constructor Options"> section for more details.

=head2 deflateParams

Usage is

    $z->deflateParams

TODO

=head1 Importing

A number of symbolic constants are required by some methods in
C<IO::Compress::Zip>. None are imported by default.

=over 5

=item :all

Imports C<zip>, C<$ZipError> and all symbolic
constants that can be used by C<IO::Compress::Zip>. Same as doing this

    use IO::Compress::Zip qw(zip $ZipError :constants) ;

=item :constants

Import all symbolic constants. Same as doing this

    use IO::Compress::Zip qw(:flush :level :strategy :zip_method) ;

=item :flush

These symbolic constants are used by the C<flush> method.

    Z_NO_FLUSH
    Z_PARTIAL_FLUSH
    Z_SYNC_FLUSH
    Z_FULL_FLUSH
    Z_FINISH
    Z_BLOCK

=item :level

These symbolic constants are used by the C<Level> option in the constructor.

    Z_NO_COMPRESSION
    Z_BEST_SPEED
    Z_BEST_COMPRESSION
    Z_DEFAULT_COMPRESSION

=item :strategy

These symbolic constants are used by the C<Strategy> option in the constructor.

    Z_FILTERED
    Z_HUFFMAN_ONLY
    Z_RLE
    Z_FIXED
    Z_DEFAULT_STRATEGY

=item :zip_method

These symbolic constants are used by the C<Method> option in the
constructor.

    ZIP_CM_STORE
    ZIP_CM_DEFLATE
    ZIP_CM_BZIP2

=back

=head1 EXAMPLES

=head2 Apache::GZip Revisited

See L<IO::Compress::FAQ|IO::Compress::FAQ/"Apache::GZip Revisited">

=head2 Working with Net::FTP

See L<IO::Compress::FAQ|IO::Compress::FAQ/"Compressed files and Net::FTP">

=head1 SUPPORT

General feedback/questions/bug reports should be sent to 
L<https://github.com/pmqs/IO-Compress/issues> (preferred) or
L<https://rt.cpan.org/Public/Dist/Display.html?Name=IO-Compress>.

=head1 SEE ALSO

L<Compress::Zlib>, L<IO::Compress::Gzip>, L<IO::Uncompress::Gunzip>, L<IO::Compress::Deflate>, L<IO::Uncompress::Inflate>, L<IO::Compress::RawDeflate>, L<IO::Uncompress::RawInflate>, L<IO::Compress::Bzip2>, L<IO::Uncompress::Bunzip2>, L<IO::Compress::Lzma>, L<IO::Uncompress::UnLzma>, L<IO::Compress::Xz>, L<IO::Uncompress::UnXz>, L<IO::Compress::Lzip>, L<IO::Uncompress::UnLzip>, L<IO::Compress::Lzop>, L<IO::Uncompress::UnLzop>, L<IO::Compress::Lzf>, L<IO::Uncompress::UnLzf>, L<IO::Compress::Zstd>, L<IO::Uncompress::UnZstd>, L<IO::Uncompress::AnyInflate>, L<IO::Uncompress::AnyUncompress>

L<IO::Compress::FAQ|IO::Compress::FAQ>

L<File::GlobMapper|File::GlobMapper>, L<Archive::Zip|Archive::Zip>,
L<Archive::Tar|Archive::Tar>,
L<IO::Zlib|IO::Zlib>

For RFC 1950, 1951 and 1952 see
L<http://www.faqs.org/rfcs/rfc1950.html>,
L<http://www.faqs.org/rfcs/rfc1951.html> and
L<http://www.faqs.org/rfcs/rfc1952.html>

The I<zlib> compression library was written by Jean-loup Gailly
C<gzip@prep.ai.mit.edu> and Mark Adler C<madler@alumni.caltech.edu>.

The primary site for the I<zlib> compression library is
L<http://www.zlib.org>.

The primary site for gzip is L<http://www.gzip.org>.

=head1 AUTHOR

This module was written by Paul Marquess, C<pmqs@cpan.org>.

=head1 MODIFICATION HISTORY

See the Changes file.

=head1 COPYRIGHT AND LICENSE

Copyright (c) 2005-2019 Paul Marquess. All rights reserved.

This program is free software; you can redistribute it and/or
modify it under the same terms as Perl itself.