1Archive::Tar(3) User Contributed Perl Documentation Archive::Tar(3)
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6 Archive::Tar - module for manipulations of tar archives
7
9 use Archive::Tar;
10 my $tar = Archive::Tar->new;
11
12 $tar->read('origin.tgz');
13 $tar->extract();
14
15 $tar->add_files('file/foo.pl', 'docs/README');
16 $tar->add_data('file/baz.txt', 'This is the contents now');
17
18 $tar->rename('oldname', 'new/file/name');
19 $tar->chown('/', 'root');
20 $tar->chown('/', 'root:root');
21 $tar->chmod('/tmp', '1777');
22
23 $tar->write('files.tar'); # plain tar
24 $tar->write('files.tgz', COMPRESS_GZIP); # gzip compressed
25 $tar->write('files.tbz', COMPRESS_BZIP); # bzip2 compressed
26
28 Archive::Tar provides an object oriented mechanism for handling tar
29 files. It provides class methods for quick and easy files handling
30 while also allowing for the creation of tar file objects for custom
31 manipulation. If you have the IO::Zlib module installed, Archive::Tar
32 will also support compressed or gzipped tar files.
33
34 An object of class Archive::Tar represents a .tar(.gz) archive full of
35 files and things.
36
38 Archive::Tar->new( [$file, $compressed] )
39 Returns a new Tar object. If given any arguments, "new()" calls the
40 "read()" method automatically, passing on the arguments provided to the
41 "read()" method.
42
43 If "new()" is invoked with arguments and the "read()" method fails for
44 any reason, "new()" returns undef.
45
46 $tar->read ( $filename|$handle, [$compressed, {opt => 'val'}] )
47 Read the given tar file into memory. The first argument can either be
48 the name of a file or a reference to an already open filehandle (or an
49 IO::Zlib object if it's compressed)
50
51 The "read" will replace any previous content in $tar!
52
53 The second argument may be considered optional, but remains for
54 backwards compatibility. Archive::Tar now looks at the file magic to
55 determine what class should be used to open the file and will
56 transparently Do The Right Thing.
57
58 Archive::Tar will warn if you try to pass a bzip2 compressed file and
59 the IO::Zlib / IO::Uncompress::Bunzip2 modules are not available and
60 simply return.
61
62 Note that you can currently not pass a "gzip" compressed filehandle,
63 which is not opened with "IO::Zlib", a "bzip2" compressed filehandle,
64 which is not opened with "IO::Uncompress::Bunzip2", nor a string
65 containing the full archive information (either compressed or
66 uncompressed). These are worth while features, but not currently
67 implemented. See the "TODO" section.
68
69 The third argument can be a hash reference with options. Note that all
70 options are case-sensitive.
71
72 limit
73 Do not read more than "limit" files. This is useful if you have
74 very big archives, and are only interested in the first few files.
75
76 filter
77 Can be set to a regular expression. Only files with names that
78 match the expression will be read.
79
80 md5 Set to 1 and the md5sum of files will be returned (instead of file
81 data)
82 my $iter = Archive::Tar->iter( $file, 1, {md5 => 1} );
83 while( my $f = $iter->() ) {
84 print $f->data . "\t" . $f->full_path . $/;
85 }
86
87 extract
88 If set to true, immediately extract entries when reading them. This
89 gives you the same memory break as the "extract_archive" function.
90 Note however that entries will not be read into memory, but written
91 straight to disk. This means no "Archive::Tar::File" objects are
92 created for you to inspect.
93
94 All files are stored internally as "Archive::Tar::File" objects.
95 Please consult the Archive::Tar::File documentation for details.
96
97 Returns the number of files read in scalar context, and a list of
98 "Archive::Tar::File" objects in list context.
99
100 $tar->contains_file( $filename )
101 Check if the archive contains a certain file. It will return true if
102 the file is in the archive, false otherwise.
103
104 Note however, that this function does an exact match using "eq" on the
105 full path. So it cannot compensate for case-insensitive file- systems
106 or compare 2 paths to see if they would point to the same underlying
107 file.
108
109 $tar->extract( [@filenames] )
110 Write files whose names are equivalent to any of the names in
111 @filenames to disk, creating subdirectories as necessary. This might
112 not work too well under VMS. Under MacPerl, the file's modification
113 time will be converted to the MacOS zero of time, and appropriate
114 conversions will be done to the path. However, the length of each
115 element of the path is not inspected to see whether it's longer than
116 MacOS currently allows (32 characters).
117
118 If "extract" is called without a list of file names, the entire
119 contents of the archive are extracted.
120
121 Returns a list of filenames extracted.
122
123 $tar->extract_file( $file, [$extract_path] )
124 Write an entry, whose name is equivalent to the file name provided to
125 disk. Optionally takes a second parameter, which is the full native
126 path (including filename) the entry will be written to.
127
128 For example:
129
130 $tar->extract_file( 'name/in/archive', 'name/i/want/to/give/it' );
131
132 $tar->extract_file( $at_file_object, 'name/i/want/to/give/it' );
133
134 Returns true on success, false on failure.
135
136 $tar->list_files( [\@properties] )
137 Returns a list of the names of all the files in the archive.
138
139 If "list_files()" is passed an array reference as its first argument it
140 returns a list of hash references containing the requested properties
141 of each file. The following list of properties is supported: name,
142 size, mtime (last modified date), mode, uid, gid, linkname, uname,
143 gname, devmajor, devminor, prefix.
144
145 Passing an array reference containing only one element, 'name', is
146 special cased to return a list of names rather than a list of hash
147 references, making it equivalent to calling "list_files" without
148 arguments.
149
150 $tar->get_files( [@filenames] )
151 Returns the "Archive::Tar::File" objects matching the filenames
152 provided. If no filename list was passed, all "Archive::Tar::File"
153 objects in the current Tar object are returned.
154
155 Please refer to the "Archive::Tar::File" documentation on how to handle
156 these objects.
157
158 $tar->get_content( $file )
159 Return the content of the named file.
160
161 $tar->replace_content( $file, $content )
162 Make the string $content be the content for the file named $file.
163
164 $tar->rename( $file, $new_name )
165 Rename the file of the in-memory archive to $new_name.
166
167 Note that you must specify a Unix path for $new_name, since per tar
168 standard, all files in the archive must be Unix paths.
169
170 Returns true on success and false on failure.
171
172 $tar->chmod( $file, $mode )
173 Change mode of $file to $mode.
174
175 Returns true on success and false on failure.
176
177 $tar->chown( $file, $uname [, $gname] )
178 Change owner $file to $uname and $gname.
179
180 Returns true on success and false on failure.
181
182 $tar->remove (@filenamelist)
183 Removes any entries with names matching any of the given filenames from
184 the in-memory archive. Returns a list of "Archive::Tar::File" objects
185 that remain.
186
187 $tar->clear
188 "clear" clears the current in-memory archive. This effectively gives
189 you a 'blank' object, ready to be filled again. Note that "clear" only
190 has effect on the object, not the underlying tarfile.
191
192 $tar->write ( [$file, $compressed, $prefix] )
193 Write the in-memory archive to disk. The first argument can either be
194 the name of a file or a reference to an already open filehandle (a GLOB
195 reference).
196
197 The second argument is used to indicate compression. You can either
198 compress using "gzip" or "bzip2". If you pass a digit, it's assumed to
199 be the "gzip" compression level (between 1 and 9), but the use of
200 constants is preferred:
201
202 # write a gzip compressed file
203 $tar->write( 'out.tgz', COMPRESS_GZIP );
204
205 # write a bzip compressed file
206 $tar->write( 'out.tbz', COMPRESS_BZIP );
207
208 Note that when you pass in a filehandle, the compression argument is
209 ignored, as all files are printed verbatim to your filehandle. If you
210 wish to enable compression with filehandles, use an "IO::Zlib" or
211 "IO::Compress::Bzip2" filehandle instead.
212
213 The third argument is an optional prefix. All files will be tucked away
214 in the directory you specify as prefix. So if you have files 'a' and
215 'b' in your archive, and you specify 'foo' as prefix, they will be
216 written to the archive as 'foo/a' and 'foo/b'.
217
218 If no arguments are given, "write" returns the entire formatted archive
219 as a string, which could be useful if you'd like to stuff the archive
220 into a socket or a pipe to gzip or something.
221
222 $tar->add_files( @filenamelist )
223 Takes a list of filenames and adds them to the in-memory archive.
224
225 The path to the file is automatically converted to a Unix like
226 equivalent for use in the archive, and, if on MacOS, the file's
227 modification time is converted from the MacOS epoch to the Unix epoch.
228 So tar archives created on MacOS with Archive::Tar can be read both
229 with tar on Unix and applications like suntar or Stuffit Expander on
230 MacOS.
231
232 Be aware that the file's type/creator and resource fork will be lost,
233 which is usually what you want in cross-platform archives.
234
235 Instead of a filename, you can also pass it an existing
236 "Archive::Tar::File" object from, for example, another archive. The
237 object will be clone, and effectively be a copy of the original, not an
238 alias.
239
240 Returns a list of "Archive::Tar::File" objects that were just added.
241
242 $tar->add_data ( $filename, $data, [$opthashref] )
243 Takes a filename, a scalar full of data and optionally a reference to a
244 hash with specific options.
245
246 Will add a file to the in-memory archive, with name $filename and
247 content $data. Specific properties can be set using $opthashref. The
248 following list of properties is supported: name, size, mtime (last
249 modified date), mode, uid, gid, linkname, uname, gname, devmajor,
250 devminor, prefix, type. (On MacOS, the file's path and modification
251 times are converted to Unix equivalents.)
252
253 Valid values for the file type are the following constants defined by
254 Archive::Tar::Constant:
255
256 FILE
257 Regular file.
258
259 HARDLINK
260 SYMLINK
261 Hard and symbolic ("soft") links; linkname should specify target.
262
263 CHARDEV
264 BLOCKDEV
265 Character and block devices. devmajor and devminor should specify
266 the major and minor device numbers.
267
268 DIR Directory.
269
270 FIFO
271 FIFO (named pipe).
272
273 SOCKET
274 Socket.
275
276 Returns the "Archive::Tar::File" object that was just added, or "undef"
277 on failure.
278
279 $tar->error( [$BOOL] )
280 Returns the current error string (usually, the last error reported).
281 If a true value was specified, it will give the "Carp::longmess"
282 equivalent of the error, in effect giving you a stacktrace.
283
284 For backwards compatibility, this error is also available as
285 $Archive::Tar::error although it is much recommended you use the method
286 call instead.
287
288 $tar->setcwd( $cwd );
289 "Archive::Tar" needs to know the current directory, and it will run
290 "Cwd::cwd()" every time it extracts a relative entry from the tarfile
291 and saves it in the file system. (As of version 1.30, however,
292 "Archive::Tar" will use the speed optimization described below
293 automatically, so it's only relevant if you're using "extract_file()").
294
295 Since "Archive::Tar" doesn't change the current directory internally
296 while it is extracting the items in a tarball, all calls to
297 "Cwd::cwd()" can be avoided if we can guarantee that the current
298 directory doesn't get changed externally.
299
300 To use this performance boost, set the current directory via
301
302 use Cwd;
303 $tar->setcwd( cwd() );
304
305 once before calling a function like "extract_file" and "Archive::Tar"
306 will use the current directory setting from then on and won't call
307 "Cwd::cwd()" internally.
308
309 To switch back to the default behaviour, use
310
311 $tar->setcwd( undef );
312
313 and "Archive::Tar" will call "Cwd::cwd()" internally again.
314
315 If you're using "Archive::Tar"'s "extract()" method, "setcwd()" will be
316 called for you.
317
319 Archive::Tar->create_archive($file, $compressed, @filelist)
320 Creates a tar file from the list of files provided. The first argument
321 can either be the name of the tar file to create or a reference to an
322 open file handle (e.g. a GLOB reference).
323
324 The second argument is used to indicate compression. You can either
325 compress using "gzip" or "bzip2". If you pass a digit, it's assumed to
326 be the "gzip" compression level (between 1 and 9), but the use of
327 constants is preferred:
328
329 # write a gzip compressed file
330 Archive::Tar->create_archive( 'out.tgz', COMPRESS_GZIP, @filelist );
331
332 # write a bzip compressed file
333 Archive::Tar->create_archive( 'out.tbz', COMPRESS_BZIP, @filelist );
334
335 Note that when you pass in a filehandle, the compression argument is
336 ignored, as all files are printed verbatim to your filehandle. If you
337 wish to enable compression with filehandles, use an "IO::Zlib" or
338 "IO::Compress::Bzip2" filehandle instead.
339
340 The remaining arguments list the files to be included in the tar file.
341 These files must all exist. Any files which don't exist or can't be
342 read are silently ignored.
343
344 If the archive creation fails for any reason, "create_archive" will
345 return false. Please use the "error" method to find the cause of the
346 failure.
347
348 Note that this method does not write "on the fly" as it were; it still
349 reads all the files into memory before writing out the archive.
350 Consult the FAQ below if this is a problem.
351
352 Archive::Tar->iter( $filename, [ $compressed, {opt => $val} ] )
353 Returns an iterator function that reads the tar file without loading it
354 all in memory. Each time the function is called it will return the
355 next file in the tarball. The files are returned as
356 "Archive::Tar::File" objects. The iterator function returns the empty
357 list once it has exhausted the files contained.
358
359 The second argument can be a hash reference with options, which are
360 identical to the arguments passed to "read()".
361
362 Example usage:
363
364 my $next = Archive::Tar->iter( "example.tar.gz", 1, {filter => qr/\.pm$/} );
365
366 while( my $f = $next->() ) {
367 print $f->name, "\n";
368
369 $f->extract or warn "Extraction failed";
370
371 # ....
372 }
373
374 Archive::Tar->list_archive($file, $compressed, [\@properties])
375 Returns a list of the names of all the files in the archive. The first
376 argument can either be the name of the tar file to list or a reference
377 to an open file handle (e.g. a GLOB reference).
378
379 If "list_archive()" is passed an array reference as its third argument
380 it returns a list of hash references containing the requested
381 properties of each file. The following list of properties is
382 supported: full_path, name, size, mtime (last modified date), mode,
383 uid, gid, linkname, uname, gname, devmajor, devminor, prefix, type.
384
385 See "Archive::Tar::File" for details about supported properties.
386
387 Passing an array reference containing only one element, 'name', is
388 special cased to return a list of names rather than a list of hash
389 references.
390
391 Archive::Tar->extract_archive($file, $compressed)
392 Extracts the contents of the tar file. The first argument can either
393 be the name of the tar file to create or a reference to an open file
394 handle (e.g. a GLOB reference). All relative paths in the tar file
395 will be created underneath the current working directory.
396
397 "extract_archive" will return a list of files it extracted. If the
398 archive extraction fails for any reason, "extract_archive" will return
399 false. Please use the "error" method to find the cause of the failure.
400
401 $bool = Archive::Tar->has_io_string
402 Returns true if we currently have "IO::String" support loaded.
403
404 Either "IO::String" or "perlio" support is needed to support writing
405 stringified archives. Currently, "perlio" is the preferred method, if
406 available.
407
408 See the "GLOBAL VARIABLES" section to see how to change this
409 preference.
410
411 $bool = Archive::Tar->has_perlio
412 Returns true if we currently have "perlio" support loaded.
413
414 This requires "perl-5.8" or higher, compiled with "perlio"
415
416 Either "IO::String" or "perlio" support is needed to support writing
417 stringified archives. Currently, "perlio" is the preferred method, if
418 available.
419
420 See the "GLOBAL VARIABLES" section to see how to change this
421 preference.
422
423 $bool = Archive::Tar->has_zlib_support
424 Returns true if "Archive::Tar" can extract "zlib" compressed archives
425
426 $bool = Archive::Tar->has_bzip2_support
427 Returns true if "Archive::Tar" can extract "bzip2" compressed archives
428
429 Archive::Tar->can_handle_compressed_files
430 A simple checking routine, which will return true if "Archive::Tar" is
431 able to uncompress compressed archives on the fly with "IO::Zlib" and
432 "IO::Compress::Bzip2" or false if not both are installed.
433
434 You can use this as a shortcut to determine whether "Archive::Tar" will
435 do what you think before passing compressed archives to its "read"
436 method.
437
439 $Archive::Tar::FOLLOW_SYMLINK
440 Set this variable to 1 to make "Archive::Tar" effectively make a copy
441 of the file when extracting. Default is 0, which means the symlink
442 stays intact. Of course, you will have to pack the file linked to as
443 well.
444
445 This option is checked when you write out the tarfile using "write" or
446 "create_archive".
447
448 This works just like "/bin/tar"'s "-h" option.
449
450 $Archive::Tar::CHOWN
451 By default, "Archive::Tar" will try to "chown" your files if it is able
452 to. In some cases, this may not be desired. In that case, set this
453 variable to 0 to disable "chown"-ing, even if it were possible.
454
455 The default is 1.
456
457 $Archive::Tar::CHMOD
458 By default, "Archive::Tar" will try to "chmod" your files to whatever
459 mode was specified for the particular file in the archive. In some
460 cases, this may not be desired. In that case, set this variable to 0 to
461 disable "chmod"-ing.
462
463 The default is 1.
464
465 $Archive::Tar::SAME_PERMISSIONS
466 When, $Archive::Tar::CHMOD is enabled, this setting controls whether
467 the permissions on files from the archive are used without modification
468 of if they are filtered by removing any setid bits and applying the
469 current umask.
470
471 The default is 1 for the root user and 0 for normal users.
472
473 $Archive::Tar::DO_NOT_USE_PREFIX
474 By default, "Archive::Tar" will try to put paths that are over 100
475 characters in the "prefix" field of your tar header, as defined per
476 POSIX-standard. However, some (older) tar programs do not implement
477 this spec. To retain compatibility with these older or non-POSIX
478 compliant versions, you can set the $DO_NOT_USE_PREFIX variable to a
479 true value, and "Archive::Tar" will use an alternate way of dealing
480 with paths over 100 characters by using the "GNU Extended Header"
481 feature.
482
483 Note that clients who do not support the "GNU Extended Header" feature
484 will not be able to read these archives. Such clients include tars on
485 "Solaris", "Irix" and "AIX".
486
487 The default is 0.
488
489 $Archive::Tar::DEBUG
490 Set this variable to 1 to always get the "Carp::longmess" output of the
491 warnings, instead of the regular "carp". This is the same message you
492 would get by doing:
493
494 $tar->error(1);
495
496 Defaults to 0.
497
498 $Archive::Tar::WARN
499 Set this variable to 0 if you do not want any warnings printed.
500 Personally I recommend against doing this, but people asked for the
501 option. Also, be advised that this is of course not threadsafe.
502
503 Defaults to 1.
504
505 $Archive::Tar::error
506 Holds the last reported error. Kept for historical reasons, but its use
507 is very much discouraged. Use the "error()" method instead:
508
509 warn $tar->error unless $tar->extract;
510
511 Note that in older versions of this module, the "error()" method would
512 return an effectively global value even when called an instance method
513 as above. This has since been fixed, and multiple instances of
514 "Archive::Tar" now have separate error strings.
515
516 $Archive::Tar::INSECURE_EXTRACT_MODE
517 This variable indicates whether "Archive::Tar" should allow files to be
518 extracted outside their current working directory.
519
520 Allowing this could have security implications, as a malicious tar
521 archive could alter or replace any file the extracting user has
522 permissions to. Therefor, the default is to not allow insecure
523 extractions.
524
525 If you trust the archive, or have other reasons to allow the archive to
526 write files outside your current working directory, set this variable
527 to "true".
528
529 Note that this is a backwards incompatible change from version 1.36 and
530 before.
531
532 $Archive::Tar::HAS_PERLIO
533 This variable holds a boolean indicating if we currently have "perlio"
534 support loaded. This will be enabled for any perl greater than 5.8
535 compiled with "perlio".
536
537 If you feel strongly about disabling it, set this variable to "false".
538 Note that you will then need "IO::String" installed to support writing
539 stringified archives.
540
541 Don't change this variable unless you really know what you're doing.
542
543 $Archive::Tar::HAS_IO_STRING
544 This variable holds a boolean indicating if we currently have
545 "IO::String" support loaded. This will be enabled for any perl that has
546 a loadable "IO::String" module.
547
548 If you feel strongly about disabling it, set this variable to "false".
549 Note that you will then need "perlio" support from your perl to be able
550 to write stringified archives.
551
552 Don't change this variable unless you really know what you're doing.
553
554 $Archive::Tar::ZERO_PAD_NUMBERS
555 This variable holds a boolean indicating if we will create zero padded
556 numbers for "size", "mtime" and "checksum". The default is 0,
557 indicating that we will create space padded numbers. Added for
558 compatibility with "busybox" implementations.
559
560 Tuning the way RESOLVE_SYMLINK will works
561 You can tune the behaviour by setting the $Archive::Tar::RESOLVE_SYMLINK variable,
562 or $ENV{PERL5_AT_RESOLVE_SYMLINK} before loading the module Archive::Tar.
563
564 Values can be one of the following:
565
566 none
567 Disable this mechanism and failed as it was in previous version (<1.88)
568
569 speed (default)
570 If you prefer speed
571 this will read again the whole archive using read() so all entries
572 will be available
573
574 memory
575 If you prefer memory
576
577 Limitation
578
579 It won't work for terminal, pipe or sockets or every non seekable source.
580
582 What's the minimum perl version required to run Archive::Tar?
583 You will need perl version 5.005_03 or newer.
584
585 Isn't Archive::Tar slow?
586 Yes it is. It's pure perl, so it's a lot slower then your
587 "/bin/tar" However, it's very portable. If speed is an issue,
588 consider using "/bin/tar" instead.
589
590 Isn't Archive::Tar heavier on memory than /bin/tar?
591 Yes it is, see previous answer. Since "Compress::Zlib" and
592 therefore "IO::Zlib" doesn't support "seek" on their filehandles,
593 there is little choice but to read the archive into memory. This
594 is ok if you want to do in-memory manipulation of the archive.
595
596 If you just want to extract, use the "extract_archive" class method
597 instead. It will optimize and write to disk immediately.
598
599 Another option is to use the "iter" class method to iterate over
600 the files in the tarball without reading them all in memory at
601 once.
602
603 Can you lazy-load data instead?
604 In some cases, yes. You can use the "iter" class method to iterate
605 over the files in the tarball without reading them all in memory at
606 once.
607
608 How much memory will an X kb tar file need?
609 Probably more than X kb, since it will all be read into memory. If
610 this is a problem, and you don't need to do in memory manipulation
611 of the archive, consider using the "iter" class method, or
612 "/bin/tar" instead.
613
614 What do you do with unsupported filetypes in an archive?
615 "Unix" has a few filetypes that aren't supported on other
616 platforms, like "Win32". If we encounter a "hardlink" or "symlink"
617 we'll just try to make a copy of the original file, rather than
618 throwing an error.
619
620 This does require you to read the entire archive in to memory
621 first, since otherwise we wouldn't know what data to fill the copy
622 with. (This means that you cannot use the class methods, including
623 "iter" on archives that have incompatible filetypes and still
624 expect things to work).
625
626 For other filetypes, like "chardevs" and "blockdevs" we'll warn
627 that the extraction of this particular item didn't work.
628
629 I'm using WinZip, or some other non-POSIX client, and files are not
630 being extracted properly!
631 By default, "Archive::Tar" is in a completely POSIX-compatible
632 mode, which uses the POSIX-specification of "tar" to store files.
633 For paths greater than 100 characters, this is done using the
634 "POSIX header prefix". Non-POSIX-compatible clients may not support
635 this part of the specification, and may only support the "GNU
636 Extended Header" functionality. To facilitate those clients, you
637 can set the $Archive::Tar::DO_NOT_USE_PREFIX variable to "true".
638 See the "GLOBAL VARIABLES" section for details on this variable.
639
640 Note that GNU tar earlier than version 1.14 does not cope well with
641 the "POSIX header prefix". If you use such a version, consider
642 setting the $Archive::Tar::DO_NOT_USE_PREFIX variable to "true".
643
644 How do I extract only files that have property X from an archive?
645 Sometimes, you might not wish to extract a complete archive, just
646 the files that are relevant to you, based on some criteria.
647
648 You can do this by filtering a list of "Archive::Tar::File" objects
649 based on your criteria. For example, to extract only files that
650 have the string "foo" in their title, you would use:
651
652 $tar->extract(
653 grep { $_->full_path =~ /foo/ } $tar->get_files
654 );
655
656 This way, you can filter on any attribute of the files in the
657 archive. Consult the "Archive::Tar::File" documentation on how to
658 use these objects.
659
660 How do I access .tar.Z files?
661 The "Archive::Tar" module can optionally use "Compress::Zlib" (via
662 the "IO::Zlib" module) to access tar files that have been
663 compressed with "gzip". Unfortunately tar files compressed with the
664 Unix "compress" utility cannot be read by "Compress::Zlib" and so
665 cannot be directly accesses by "Archive::Tar".
666
667 If the "uncompress" or "gunzip" programs are available, you can use
668 one of these workarounds to read ".tar.Z" files from "Archive::Tar"
669
670 Firstly with "uncompress"
671
672 use Archive::Tar;
673
674 open F, "uncompress -c $filename |";
675 my $tar = Archive::Tar->new(*F);
676 ...
677
678 and this with "gunzip"
679
680 use Archive::Tar;
681
682 open F, "gunzip -c $filename |";
683 my $tar = Archive::Tar->new(*F);
684 ...
685
686 Similarly, if the "compress" program is available, you can use this
687 to write a ".tar.Z" file
688
689 use Archive::Tar;
690 use IO::File;
691
692 my $fh = new IO::File "| compress -c >$filename";
693 my $tar = Archive::Tar->new();
694 ...
695 $tar->write($fh);
696 $fh->close ;
697
698 How do I handle Unicode strings?
699 "Archive::Tar" uses byte semantics for any files it reads from or
700 writes to disk. This is not a problem if you only deal with files
701 and never look at their content or work solely with byte strings.
702 But if you use Unicode strings with character semantics, some
703 additional steps need to be taken.
704
705 For example, if you add a Unicode string like
706
707 # Problem
708 $tar->add_data('file.txt', "Euro: \x{20AC}");
709
710 then there will be a problem later when the tarfile gets written
711 out to disk via "$tar->write()":
712
713 Wide character in print at .../Archive/Tar.pm line 1014.
714
715 The data was added as a Unicode string and when writing it out to
716 disk, the ":utf8" line discipline wasn't set by "Archive::Tar", so
717 Perl tried to convert the string to ISO-8859 and failed. The
718 written file now contains garbage.
719
720 For this reason, Unicode strings need to be converted to
721 UTF-8-encoded bytestrings before they are handed off to
722 "add_data()":
723
724 use Encode;
725 my $data = "Accented character: \x{20AC}";
726 $data = encode('utf8', $data);
727
728 $tar->add_data('file.txt', $data);
729
730 A opposite problem occurs if you extract a UTF8-encoded file from a
731 tarball. Using "get_content()" on the "Archive::Tar::File" object
732 will return its content as a bytestring, not as a Unicode string.
733
734 If you want it to be a Unicode string (because you want character
735 semantics with operations like regular expression matching), you
736 need to decode the UTF8-encoded content and have Perl convert it
737 into a Unicode string:
738
739 use Encode;
740 my $data = $tar->get_content();
741
742 # Make it a Unicode string
743 $data = decode('utf8', $data);
744
745 There is no easy way to provide this functionality in
746 "Archive::Tar", because a tarball can contain many files, and each
747 of which could be encoded in a different way.
748
750 The AIX tar does not fill all unused space in the tar archive with
751 0x00. This sometimes leads to warning messages from "Archive::Tar".
752
753 Invalid header block at offset nnn
754
755 A fix for that problem is scheduled to be released in the following
756 levels of AIX, all of which should be coming out in the 4th quarter of
757 2009:
758
759 AIX 5.3 TL7 SP10
760 AIX 5.3 TL8 SP8
761 AIX 5.3 TL9 SP5
762 AIX 5.3 TL10 SP2
763
764 AIX 6.1 TL0 SP11
765 AIX 6.1 TL1 SP7
766 AIX 6.1 TL2 SP6
767 AIX 6.1 TL3 SP3
768
769 The IBM APAR number for this problem is IZ50240 (Reported component ID:
770 5765G0300 / AIX 5.3). It is possible to get an ifix for that problem.
771 If you need an ifix please contact your local IBM AIX support.
772
774 Check if passed in handles are open for read/write
775 Currently I don't know of any portable pure perl way to do this.
776 Suggestions welcome.
777
778 Allow archives to be passed in as string
779 Currently, we only allow opened filehandles or filenames, but not
780 strings. The internals would need some reworking to facilitate
781 stringified archives.
782
783 Facilitate processing an opened filehandle of a compressed archive
784 Currently, we only support this if the filehandle is an IO::Zlib
785 object. Environments, like apache, will present you with an opened
786 filehandle to an uploaded file, which might be a compressed
787 archive.
788
790 The GNU tar specification
791 "http://www.gnu.org/software/tar/manual/tar.html"
792
793 The PAX format specification
794 The specification which tar derives from; "
795 http://www.opengroup.org/onlinepubs/007904975/utilities/pax.html"
796
797 A comparison of GNU and POSIX tar standards;
798 "http://www.delorie.com/gnu/docs/tar/tar_114.html"
799 GNU tar intends to switch to POSIX compatibility
800 GNU Tar authors have expressed their intention to become completely
801 POSIX-compatible;
802 "http://www.gnu.org/software/tar/manual/html_node/Formats.html"
803
804 A Comparison between various tar implementations
805 Lists known issues and incompatibilities;
806 "http://gd.tuwien.ac.at/utils/archivers/star/README.otherbugs"
807
809 This module by Jos Boumans <kane@cpan.org>.
810
811 Please reports bugs to <bug-archive-tar@rt.cpan.org>.
812
814 Thanks to Sean Burke, Chris Nandor, Chip Salzenberg, Tim Heaney, Gisle
815 Aas, Rainer Tammer and especially Andrew Savige for their help and
816 suggestions.
817
819 This module is copyright (c) 2002 - 2009 Jos Boumans <kane@cpan.org>.
820 All rights reserved.
821
822 This library is free software; you may redistribute and/or modify it
823 under the same terms as Perl itself.
824
825
826
827perl v5.28.0 2018-06-19 Archive::Tar(3)