Archive::Tar - module for manipulations of tar archives
- use Archive::Tar;
- my $tar = Archive::Tar->new;
- $tar->read('origin.tgz');
- $tar->extract();
- $tar->add_files('file/foo.pl', 'docs/README');
- $tar->add_data('file/baz.txt', 'This is the contents now');
- $tar->rename('oldname', 'new/file/name');
- $tar->chown('/', 'root');
- $tar->chown('/', 'root:root');
- $tar->chmod('/tmp', '1777');
- $tar->write('files.tar'); # plain tar
- $tar->write('files.tgz', COMPRESS_GZIP); # gzip compressed
- $tar->write('files.tbz', COMPRESS_BZIP); # bzip2 compressed
Archive::Tar provides an object oriented mechanism for handling tar files. It provides class methods for quick and easy files handling while also allowing for the creation of tar file objects for custom manipulation. If you have the IO::Zlib module installed, Archive::Tar will also support compressed or gzipped tar files.
An object of class Archive::Tar represents a .tar(.gz) archive full of files and things.
Returns a new Tar object. If given any arguments, new()
calls the
read() method automatically, passing on the arguments provided to
the read() method.
If new()
is invoked with arguments and the read() method fails
for any reason, new()
returns undef.
Read the given tar file into memory. The first argument can either be the name of a file or a reference to an already open filehandle (or an IO::Zlib object if it's compressed)
The read will replace any previous content in $tar
!
The second argument may be considered optional, but remains for backwards compatibility. Archive::Tar now looks at the file magic to determine what class should be used to open the file and will transparently Do The Right Thing.
Archive::Tar will warn if you try to pass a bzip2 compressed file and the IO::Zlib / IO::Uncompress::Bunzip2 modules are not available and simply return.
Note that you can currently not pass a gzip
compressed
filehandle, which is not opened with IO::Zlib
, a bzip2
compressed
filehandle, which is not opened with IO::Uncompress::Bunzip2
, nor a string
containing the full archive information (either compressed or
uncompressed). These are worth while features, but not currently
implemented. See the TODO
section.
The third argument can be a hash reference with options. Note that all options are case-sensitive.
Do not read more than limit
files. This is useful if you have
very big archives, and are only interested in the first few files.
Can be set to a regular expression. Only files with names that match the expression will be read.
Set to 1 and the md5sum of files will be returned (instead of file data) my $iter = Archive::Tar->iter( $file, 1, {md5 => 1} ); while( my $f = $iter->() ) { print $f->data . "\t" . $f->full_path . $/; }
If set to true, immediately extract entries when reading them. This
gives you the same memory break as the extract_archive
function.
Note however that entries will not be read into memory, but written
straight to disk. This means no Archive::Tar::File
objects are
created for you to inspect.
All files are stored internally as Archive::Tar::File
objects.
Please consult the Archive::Tar::File documentation for details.
Returns the number of files read in scalar context, and a list of
Archive::Tar::File
objects in list context.
Check if the archive contains a certain file. It will return true if the file is in the archive, false otherwise.
Note however, that this function does an exact match using eq
on the full path. So it cannot compensate for case-insensitive file-
systems or compare 2 paths to see if they would point to the same
underlying file.
Write files whose names are equivalent to any of the names in
@filenames
to disk, creating subdirectories as necessary. This
might not work too well under VMS.
Under MacPerl, the file's modification time will be converted to the
MacOS zero of time, and appropriate conversions will be done to the
path. However, the length of each element of the path is not
inspected to see whether it's longer than MacOS currently allows (32
characters).
If extract
is called without a list of file names, the entire
contents of the archive are extracted.
Returns a list of filenames extracted.
Write an entry, whose name is equivalent to the file name provided to disk. Optionally takes a second parameter, which is the full native path (including filename) the entry will be written to.
For example:
- $tar->extract_file( 'name/in/archive', 'name/i/want/to/give/it' );
- $tar->extract_file( $at_file_object, 'name/i/want/to/give/it' );
Returns true on success, false on failure.
Returns a list of the names of all the files in the archive.
If list_files()
is passed an array reference as its first argument
it returns a list of hash references containing the requested
properties of each file. The following list of properties is
supported: name, size, mtime (last modified date), mode, uid, gid,
linkname, uname, gname, devmajor, devminor, prefix.
Passing an array reference containing only one element, 'name', is
special cased to return a list of names rather than a list of hash
references, making it equivalent to calling list_files
without
arguments.
Returns the Archive::Tar::File
objects matching the filenames
provided. If no filename list was passed, all Archive::Tar::File
objects in the current Tar object are returned.
Please refer to the Archive::Tar::File
documentation on how to
handle these objects.
Return the content of the named file.
Make the string $content be the content for the file named $file.
Rename the file of the in-memory archive to $new_name.
Note that you must specify a Unix path for $new_name, since per tar standard, all files in the archive must be Unix paths.
Returns true on success and false on failure.
Change mode of $file to $mode.
Returns true on success and false on failure.
Change owner $file to $uname and $gname.
Returns true on success and false on failure.
Removes any entries with names matching any of the given filenames
from the in-memory archive. Returns a list of Archive::Tar::File
objects that remain.
clear
clears the current in-memory archive. This effectively gives
you a 'blank' object, ready to be filled again. Note that clear
only has effect on the object, not the underlying tarfile.
Write the in-memory archive to disk. The first argument can either be the name of a file or a reference to an already open filehandle (a GLOB reference).
The second argument is used to indicate compression. You can either
compress using gzip
or bzip2
. If you pass a digit, it's assumed
to be the gzip
compression level (between 1 and 9), but the use of
constants is preferred:
- # write a gzip compressed file
- $tar->write( 'out.tgz', COMPRESS_GZIP );
- # write a bzip compressed file
- $tar->write( 'out.tbz', COMPRESS_BZIP );
Note that when you pass in a filehandle, the compression argument
is ignored, as all files are printed verbatim to your filehandle.
If you wish to enable compression with filehandles, use an
IO::Zlib
or IO::Compress::Bzip2
filehandle instead.
The third argument is an optional prefix. All files will be tucked away in the directory you specify as prefix. So if you have files 'a' and 'b' in your archive, and you specify 'foo' as prefix, they will be written to the archive as 'foo/a' and 'foo/b'.
If no arguments are given, write returns the entire formatted
archive as a string, which could be useful if you'd like to stuff the
archive into a socket or a pipe to gzip or something.
Takes a list of filenames and adds them to the in-memory archive.
The path to the file is automatically converted to a Unix like equivalent for use in the archive, and, if on MacOS, the file's modification time is converted from the MacOS epoch to the Unix epoch. So tar archives created on MacOS with Archive::Tar can be read both with tar on Unix and applications like suntar or Stuffit Expander on MacOS.
Be aware that the file's type/creator and resource fork will be lost, which is usually what you want in cross-platform archives.
Instead of a filename, you can also pass it an existing Archive::Tar::File
object from, for example, another archive. The object will be clone, and
effectively be a copy of the original, not an alias.
Returns a list of Archive::Tar::File
objects that were just added.
Takes a filename, a scalar full of data and optionally a reference to a hash with specific options.
Will add a file to the in-memory archive, with name $filename
and
content $data
. Specific properties can be set using $opthashref
.
The following list of properties is supported: name, size, mtime
(last modified date), mode, uid, gid, linkname, uname, gname,
devmajor, devminor, prefix, type. (On MacOS, the file's path and
modification times are converted to Unix equivalents.)
Valid values for the file type are the following constants defined by Archive::Tar::Constant:
Regular file.
Hard and symbolic ("soft") links; linkname should specify target.
Character and block devices. devmajor and devminor should specify the major and minor device numbers.
Directory.
FIFO (named pipe).
Socket.
Returns the Archive::Tar::File
object that was just added, or
undef on failure.
Returns the current errorstring (usually, the last error reported).
If a true value was specified, it will give the Carp::longmess
equivalent of the error, in effect giving you a stacktrace.
For backwards compatibility, this error is also available as
$Archive::Tar::error
although it is much recommended you use the
method call instead.
Archive::Tar
needs to know the current directory, and it will run
Cwd::cwd()
every time it extracts a relative entry from the
tarfile and saves it in the file system. (As of version 1.30, however,
Archive::Tar
will use the speed optimization described below
automatically, so it's only relevant if you're using extract_file()
).
Since Archive::Tar
doesn't change the current directory internally
while it is extracting the items in a tarball, all calls to Cwd::cwd()
can be avoided if we can guarantee that the current directory doesn't
get changed externally.
To use this performance boost, set the current directory via
- use Cwd;
- $tar->setcwd( cwd() );
once before calling a function like extract_file
and
Archive::Tar
will use the current directory setting from then on
and won't call Cwd::cwd()
internally.
To switch back to the default behaviour, use
- $tar->setcwd( undef );
and Archive::Tar
will call Cwd::cwd()
internally again.
If you're using Archive::Tar
's extract()
method, setcwd()
will
be called for you.
Creates a tar file from the list of files provided. The first argument can either be the name of the tar file to create or a reference to an open file handle (e.g. a GLOB reference).
The second argument is used to indicate compression. You can either
compress using gzip
or bzip2
. If you pass a digit, it's assumed
to be the gzip
compression level (between 1 and 9), but the use of
constants is preferred:
- # write a gzip compressed file
- Archive::Tar->create_archive( 'out.tgz', COMPRESS_GZIP, @filelist );
- # write a bzip compressed file
- Archive::Tar->create_archive( 'out.tbz', COMPRESS_BZIP, @filelist );
Note that when you pass in a filehandle, the compression argument
is ignored, as all files are printed verbatim to your filehandle.
If you wish to enable compression with filehandles, use an
IO::Zlib
or IO::Compress::Bzip2
filehandle instead.
The remaining arguments list the files to be included in the tar file. These files must all exist. Any files which don't exist or can't be read are silently ignored.
If the archive creation fails for any reason, create_archive
will
return false. Please use the error
method to find the cause of the
failure.
Note that this method does not write on the fly
as it were; it
still reads all the files into memory before writing out the archive.
Consult the FAQ below if this is a problem.
Returns an iterator function that reads the tar file without loading
it all in memory. Each time the function is called it will return the
next file in the tarball. The files are returned as
Archive::Tar::File
objects. The iterator function returns the
empty list once it has exhausted the files contained.
The second argument can be a hash reference with options, which are
identical to the arguments passed to read().
Example usage:
Returns a list of the names of all the files in the archive. The first argument can either be the name of the tar file to list or a reference to an open file handle (e.g. a GLOB reference).
If list_archive()
is passed an array reference as its third
argument it returns a list of hash references containing the requested
properties of each file. The following list of properties is
supported: full_path, name, size, mtime (last modified date), mode,
uid, gid, linkname, uname, gname, devmajor, devminor, prefix, type.
See Archive::Tar::File
for details about supported properties.
Passing an array reference containing only one element, 'name', is special cased to return a list of names rather than a list of hash references.
Extracts the contents of the tar file. The first argument can either be the name of the tar file to create or a reference to an open file handle (e.g. a GLOB reference). All relative paths in the tar file will be created underneath the current working directory.
extract_archive
will return a list of files it extracted.
If the archive extraction fails for any reason, extract_archive
will return false. Please use the error
method to find the cause
of the failure.
Returns true if we currently have IO::String
support loaded.
Either IO::String
or perlio
support is needed to support writing
stringified archives. Currently, perlio
is the preferred method, if
available.
See the GLOBAL VARIABLES
section to see how to change this preference.
Returns true if we currently have perlio
support loaded.
This requires perl-5.8
or higher, compiled with perlio
Either IO::String
or perlio
support is needed to support writing
stringified archives. Currently, perlio
is the preferred method, if
available.
See the GLOBAL VARIABLES
section to see how to change this preference.
Returns true if Archive::Tar
can extract zlib
compressed archives
Returns true if Archive::Tar
can extract bzip2
compressed archives
A simple checking routine, which will return true if Archive::Tar
is able to uncompress compressed archives on the fly with IO::Zlib
and IO::Compress::Bzip2
or false if not both are installed.
You can use this as a shortcut to determine whether Archive::Tar
will do what you think before passing compressed archives to its
read method.
Set this variable to 1
to make Archive::Tar
effectively make a
copy of the file when extracting. Default is 0
, which
means the symlink stays intact. Of course, you will have to pack the
file linked to as well.
This option is checked when you write out the tarfile using write
or create_archive
.
This works just like /bin/tar's -h
option.
By default, Archive::Tar
will try to chown your files if it is
able to. In some cases, this may not be desired. In that case, set
this variable to 0
to disable chown-ing, even if it were
possible.
The default is 1
.
By default, Archive::Tar
will try to chmod your files to
whatever mode was specified for the particular file in the archive.
In some cases, this may not be desired. In that case, set this
variable to 0
to disable chmod-ing.
The default is 1
.
When, $Archive::Tar::CHMOD
is enabled, this setting controls whether
the permissions on files from the archive are used without modification
of if they are filtered by removing any setid bits and applying the
current umask.
The default is 1
for the root user and 0
for normal users.
By default, Archive::Tar
will try to put paths that are over
100 characters in the prefix
field of your tar header, as
defined per POSIX-standard. However, some (older) tar programs
do not implement this spec. To retain compatibility with these older
or non-POSIX compliant versions, you can set the $DO_NOT_USE_PREFIX
variable to a true value, and Archive::Tar
will use an alternate
way of dealing with paths over 100 characters by using the
GNU Extended Header
feature.
Note that clients who do not support the GNU Extended Header
feature will not be able to read these archives. Such clients include
tars on Solaris
, Irix
and AIX
.
The default is 0
.
Set this variable to 1
to always get the Carp::longmess
output
of the warnings, instead of the regular carp
. This is the same
message you would get by doing:
- $tar->error(1);
Defaults to 0
.
Set this variable to 0
if you do not want any warnings printed.
Personally I recommend against doing this, but people asked for the
option. Also, be advised that this is of course not threadsafe.
Defaults to 1
.
Holds the last reported error. Kept for historical reasons, but its
use is very much discouraged. Use the error()
method instead:
- warn $tar->error unless $tar->extract;
Note that in older versions of this module, the error()
method
would return an effectively global value even when called an instance
method as above. This has since been fixed, and multiple instances of
Archive::Tar
now have separate error strings.
This variable indicates whether Archive::Tar
should allow
files to be extracted outside their current working directory.
Allowing this could have security implications, as a malicious tar archive could alter or replace any file the extracting user has permissions to. Therefor, the default is to not allow insecure extractions.
If you trust the archive, or have other reasons to allow the
archive to write files outside your current working directory,
set this variable to true
.
Note that this is a backwards incompatible change from version
1.36
and before.
This variable holds a boolean indicating if we currently have
perlio
support loaded. This will be enabled for any perl
greater than 5.8
compiled with perlio
.
If you feel strongly about disabling it, set this variable to
false
. Note that you will then need IO::String
installed
to support writing stringified archives.
Don't change this variable unless you really know what you're doing.
This variable holds a boolean indicating if we currently have
IO::String
support loaded. This will be enabled for any perl
that has a loadable IO::String
module.
If you feel strongly about disabling it, set this variable to
false
. Note that you will then need perlio
support from
your perl to be able to write stringified archives.
Don't change this variable unless you really know what you're doing.
This variable holds a boolean indicating if we will create
zero padded numbers for size
, mtime
and checksum
.
The default is 0
, indicating that we will create space padded
numbers. Added for compatibility with busybox
implementations.
You will need perl version 5.005_03 or newer.
Yes it is. It's pure perl, so it's a lot slower then your /bin/tar
However, it's very portable. If speed is an issue, consider using
/bin/tar instead.
Yes it is, see previous answer. Since Compress::Zlib
and therefore
IO::Zlib
doesn't support seek on their filehandles, there is little
choice but to read the archive into memory.
This is ok if you want to do in-memory manipulation of the archive.
If you just want to extract, use the extract_archive
class method
instead. It will optimize and write to disk immediately.
Another option is to use the iter
class method to iterate over
the files in the tarball without reading them all in memory at once.
In some cases, yes. You can use the iter
class method to iterate
over the files in the tarball without reading them all in memory at once.
Probably more than X kb, since it will all be read into memory. If
this is a problem, and you don't need to do in memory manipulation
of the archive, consider using the iter
class method, or /bin/tar
instead.
Unix
has a few filetypes that aren't supported on other platforms,
like Win32
. If we encounter a hardlink
or symlink we'll just
try to make a copy of the original file, rather than throwing an error.
This does require you to read the entire archive in to memory first,
since otherwise we wouldn't know what data to fill the copy with.
(This means that you cannot use the class methods, including iter
on archives that have incompatible filetypes and still expect things
to work).
For other filetypes, like chardevs
and blockdevs
we'll warn that
the extraction of this particular item didn't work.
By default, Archive::Tar
is in a completely POSIX-compatible
mode, which uses the POSIX-specification of tar
to store files.
For paths greater than 100 characters, this is done using the
POSIX header prefix
. Non-POSIX-compatible clients may not support
this part of the specification, and may only support the GNU Extended
Header
functionality. To facilitate those clients, you can set the
$Archive::Tar::DO_NOT_USE_PREFIX
variable to true
. See the
GLOBAL VARIABLES
section for details on this variable.
Note that GNU tar earlier than version 1.14 does not cope well with
the POSIX header prefix
. If you use such a version, consider setting
the $Archive::Tar::DO_NOT_USE_PREFIX
variable to true
.
Sometimes, you might not wish to extract a complete archive, just the files that are relevant to you, based on some criteria.
You can do this by filtering a list of Archive::Tar::File
objects
based on your criteria. For example, to extract only files that have
the string foo
in their title, you would use:
- $tar->extract(
- grep { $_->full_path =~ /foo/ } $tar->get_files
- );
This way, you can filter on any attribute of the files in the archive.
Consult the Archive::Tar::File
documentation on how to use these
objects.
The Archive::Tar
module can optionally use Compress::Zlib
(via
the IO::Zlib
module) to access tar files that have been compressed
with gzip
. Unfortunately tar files compressed with the Unix compress
utility cannot be read by Compress::Zlib
and so cannot be directly
accesses by Archive::Tar
.
If the uncompress
or gunzip
programs are available, you can use
one of these workarounds to read .tar.Z files from Archive::Tar
Firstly with uncompress
and this with gunzip
Similarly, if the compress
program is available, you can use this to
write a .tar.Z file
Archive::Tar
uses byte semantics for any files it reads from or writes
to disk. This is not a problem if you only deal with files and never
look at their content or work solely with byte strings. But if you use
Unicode strings with character semantics, some additional steps need
to be taken.
For example, if you add a Unicode string like
- # Problem
- $tar->add_data('file.txt', "Euro: \x{20AC}");
then there will be a problem later when the tarfile gets written out
to disk via $tar-
write()>:
- Wide character in print at .../Archive/Tar.pm line 1014.
The data was added as a Unicode string and when writing it out to disk,
the :utf8
line discipline wasn't set by Archive::Tar
, so Perl
tried to convert the string to ISO-8859 and failed. The written file
now contains garbage.
For this reason, Unicode strings need to be converted to UTF-8-encoded
bytestrings before they are handed off to add_data()
:
A opposite problem occurs if you extract a UTF8-encoded file from a
tarball. Using get_content()
on the Archive::Tar::File
object
will return its content as a bytestring, not as a Unicode string.
If you want it to be a Unicode string (because you want character semantics with operations like regular expression matching), you need to decode the UTF8-encoded content and have Perl convert it into a Unicode string:
There is no easy way to provide this functionality in Archive::Tar
,
because a tarball can contain many files, and each of which could be
encoded in a different way.
The AIX tar does not fill all unused space in the tar archive with 0x00.
This sometimes leads to warning messages from Archive::Tar
.
- Invalid header block at offset nnn
A fix for that problem is scheduled to be released in the following levels of AIX, all of which should be coming out in the 4th quarter of 2009:
- AIX 5.3 TL7 SP10
- AIX 5.3 TL8 SP8
- AIX 5.3 TL9 SP5
- AIX 5.3 TL10 SP2
- AIX 6.1 TL0 SP11
- AIX 6.1 TL1 SP7
- AIX 6.1 TL2 SP6
- AIX 6.1 TL3 SP3
The IBM APAR number for this problem is IZ50240 (Reported component ID: 5765G0300 / AIX 5.3). It is possible to get an ifix for that problem. If you need an ifix please contact your local IBM AIX support.
Currently I don't know of any portable pure perl way to do this. Suggestions welcome.
Currently, we only allow opened filehandles or filenames, but not strings. The internals would need some reworking to facilitate stringified archives.
Currently, we only support this if the filehandle is an IO::Zlib object. Environments, like apache, will present you with an opened filehandle to an uploaded file, which might be a compressed archive.
The specification which tar derives from; http://www.opengroup.org/onlinepubs/007904975/utilities/pax.html
http://www.delorie.com/gnu/docs/tar/tar_114.html
GNU Tar authors have expressed their intention to become completely
POSIX-compatible; http://www.gnu.org/software/tar/manual/html_node/Formats.html
Lists known issues and incompatibilities; http://gd.tuwien.ac.at/utils/archivers/star/README.otherbugs
This module by Jos Boumans <kane@cpan.org>.
Please reports bugs to <bug-archive-tar@rt.cpan.org>.
Thanks to Sean Burke, Chris Nandor, Chip Salzenberg, Tim Heaney, Gisle Aas, Rainer Tammer and especially Andrew Savige for their help and suggestions.
This module is copyright (c) 2002 - 2009 Jos Boumans <kane@cpan.org>. All rights reserved.
This library is free software; you may redistribute and/or modify it under the same terms as Perl itself.