Paul Marquess > Compress-Zlib-2.015 > Compress::Zlib::FAQ

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NAME ^

Compress::Zlib::FAQ -- Frequently Asked Questions about Compress::Zlib

DESCRIPTION ^

Common questions answered.

Compatibility with Unix compress/uncompress.

Although Compress::Zlib has a pair of functions called compress and uncompress, they are not related to the Unix programs of the same name. The Compress::Zlib module is not compatible with Unix compress.

If you have the uncompress program available, you can use this to read compressed files

    open F, "uncompress -c $filename |";
    while (<F>)
    {
        ...

Alternatively, if you have the gunzip program available, you can use this to read compressed files

    open F, "gunzip -c $filename |";
    while (<F>)
    {
        ...

and this to write compress files, if you have the compress program available

    open F, "| compress -c $filename ";
    print F "data";
    ...
    close F ;

Accessing .tar.Z files

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 accessed 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

    use strict;
    use warnings;
    use Archive::Tar;

    open F, "uncompress -c $filename |";
    my $tar = Archive::Tar->new(*F);
    ...

and this with gunzip

    use strict;
    use warnings;
    use Archive::Tar;

    open F, "gunzip -c $filename |";
    my $tar = Archive::Tar->new(*F);
    ...

Similarly, if the compress program is available, you can use this to write a .tar.Z file

    use strict;
    use warnings;
    use Archive::Tar;
    use IO::File;

    my $fh = new IO::File "| compress -c >$filename";
    my $tar = Archive::Tar->new();
    ...
    $tar->write($fh);
    $fh->close ;

Accessing Zip Files

This module does not support reading/writing zip files.

Support for reading/writing zip files is included with the IO::Compress::Zip and IO::Uncompress::Unzip modules.

The primary focus of the IO::Compress::Zip and IO::Uncompress::Unzip modules is to provide an IO::File compatible streaming read/write interface to zip files/buffers. They are not fully flegged archivers. If you are looking for an archiver check out the Archive::Zip module. You can find it on CPAN at

    http://www.cpan.org/modules/by-module/Archive/Archive-Zip-*.tar.gz    

SEE ALSO ^

Compress::Zlib, IO::Compress::Gzip, IO::Uncompress::Gunzip, IO::Compress::Deflate, IO::Uncompress::Inflate, IO::Compress::RawDeflate, IO::Uncompress::RawInflate, IO::Compress::Bzip2, IO::Uncompress::Bunzip2, IO::Compress::Lzop, IO::Uncompress::UnLzop, IO::Compress::Lzf, IO::Uncompress::UnLzf, IO::Uncompress::AnyInflate, IO::Uncompress::AnyUncompress

Compress::Zlib::FAQ

File::GlobMapper, Archive::Zip, Archive::Tar, IO::Zlib

AUTHOR ^

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

MODIFICATION HISTORY ^

See the Changes file.

COPYRIGHT AND LICENSE ^

Copyright (c) 2005-2008 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.

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