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📛 NAME

Compress::Raw::Bzip2 - Low-Level Interface to bzip2 compression library

🚀 Quick Reference

Use Case	Command	Description
🔧 Create compression object	new Compress::Raw::Bzip2 [OPTS]	Returns compression object and status
🗜️ Compress data	$bz->bzdeflate($input, $output)	Compress input to output
💨 Flush compressed data	$bz->bzflush($output)	Flush pending compressed data
🔚 Close compression stream	$bz->bzclose($output)	Terminate and flush all data
🔽 Create decompression object	new Compress::Raw::Bunzip2 [OPTS]	Returns decompression object and status
📂 Decompress data	$bz->bzinflate($input, $output)	Uncompress input to output
📋 Get library version	Compress::Raw::Bzip2::bzlibversion()	Returns bzip2 library version string

📋 SYNOPSIS

use Compress::Raw::Bzip2;

my ($bz, $status) = new Compress::Raw::Bzip2 [OPTS]
    or die "Cannot create bzip2 object: $bzerno\n";

$status = $bz->bzdeflate($input, $output);
$status = $bz->bzflush($output);
$status = $bz->bzclose($output);

my ($bz, $status) = new Compress::Raw::Bunzip2 [OPTS]
    or die "Cannot create bunzip2 object: $bzerno\n";

$status = $bz->bzinflate($input, $output);

my $version = Compress::Raw::Bzip2::bzlibversion();

📖 DESCRIPTION

Provides an interface to the in-memory compression/uncompression functions from the bzip2 compression library.

Although the primary purpose for the existence of Compress::Raw::Bzip2 is for use by the IO::Compress::Bzip2 and IO::Compress::Bunzip2 modules, it can be used on its own for simple compression/uncompression tasks.

🗜️ Compression

($z, $status) = new Compress::Raw::Bzip2 $appendOutput, $blockSize100k, $workfactor;

Creates a new compression object.

If successful, returns the initialised compression object $z and a $status of BZ_OK in a list context. In scalar context it returns the deflation object $z only.

If not successful, the returned compression object $z will be undef and $status will hold a bzip2 error code.

Below is a list of the valid options:

• $appendOutput — Controls whether the compressed data is appended to the output buffer in the bzdeflate, bzflush and bzclose methods. Defaults to 1.
• $blockSize100k — Specifies the block size to be used for compression. Value between 1 and 9 inclusive; actual block size is 100000 x this figure. 9 gives the best compression but takes most memory. Defaults to 1.
• $workfactor — Controls how the compression phase behaves with worst-case, highly repetitive input data. Lower values reduce effort before resorting to a slower fallback algorithm. Allowable values 0 to 250; 0 is equivalent to default 30. Defaults to 0.

$status = $bz->bzdeflate($input, $output);

Reads the contents of $input, compresses it and writes the compressed data to $output.

Returns BZ_RUN_OK on success and a bzip2 error code on failure.

If appendOutput is enabled in the constructor, the compressed data will be appended to $output. If not enabled, $output will be truncated before the compressed data is written to it.

$status = $bz->bzflush($output);

Flushes any pending compressed data to $output.

Returns BZ_RUN_OK on success and a bzip2 error code on failure.

$status = $bz->bzclose($output);

Terminates the compressed data stream and flushes any pending compressed data to $output.

Returns BZ_STREAM_END on success and a bzip2 error code on failure.

📝 Example

No example provided in the original documentation.

🔽 Uncompression

($z, $status) = new Compress::Raw::Bunzip2 $appendOutput, $consumeInput, $small, $verbosity, $limitOutput;

Creates a new uncompression object.

If successful, returns the initialised uncompression object $z and a $status of BZ_OK in a list context. In scalar context it returns the deflation object $z only.

If not successful, the returned uncompression object $z will be undef and $status will hold a bzip2 error code.

Below is a list of the valid options:

• $appendOutput — Controls whether the uncompressed data is appended to the output buffer in the bzinflate, bzflush and bzclose methods. Defaults to 1.
• $consumeInput — (Option documented but no description given in original.)
• $small — If nonzero, the library will use an alternative decompression algorithm which uses less memory but at the cost of decompressing more slowly (roughly half the speed, maximum memory drops to around 2300k). Defaults to 0.
• $limitOutput — Limits the amount of memory used by the output buffer. When enabled, the size of the output buffer will be either 16k or the current allocation, whichever is larger. Also enables ConsumeInput. Defaults to false.
• $verbosity — This parameter is ignored. Defaults to 0.

$status = $z->bzinflate($input, $output);

Uncompresses $input and writes the uncompressed data to $output.

Returns BZ_OK if the uncompression was successful, but the end of the compressed data stream has not been reached. Returns BZ_STREAM_END on successful uncompression and the end of the compression stream has been reached.

If consumeInput is enabled in the constructor, $input will have all compressed data removed from it after uncompression. On BZ_OK return, $input will be an empty string; when BZ_STREAM_END, $input will either be empty or contain data immediately following the compressed stream.

If appendOutput is enabled, the uncompressed data will be appended to $output. If not enabled, $output will be truncated before the uncompressed data is written.

🔧 Misc

my $version = Compress::Raw::Bzip2::bzlibversion();

Returns the version of the underlying bzip2 library.

📊 Constants

The following bzip2 constants are exported by this module:

BZ_RUN
BZ_FLUSH
BZ_FINISH
BZ_OK
BZ_RUN_OK
BZ_FLUSH_OK
BZ_FINISH_OK
BZ_STREAM_END
BZ_SEQUENCE_ERROR
BZ_PARAM_ERROR
BZ_MEM_ERROR
BZ_DATA_ERROR
BZ_DATA_ERROR_MAGIC
BZ_IO_ERROR
BZ_UNEXPECTED_EOF
BZ_OUTBUFF_FULL
BZ_CONFIG_ERROR

📬 SUPPORT

General feedback/questions/bug reports should be sent to GitHub Issues (preferred) or RT CPAN.

👁️ 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::Lzma, IO::Uncompress::UnLzma, IO::Compress::Xz, IO::Uncompress::UnXz, IO::Compress::Lzip, IO::Uncompress::UnLzip, IO::Compress::Lzop, IO::Uncompress::UnLzop, IO::Compress::Lzf, IO::Uncompress::UnLzf, IO::Compress::Zstd, IO::Uncompress::UnZstd, IO::Uncompress::AnyInflate, IO::Uncompress::AnyUncompress

IO::Compress::FAQ

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

The primary site for the bzip2 program is https://sourceware.org/bzip2/.

See the module Compress::Bzip2.

✍️ AUTHOR

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

📜 MODIFICATION HISTORY

See the Changes file.

©️ COPYRIGHT AND LICENSE

Copyright (c) 2005-2021 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.

📛 NAME 🚀 Quick Reference 📋 SYNOPSIS 📖 DESCRIPTION 🗜️ Compression 🔽 Uncompression 🔧 Misc 📊 Constants 📬 SUPPORT 👁️ SEE ALSO ✍️ AUTHOR 📜 MODIFICATION HISTORY ©️ COPYRIGHT AND LICENSE