man Dpkg::Compression (3): simple database of available compression methods

DESCRIPTION

This modules provides a few public functions and a public regex to interact with the set of supported compression methods.

FUNCTIONS

@list = compression_get_list(): Returns a list of supported compression methods (sorted alphabetically).
compression_is_supported($comp): Returns a boolean indicating whether the give compression method is known and supported.
compression_get_property($comp, $property): Returns the requested property of the compression method. Returns undef if either the property or the compression method doesn't exist. Valid properties currently include ``file_ext'' for the file extension, ``default_level'' for the default compression level, ``comp_prog'' for the name of the compression program and ``decomp_prog'' for the name of the decompression program.
compression_guess_from_filename($filename): Returns the compression method that is likely used on the indicated filename based on its file extension.
$regex = compression_get_file_extension_regex(): Returns a regex that matches a file extension of a file compressed with one of the supported compression methods.
$comp = compression_get_default(): Return the default compression method. It is ``xz'' unless "compression_set_default" has been used to change it.
compression_set_default($comp): Change the default compression method. Errors out if the given compression method is not supported.
$level = compression_get_default_level(): Return the default compression level used when compressing data. It's ``9'' for ``gzip'' and ``bzip2'', ``6'' for ``xz'' and ``lzma'', unless "compression_set_default_level" has been used to change it.
compression_set_default_level($level): Change the default compression level. Passing undef as the level will reset it to the compressor specific default, otherwise errors out if the level is not valid (see "compression_is_valid_level").
compression_is_valid_level($level): Returns a boolean indicating whether $level is a valid compression level (it must be either a number between 1 and 9 or ``fast'' or ``best'')

CHANGES

Version 1.02 (dpkg 1.17.2)

New function: compression_get_file_extension_regex()

Deprecated variables: $default_compression, $default_compression_level and $compression_re_file_ext

Version 1.01 (dpkg 1.16.1)

Default compression level is not global any more, it is per compressor type.

Version 1.00 (dpkg 1.15.6)