Dpkg::Compression(3) libdpkg-perl Dpkg::Compression(3)NAME
Dpkg::Compression - simple database of available compression methods
DESCRIPTION
This modules provides a few public funcions and a public regex to interact with the set of supported compression methods.
EXPORTED VARIABLES
$compression_re_file_ext
A regex that matches a file extension of a file compressed with one of the supported compression methods.
EXPORTED FUNCTIONS
my @list = compression_get_list()
Returns a list of supported compression methods (sorted alphabetically).
compression_is_supported($comp)
Returns a boolean indicating whether the give compression method is known and supported.
compression_get_property($comp, $property)
Returns the requested property of the compression method. Returns undef if either the property or the compression method doesn't exist.
Valid properties currently include "file_ext" for the file extension, "comp_prog" for the name of the compression program and
"decomp_prog" for the name of the decompression program.
compression_guess_from_filename($filename)
Returns the compression method that is likely used on the indicated filename based on its file extension.
my $comp = compression_get_default()
Return the default compression method. It's "gzip" unless "compression_set_default" has been used to change it.
compression_set_default($comp)
Change the default compression method. Errors out if the given compression method is not supported.
my $level = compression_get_default_level()
Return the default compression level used when compressing data. It's "9" unless "compression_set_default_level" has been used to
change it.
compression_set_default_level($level)
Change the default compression level. Errors out if the level is not valid (see "compression_is_valid_level"). either a number between
1 and 9 or "fast" or "best".
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")
AUTHOR
Raphael Hertzog <hertzog@debian.org>.
1.16.0.3 2012-04-17 Dpkg::Compression(3)
Check Out this Related Man Page
AdvanceCOMP PNG Compression Utility(1) General Commands Manual AdvanceCOMP PNG Compression Utility(1)NAME
advpng - AdvanceCOMP PNG Compression Utility
SYNOPSIS
advpng [-l, --list] [-z, --recompress] [-0, --shrink-0]
[-1, --shrink-fast] [-2, --shrink-normal [-3, --shrink-extra]
[-4, --shrink-insane] [-f, --force] [-q, --quiet]
[-h, --help] [-V, --version] FILES...
DESCRIPTION
The main purpose of this utility is to recompress png files to get the smallest possible size.
Please note that this utility is not able to read a generic file. It's granted to be able to read only the files generated by the Advance-
MAME emulator.
To compress the files this utility uses the following strategies:
o Remove all ancillary chunks.
o Concatenate all the IDAT chunks.
o Use the 7zip Deflate implementation.
OPTIONS -l, --list FILES...
List the content of the specified files.
-z, --recompress FILES...
Recompress the specified files. If the -1, -2, -3 options are specified it's used the smallest file choice from the previous com-
pressed data and the new compression. If the -0 option is specified the file is always rewritten without any compression.
-0, --shrink-store
Disable the compression. The file is only stored and not compressed. The file is always rewritten also if it's bigger.
-1, --shrink-fast
Set the compression level to "fast".
-2, --shrink-normal
Set the compression level to "normal". This is the default level of compression.
-3, --shrink-extra
Set the compression level to "extra".
-4, --shrink-insane
Set the compression level to "insane".
-f, --force
Force the use of the new file also if it's bigger.
COPYRIGHT
This file is Copyright (C) 2002 Andrea Mazzoleni, Filipe Estima
SEE ALSO advzip(1), advmng(1), advdef(1)
AdvanceCOMP PNG Compression Utility(1)