info > Dpkg::Compression

man perldoc info pydoc3 ri search

📛 NAME

Dpkg::Compression — simple database of available compression methods

🚀 Quick Reference

Use Case	Command	Description
List all supported compression methods	compression_get_list()	Sorted alphabetically
Check if a compression method is supported	compression_is_supported($comp)	Returns a boolean
Get a property of a compression method	compression_get_property($comp, $property)	file_ext, default_level, comp_prog, decomp_prog
Guess compression method from filename	compression_guess_from_filename($filename)	Based on file extension
Regex to match compressed file extensions	compression_get_file_extension_regex()	Regex for all supported extensions
Get default compression method	compression_get_default()	Usually "xz"
Set default compression method	compression_set_default($comp)	Errors if not supported
Get default compression level	compression_get_default_level()	Compressor‑specific default
Set default compression level	compression_set_default_level($level)	Level number, "fast" or "best"
Validate a compression level	compression_is_valid_level($level)	Boolean, range 1‑9 or "fast" / "best"

📖 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 2.00 (dpkg 1.20.0)

Hide variables: $default_compression, $default_compression_level and $compression_re_file_ext.

🔄 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)

Mark the module as public.

1.21.1 — 2025‑09‑09 — Dpkg::Compression(3perl)

📛 NAME 🚀 Quick Reference 📖 DESCRIPTION ⚙️ FUNCTIONS 📝 CHANGES