ExtractAr

A basic Python implementation of the Unix ar command which can extract files from a Debian binary package archive.

ExtractAr is a rework of the unix_ar single Python module library by remram44 but no longer supported and maintained. It is still a single module library, but with half the content; ExtractAr, meaning "Extract Archive" only reads and extracts files archived, not creating archives.

As Python is cross-platform, making use of the standard library, it means archive files can be extracted on Windows or Linux systems.

Usage

The below code snippet is a basic example of how to use ExtractAr:

import extractar 

if __name__ == "__main__":
    ar = extractar.Archive("/path/to/deb/file.deb")
    ar.open() # load the archive into memory
    
    print("Extracting content from archive...")
    ar.extractall()
    
    print("Archive extracted.")

However, ExtractAr employs strict handling of content through many stages of the reading and extraction process. It's possible that an I/O error occurs when dealing with reading the archive file. When extracting files, it's possible that the archive content is corrupt or not in the Debian binary package format. The following is a more robust method of operating with ExtractAr:

import extractar 
import sys

if __name__ == "__main__":
    ar = extractar.Archive("/path/to/deb/file.deb")

    try:
        ar.open() # load the archive into memory
    except:
        print("There was an issue when reading the archive file:", sys.exc_info()[0])
    
    print("Extracting content from archive...")

    try:
        ar.extractall()
    except extractar.ArchiveMagicByteError:
        print("Looks like the archive isn't of Debian binary package format.")
    except extractar.ArchiveBufferReadError as err:
        print("The archive might be corrupt. The following was raised when extracting files:", err)
    except:
        print("An issue occurred during archive extraction:", sys.exc_info()[0])
    
    print("Archive extracted.")

Code may not be required specific handling in this manner, but is an example of dealing with exceptions that may arise during the runtime of the file.

Licence

The original source code was licence under Modified BSD licence, which has been acknowledged appropriately. For licence agreement on ExtractAr, see LICENCE.txt for licence agreement.