sage-uncompress-spkg

#!/usr/bin/env python

# USAGE:
#
#   sage-uncompress-spkg PKG [FILE]
#
# With a single argument, unpack the file PKG to the current directory.
#
# If FILE is specified, extract FILE from PKG and send it to
# stdout. (This option is present only for backwards compatibility:
# printing the SPKG.txt file from an old-style spkg.)

import sys
import tarfile
import zipfile

if __name__ == '__main__':
    filename = sys.argv[1]
    if tarfile.is_tarfile(filename):
        # tar file, possibly compressed:
        archive = tarfile.open(filename, 'r:*')
        if len(sys.argv) == 2:
            archive.extractall()
        else:
            member = sys.argv[2]
            if member in archive.getnames():
                SPKG_TXT = archive.extractfile(member)
                sys.stdout.write(SPKG_TXT.read())
                exit(1)
        archive.close()
        exit(0)
    if zipfile.is_zipfile(filename):
        # zip file:
        archive = zipfile.ZipFile(filename, 'r')
        if len(sys.argv) == 2:
            archive.extractall()
        else:
            member = sys.argv[2]
            if member in archive.namelist():
                sys.stdout.write(archive.read(member))
            else:
                exit(1)
        archive.close()
        exit(0)
    else:
        print ('Error: Unknown file type: {}'.format(filename))
        exit(1)