1. The option --xz or -J (see below) is used.
2. The xz binary is set as compressor using --use-compress-program option.
3. The file name of the archive being created ends in `.xz' and
auto-compress option (-a) is used.
1. The option --xz or -J (see below) is used.
2. The xz binary is set as compressor using --use-compress-program option.
3. The file name of the archive being created ends in `.xz' and
auto-compress option (-a) is used.