Decompress a .bz2 file
nbdkit file
--filter=bzip2
FILENAME.bz2
"nbdkit-bzip2-filter" is a filter for nbdkit(1) which transparently decompresses a bzip2-compressed file. You can place this filter on top of nbdkit-file-plugin(1) to decompress a local .bz2 file.
The filter only allows read-only connections.
Note that bzip2 files are not very good for random access in large files because seeking to a position in the bzip2 file involves decompressing all data before that point in the file. A more practical method to compress large disk images is to use xz(1) or plzip(1). Both nbdkit-xz-filter(1) and nbdkit-lzip-filter(1) support block-level decompression if the file was compressed using the right options.
To allow seeking this filter has to keep the contents of the complete uncompressed file, which it does in a hidden temporary file under $TMPDIR.
There are no parameters specific to this filter.
"TMPDIR"
Because the bzip2 format is not seekable, this filter has to store the complete contents of the compressed file in a temporary file located in /var/tmp by default. You can override this location by setting the "TMPDIR" environment variable before starting nbdkit.
$filterdir/nbdkit-bzip2-filter.so
The plugin.
Use "nbdkit --dump-config" to find the location of $filterdir.
"nbdkit-bzip2-filter" first appeared in nbdkit 1.40. It is derived from the "nbdkit-gzip-filter" which first appeared in nbdkit 1.22.