Question

The situtation:

I received a big rar file containing multiple log files.
I am converting each individual log file to a bzip2 archive.

What i am doing now:

Decompress the rar file completly, and only then convert all log files to bzip2 archives.

What i would like to do:

Be as efficient as possible by not storing all the uncompressed files first.

My first idea is to parse the output of unrar to distinguish when a file has been fully uncompressed, and then start a bzip2 compression on it.

How could i do that?

Answer 1

Since unrar supports a p command to print files, something like this should work:

for FN in $(unrar lb "$RARFILE"); do
   unrar p -ierr "$RARFILE" "$FN" | bzip2 -c > "$FN.bz2"
done

If the archive is a “solid” archive this will not be very efficient since it will have to process all the files multiple times. Also be careful if your file names can contain spaces.