Re: How to do a survey on lbzip2 as a bzip2 alternative?

[Nicolas Alvarez <nicolas.alvarez@gmail.com>]

ERSEK Laszlo wrote:
> A trivial reason to use bzip2 is to decompress a file downloaded from the
> internet. If you have a multi-core CPU and the file was compressed with
> standard bzip2, you might want to use lbzip2. Perhaps even automatically.

If you download and decompress with bzip2, it takes download_time + 
bzip2_time. If you download and decompress with lbzip2, it takes 
download_time + bzip2_time/ncores.

Decompressing concurrently with the download is faster than both: it takes a 
total of max(download_time,bzip2_time). The download is usually the slowest, 
so we can just say it takes download_time.

Here's one way:

curl http://example.com/file.tar.bz2 | tee file.tar.bz2 | bunzip2 > file.tar

My usual command is actually this:

~/src$ curl http://example.com/file.tar.bz2 | tee ~/downloads/file.tar.bz2 | 
tar xjv

-- 
Nicolas

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