There has been some fuss generated by Jeff Atwood (who is a Windows developer, which is bad, and a Visual Basic one, which is worse), who seems, in my humble opinion, to be giving partial information around, as closed in his Windows-only world as he appears to be. In a recent article of his, Jeff makes a basic comparison between the ZIP and RAR compression systems. Unfortunately, most Windows people completely ignore that there’s something much better out there, that has been floating in the *nix world for quite a long time now. I’m talking about the powerful combination of tar and bzip2.
Let’s get to the facts right away. To experiment around, I’ve used a directory containing the source code of the Linux kernel, then I built that kernel, so that the size of the directory would be pretty big, and we would have both text files and binary files.
Here’s the size of the original directory:
$ du -sh /usr/src/linux-2.6.18.3 539M linux-2.6.18.3
This is what happens with ZIP:
$ time zip -r ~/linux /usr/src/linux-2.6.18.3 ... real 2m35.917s user 0m32.486s sys 0m6.024s $ ls -gGh ~/linux.zip -rw-r--r-- 1 141M 2007-02-24 01:04 /home/siovene/linux.zip
Fine, 141Mb in 2 minutes and 35 seconds. Let’s try RAR:
$ time ./rar_static a ~/linux.rar /usr/src/linux-2.6.18.3 ... real 5m8.715s user 2m14.012s sys 0m12.473s $ ls -gGh ~/linux.rar -lh -rw-r--r-- 1 132M 2007-02-24 01:26 /home/siovene/linux.rar
Ouch! Double time and just a slightly better compression! Let’s try TAR and BZIP2:
$ time tar cv linux-2.6.18.3 | bzip2 > ~/linux.tar.bz2 ... real 4m22.265s user 2m38.134s sys 0m5.608s $ ls -gGh ~/linux.tar.bz2 -rw-r--r-- 1 90M 2007-02-24 01:09 /home/siovene/linux.tar.bz2
Not too faster than RAR (but using two programs communicating through a pipe, so some overhead), but much more efficient! The compressed file is only 90Mb starting from an original uncompressed of 539Mb
Let’s summarize the data:
Method Time Size zip 2m35s 141Mb rar 5m08s 132Mb tar.bz2 4m22s 90Mb
In conclusion, you should use the best tools, interdependently from their popularity, and remember that there is so much more than what you can see from your Windows-user-perspective.
