[X-Unix] How to *quietly* unarchive a .bz2 file?

[John Baltutis]

On 10/3/10, Jerry Krinock <jerry at ieee.org> wrote:
>
> For remote diagnosis of problems, I have a script which unarchives .bz2
>system logs, filters them for certain keywords, and zips the resulting text
>into an archive which the user can email to me.
>
> This works except that for unarchiving the .bz2 logs, I use /usr/bin/open,
>which launches the Archive Utility app, which opens a Finder window that
>activates for each .bz2 file, creating visual pollution and intercepting any
>keystrokes which the user might be typing in another app.  Very annoying.
>
> Archive Utility.app is in /System/Library/CoreServices and has no
>documentation.
>
> It appears that on Linux, people use 'bunzip' or 'tar -x' for this.  Well,
>bunzip seems to not exist on Mac OS X, and although 'man tar' says that "this
>implementation recognizes bzip2 compression automatically when reading
>archives", it doesn't work on a .bz2?
>
> JerryMacMini:~ jk$ tar -x -f /var/log/system.log.0.bz2
> tar: This does not look like a tar archive
> tar: Skipping to next header
> tar: Archive contains obsolescent base-64 headers
> tar: Error exit delayed from previous errors
>
> I get the same problem if I use the -j option (which, according to 'man tar',
>is not necessary for extracting)
>
> JerryMacMini:~ jk$ tar -x -j -f /var/log/system.log.0.bz2
> tar: This does not look like a tar archive
> tar: Skipping to next header
> tar: Archive contains obsolescent base-64 headers
> tar: Error exit delayed from previous errors
>
> How can I quietly unarchive a .bz2 file?

Why go through all of that? Just e-mail the .bz2 logs to yourself and open them
in Console. Then, you can do the filtering on your machine.