Linux – bz2 file and “This does not look like a tar archive”

archivinglinuxtar

I've seen other questions related to this error (like Extracting a tar.gz file returns, “This does not look like a tar archive.”), but I'm not sure how to apply them to my problem:

First, download file:

$ wget --no-check-certificate https://wxpython.org/Phoenix/tools/doxygen-1.8.8-linux.bz2
--2017-04-06 15:06:11--  https://wxpython.org/Phoenix/tools/doxygen-1.8.8-linux.bz2
Resolving wxpython.org (wxpython.org)... 85.234.150.54
Connecting to wxpython.org (wxpython.org)|85.234.150.54|:443... connected.
HTTP request sent, awaiting response... 200 OK
Length: 3961996 (3.8M) [application/x-bzip2]
Saving to: ‘doxygen-1.8.8-linux.bz2’

100%[==============================================================================>] 3,961,996    734KB/s   in 5.0s   

2017-04-06 15:06:16 (778 KB/s) - ‘doxygen-1.8.8-linux.bz2’ saved [3961996/3961996]

Then, check file type of file:

$ file doxygen-1.8.8-linux.bz2 
doxygen-1.8.8-linux.bz2: bzip2 compressed data, block size = 900k

Well, it's "bzip2 compressed data", let's unpack it?:

$ tar xjvf doxygen-1.8.8-linux.bz2
tar: This does not look like a tar archive
tar: Skipping to next header
tar: Archive contains ‘\351\357\377I\211\304H\211’ where numeric mode_t value expected
tar: Archive contains ‘A\270\001\0\0\0H\211ǹ\001’ where numeric time_t value expected
tar: Archive contains ‘\307\350\216v)\0I\307’ where numeric uid_t value expected
tar: Archive contains ‘\004$P\254|\0\2770’ where numeric gid_t value expected
@\2678\350\330\351\357\377\2778
tar: @\2678\350\330\351\357\377\2778: Unknown file type '', extracted as normal file
tar: @�8������8: implausibly old time stamp 1970-01-01 00:59:59
tar: Skipping to next header
tar: Exiting with failure status due to previous errors

And I get an empty file unpacked:

$ ls -la @�8������8 
-rwxrwxr-x 1 user user 0 Jan  1  1970 @?8??????8

Strangely, if I use file-roller (Archive Manager) and unpack from the GUI, I do get a file unpacked:

$ ls -la ~/Desktop/doxygen-1.8.8-linux 
-rw-rw-r-- 1 user user 12283548 Apr  6 15:13 /home/user/Desktop/doxygen-1.8.8-linux
$ file ~/Desktop/doxygen-1.8.8-linux 
/home/user/Desktop/doxygen-1.8.8-linux: ELF 64-bit LSB  executable, x86-64, version 1 (GNU/Linux), dynamically linked (uses shared libs), for GNU/Linux 2.6.24, BuildID[sha1]=0eccee11d38322d5df3a1723651c2f18303e1188, not stripped

Ok, so what is going on here – why can't I unpack this from the command line, and how can I unpack this using the command line?

EDIT: actually I can unpack it with:

$ bzip2 -d doxygen-1.8.8-linux.bz2 
$ file doxygen-1.8.8-linux 
doxygen-1.8.8-linux: ELF 64-bit LSB  executable, x86-64, version 1 (GNU/Linux), dynamically linked (uses shared libs), for GNU/Linux 2.6.24, BuildID[sha1]=0eccee11d38322d5df3a1723651c2f18303e1188, not stripped

… so the only question remaining is – why couldn't I have used tar for this, as I had always otherwise done?

Best Answer

tar is just copying files together to one big .tar file without compression. bzip2, gzip, xz are file compressors for single files ie. tar files. The extension is .tar.gz, .tar.xz, .tar.bz2 or .tbz(2), .txz, .tgz etc.

tar can only handle .tar files with or without compression with bzip2, xz, gzip. but not non tar'ed .bz2, .xz archives.

Non tar'ed bzip files can be extracted with bzip2 -d file.bz2.

Related Solutions

Tar: This does not look like a tar archive

You have not compressed so do not name the target file somedir.tar.gz -- call it somedir.tar
- this is not really relevant to your problem -- tar xvf should have worked nevertheless
Recheck your transfer (specifically if over FTP) is a binary one (and not a text transfer)
Finally do check that the files have actually transferred correctly
- for this, you might check source and target side file sizes
- or even better, match their MD5 sums on both sides (this will check point 2 also)

If you've checked the above points and the MD5 sums match on both ends, you should first try to check your split. So, does the join and tar-tf work on the source machine?

If your somedir is very large, try the work-flow with a small directory.
Use tar cvpf to get a simple tarball first, split and test after a rejoin.
Now, copy the split to your target machine as before and test after a rejoin there.
This should speed up locating your problem.

Linux – Fix ‘This Does Not Look Like a Tar Archive’ Error

Looking at the error you are seeing coupled with the fact that you can indeed decompress it says that the file is a genuine TAR/Gzip archive, but perhaps not an immediate TAR is created after the Gzip.

Meaning, if you downloaded this from a web server, sometimes Gzip compression get’s applied to web content on the server level to speed up content download. But if not properly set on the server to ignore already compressed content such as this, it can inadvertently double-Gzip files.

With that in mind I would see if simply un-Gzip it from the command line to see what happens. Use a command like this:

gzip -d ldtp_3.5.0.orig.tar.gz

And see what the resulting file is. I have a funny feeling after you run that command, you will not see a ldtp_3.5.0.orig.tar in the directory but rather a file named like the source—ldtp_3.5.0.orig.tar.gz— but perhaps with modification changed? If that is the case it is truly double-Gzipped. So at this point—after that initial un-Gzip—you can run the tar command you have like this:

tar -xvzf ldtp_3.5.0.orig.tar.gz

And it should now properly decompress the full TAR archive.

Another way of doing something similar to that two step process is to pipe the output of gzip to tar like this:

gzip -dc ldtp_3.5.0.orig.tar.gz | tar -xvzf -

The c in the gzip as well as the - at the end of the command is the key:

The c option for gzip will tell gzip to decompress to the standard output stream.
The - at the end of the tar command means “use standard input.” So coupled with the the -c in gzip, the pipe will then take the standard output stream piped to it from gzip and connect that to standard input in tar.

Best Answer

Related Solutions

Tar: This does not look like a tar archive

Linux – Fix ‘This Does Not Look Like a Tar Archive’ Error

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