Tar a directory, but don't store full absolute paths in the archive

Question

I have the following command in the part of a backup shell script:

tar -cjf site1.bz2 /var/www/site1/ 

When I list the contents of the archive, I get:

tar -tf site1.bz2 var/www/site1/style.css var/www/site1/index.html var/www/site1/page2.html var/www/site1/page3.html var/www/site1/images/img1.png var/www/site1/images/img2.png var/www/site1/subdir/index.html 

But I would like to remove the part /var/www/site1 from directory and file names within the archive, in order to simplify extraction and avoid useless constant directory structure. Never know, in case I would extract backuped websites in a place where web data weren't stored under /var/www.

For the example above, I would like to have :

tar -tf site1.bz2 style.css index.html page2.html page3.html images/img1.png images/img2.png subdir/index.html 

So, that when I extract, files are extracted in the current directory and I don't need to move extracted files afterwards, and so that sub-directory structures is preserved.

There are already many questions about tar and backuping in stackoverflow and at other places on the web, but most of them ask for dropping the entire sub-directory structure (flattening), or just add or remove the initial / in the names (I don't know what it changes exactly when extracting), but no more.

After having read some of the solutions found here and there as well as the manual, I tried :

tar -cjf site1.bz2 -C . /var/www/site1/ tar -cjf site1.bz2 -C / /var/www/site1/ tar -cjf site1.bz2 -C /var/www/site1/ /var/www/site1/ tar -cjf site1.bz2 --strip-components=3 /var/www/site1/ 

But none of them worked the way I want. Some do nothing, some others don't archive sub-directories anymore.

It's inside a backup shell script launched by a Cron, so I don't know well, which user runs it, what is the path and the current directory, so always writing absolute path is required for everything, and would prefer not changing current directory to avoid breaking something further in the script (because it doesn't only backup websites, but also databases, then send all that to FTP etc.)

How to achieve this?

Have I just misunderstood how the option -C works?

Answer 1

tar -cjf site1.tar.bz2 -C /var/www/site1 . 

In the above example, tar will change to directory /var/www/site1 before doing its thing because the option -C /var/www/site1 was given.

From man tar:

OTHER OPTIONS    -C, --directory DIR        change to directory DIR 

Answer 2

The option -C works; just for clarification I'll post 2 examples:

1. creation of a tarball without the full path: full path /home/testuser/workspace/project/application.war and what we want is just project/application.war so:

   tar -cvf output_filename.tar  -C /home/testuser/workspace project 

   Note: there is a space between workspace and project; tar will replace full path with just project .

2. extraction of tarball with changing the target path (default to ., i.e current directory)

   tar -xvf output_filename.tar -C /home/deploy/ 

   tar will extract tarball based on given path and preserving the creation path; in our example the file application.war will be extracted to /home/deploy/project/application.war.

   /home/deploy: given on extract
   project: given on creation of tarball

Note : if you want to place the created tarball in a target directory, you just add the target path before tarball name. e.g.:

tar -cvf /path/to/place/output_filename.tar  -C /home/testuser/workspace project