Tarball with links

xeon123 · 02-28-2007, 04:36 AM

1 - Suppose that i've a directory that has several symbolic links that points to different places of the filesystem. If i want to do a tarball to the respective directory, how do i set the option to also include in the tarball the filesystem structure where the links points to?

2 - The same question, but, for hard link?

Thanks,
Pedro

colucix · 02-28-2007, 07:10 AM

In the GNU version of tar it is done by default (no options needed). The soft links are preserved, even if the file they link to has been removed (in this case you get a broken link). On the other hand, there is an option to dereference links:

Quote:

-h, --dereference
don’t dump symlinks; dump the files they point to

The hard links are copied as is.

This all is not true for the UNIX version of tar!

xeon123 · 02-28-2007, 07:20 AM

I think, i don't understand your answer.

If i've the a link, let's call "ln_test" in /home/user/ directory, that points to /opt/test.txt. If i do, tar -cvf zipped.tar ln_test, i want that /opt/test.txt also be included in the tarball, together with the link.

Is this possible.

xeon123 · 02-28-2007, 07:21 AM

I forgot to put the question:

Is this possible?

colucix · 02-28-2007, 07:32 AM

Quote:

Originally Posted by pedrosacosta

If i do, tar -cvf zipped.tar ln_test, i want that /opt/test.txt also be included in the tarball, together with the link

I think I did not understood the problem!

I am afraid it is not possible. Indeed, to spread some files all over the system is a task for a kind of installer.

colucix · 02-28-2007, 07:41 AM

Sorry, my previous post was not really true, in the sense you can do something like

Code:

tar cvf file.tar dir_one dir_two

to archive multiple directory in one tarball. Anyway, I think there is no option to automatically follow links to include the files they point to (with their absolute path, I mean). Furthermore you will face another problem: in absolute paths (those beginning with /) the leading / is stripped out to minimize the risk of overwriting system files!

exvor · 02-28-2007, 08:34 AM

Dereferencing the links makes the pointed to location copied to the tar file as well. Thats what I got from the statement above.

Quote:

In the GNU version of tar it is done by default (no options needed). The soft links are preserved, even if the file they link to has been removed (in this case you get a broken link). On the other hand, there is an option to dereference links:

Quote:

-h, --dereference
don’t dump symlinks; dump the files they point to
The hard links are copied as is.

This all is not true for the UNIX version of tar!

colucix · 02-28-2007, 09:01 AM

Yes, but not in the way the OP expected! Option -h copies the file in place of the link, assigning the name of the link itself to the copied file. For example, if I have the following link

Code:

my_link -> /usr/local/testfile.txt

The file testfile.txt will be copied into the archive in place of the symbolic link and will be named my_link (the path and name of the file the link pointed to, will be lost).