I want to use tar to preserve only file names, file contents, and the executable bit for the owner (and ignore the executable bit for group and other). The command I have come up with is
tar -cf <name>.tar --numeric-owner --owner=0 --group=0 --mode="go-rwx,u-rw" <files>
I would like the output <name>.tar not to change unless I change the file name, file contents, or owner's executable bit in one or more of <files>. Assume that the <files> are in sorted order by name.
Will the command that I have written do that?
Related
I have a container that I want to export as a .tar file. I have used a podman run with a tar --exclude=/dir1 --exclude=/dir2 … that outputs to a file located on a bind-mounted host dir. But recently this has been giving me some tar: .: file changed as we read it errors, which podman/docker export would avoid. Besides the export I suppose is more efficient. So I'm trying to migrate to using the export, but the major obstacle is I can't seem to find a way to exclude paths from the tar stream.
If possible, I'd like to avoid modifying a tar archive already saved on disk, and instead modify the stream before it gets saved to a file.
I've been banging my head for multiple hours, trying useless advices from ChatGPT, looking at cpio, and attempting to pipe the podman export to tar --exclude … command. With the last I did have small success at some point, but couldn't make tar save the result to a particularly named file.
Any suggestions?
(note: I do not make distinction between docker and podman here as their export command is completely the same, and it's useful for searchability)
The man page for tar uses the word "dump" and its forms several times. What does it mean? For example (manual page for tar 1.26):
"-h, --dereferencefollow symlinks; archive and dump the files they point to"
Many popular systems have a "trash can" or "recycle bin." I don't want the files dumped there, but it kind of sounds that way.
At present, I don't want tar to write or delete any file, except that I want tar to create or update a single tarball.
FYI, the man page for the tar installed on the system I am using at the moment is a lot shorter than what appears to be the current version. And the description of -h, --dereference there seems very different to me:
"When reading or writing a file to be archived, tar accesses the file that a symbolic link points to, rather than the symlink itself. See section Symbolic Links."
P.S. I could not get "block quote" to work properly in this post.
File system backups are also called dumps.
—#raymond-chen, quoting GNU tar manual
A docker add will nicely extract the supplied compressed file into the directory specified in the zip/tar file
How can I extract it into a different directory?
Eg. if the file extracts to /myfile but I would prefer /otherFile
Don't believe there's any way to do this just using the ADD instruction. ADD supports a target directory obviously, like ADD ["<src>", "<dest>"] however it's still going to extract into the dir you have in the tar within that.
2 options, either rename the dir in the tar or do a RUN mv myfile otherfile after adding.
Is there a specific reason you need it to be named something in particular?
Think about this scenario where you build a tomcat image,
ADD apache-tomcat-8.0.48.tar.gz /opt
This cmd will extract the tar to /opt/apache-tomcat-8.0.48 , if you don't like the long folder name(apache-tomcat-8.0.48) then the requirement happens.
On server A, I created a tar file (backup.tar.gz) of the entire website /www. The tar file includes the top-level directory www
On server B, I want to put those files into /public_html but not include the top level directory www
Of course, tar -xzif backup.tar.gz places everything into /public_html/www
How do I do this?
Thanks!
You can use the --transform option to change the beginning of the archived file names to something else. As an example, in my case I had installed owncloud in directory named sscloud instead of owncloud. This caused problems when upgrading from the *.tar file. So I used the transform option like so:
tar xvf owncloud-10.3.2.tar.bz2 --transform='s/owncloud/sscloud/' --overwrite
The transform option takes sed-like commands. The above will replace the first occurrence of owncloud with sscloud.
Answer is:
tar --strip-components 1 -xvf backup.tar.gz
I kind of found the answer on the stackoverflow but have some confusion. I need some help.
I have a tar file which contains files and folders like this: usr/CCS/HMS*
I would like to extract all files and folders usr/CCS/HMS* but into a different filesystem, the new filesystem is /usr/TRAINP
HMS* should replace TRAINP*. TRAINP has folders like TRAINP/TRAINP.GL, TRAINP.AR, etc
the backup contains folders like usr/CCS/HMS/HMS.GL, usr/CCS/HMS.AR
When I am doing, it is restoring under /usr/TRAINP. I want usr/CCS/HMS* to replace /usr/TRAINP. This is kind of database restore with a different name.
Thanks a lot in advance.
Tar itself does not rename the contents when extracting. The best bet is to extract to some place in the target filesystem and move the results where you want.
For example:
cd /usr/CCS/TRAINP1
tar xf archive.tar usr/CCS/HMS1
mv usr/CCS/HMS1/* .
Or, if the TRAINP directories do not exist:
cd /
tar xf archive.tar usr/CCS
cd usr/CCS
for file in HMS*; do mv "$file" "TRAINP${file#HMS}"; done
Of course there are many variations and alternatives that will yield the same result. Note my example assumes usr/CCS belongs in /usr/CCS.