Extract part of tar file with absolute paths using 7zip - tar

I'm trying to extract files from a tar file on a windows 7 machine using 7Zip's 7za.exe the command line. The file is 700GB and I only need a specific subdirectory. This should be possible using the following command.
7za x -r test.zip folder\subfolder
Running this on a test file (test.zip) does what is expected, i.e. it extracts all (sub)files from the folder\subfolder in the zip file. However, for the tar file, it doesn't work. I think it is related to a difference in file listings, as exemplified below.
7za l test.zip
produces:
folder
folder\subfolder
folder\subfolder\on_ADJ.png
While
7za l 20150602.tar
produces (excerpt):
.\Corpus
.\Corpus\DOC
.\Corpus\DOC\manual.pdf
Parallel to the first command, I tried using the following command.
7za x -r 20150602.tar .\Corpus\DOC
However, it doesn't work. Working within quotes (".\Corpus\DOC") or without .\ doesn't work either and 7Zip produces the following error.
Cannot use absolute pathnames for this command
Am I right that the tar file has absolute paths in it? If so, how could I solve this problem without having to extract the whole file?

Related

Exclude a directory from `podman/docker export` stream and save to a file

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)

Error using the 'find' command to generate a collection file on opencv

I am facing a problem generating a collection file of the positive images to train the Haar Cascade in OpenCV to detect a car. On every tutorial I found on the internet, it is the same command, however i am unable to execute it.
I am using Command Prompt and Windows Power Shell to execute this command. find ./positive_images/ -iname '.*pgm' > positives.txt the screenshot of the output I am running this command from root of my directory. The positive images are stored in positive_images folder.
OUTPUT:
File not found - '*pgm'
However, the positive_images directory contains 550 files with .pgm extension.
Error File not found - '*pgm'
I am using Command Prompt and Windows Power Shell to execute this command:
find ./positive_images/ -iname '.*pgm' > positives.txt
The above command is using the syntax of a Unix version of find, but you are running it under Windows. PowerShell does not have a built in find command so you are running C:\Windows\System32\find.exe.
Notes:
Unix find is used to search for files.
Windows find is used to search for string in files.
As you are running on Windows you need to use dir instead of find:
dir /b /s positive_images\*.pgm > positives.txt
Further Reading
An A-Z Index of the Windows CMD command line - An excellent reference for all things Windows cmd line related.
dir - Display a list of files and subfolders.
find - Search for a text string in a file & display all the lines where it is found.

docker add extract to custom directory

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.

How do I extract a TAR to a different destination directory

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

Tar Error [can not open: not a directory]

I have made some archive file with the tar gnome GUI on Ubuntu but when I try to extract them
tar zxvf archive_name
I get following error
Cannot open: Not a directory
What is the problem ?
Try extracting the archive in an empty directory; any existing files/directories in the extract target usually cause problems if names overlap.
I encountered the same issue (for each file within an archive) and I solved it by appending ".tar.gz" to the archive filename as I'd managed to download a PECL package without a file extension:
mv pecl_http pecl_http.tar.gz
I was then able to issue the following command to extract the contents of the archive:
tar -xzf pecl_http.tar.gz
You probably might already have a file with the same name that the tar is extracting a directory.
Try to tar in different location.
tar zxvf tar_name.tgz --one-top-level=new_directory_name
Try using tar -zxvf archive_name instead. I believe that the command format has changed, and it now requires the z (unzip) x (extract) v (verbose) f (filename...) parts as switches instead of plain text. The error comes from tar trying to do something to the file zxvf, which of course does not exist.

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