bash: extract only part of tar.gz archive

Question

I have a very large .tar.gz file which I can't extract all together because of lack of space. I would like to extract half of its contents, process them, and then extract the remaining half.

The archive contains several subdirectories, which in turn contain files. When I extract a subdirectory, I need all its contents to be extracted with it.

What's the best way of doing this in bash? Does tar already allow this?

Answer 1

You can also extract one by one using

tar zxvf file.tar.gz PATH/to/file/inside_archive -C DESTINATION/dir

You can include a script around this:

1) Keep the PATH and DESTINATION same (yes you can use your own base directory for DESTINATION)

2) You can get the path for a file inside archive using

tar -ztvf file.tar.gz

3) You can use a for loop like for files in $(tar -ztvf file.tar.gz | awk '{print $NF}') and define a break condition as per requirement.

I would have done something like:

#!/bin/bash
for files in $(tar -ztvf file.tar.gz| awk '{print $NF}')
do 
subDir=$(dirname $files)
echo $subDir     
tar -C ./My_localDir/${subDir} -zxvf file.tar.gz $files 
done

$subDir contains the name of the sub Directories

Add a break condition to above according to your requirement.

Answer 2

You can for example extract only files which match some pattern:

tar -xvzf largefile.tar.gz --wildcards --no-anchored '*.html'

So, depending on the largefile.tar structure one can extract files with one pattern -> process them -> after that delete files -> extract files with another pattern, and so on.