Selectively extracting files of gzipped archives into new directories whose names are derived from the archive's filename

Question

I've got a folder with thousands of gzipped archive files that contain several XML files. Now I need a script that loops over all archive files and selectively extracts a file with a certain filename (i.e. fileofinterest.xml) into a directory that has to be created by using the filename of the gzipped archive without the extension tar.gz.

So here's a sample of the archive directory containing the gzipped archive files and the desired output-directory with generated directories and extracted files:

home/
├─ archives/
│  ├─ archive.20.01.tar.gz
│  ├─ archive.20.02.tar.gz
├─ extracted/
│  ├─ archive.20.01/
│  │  ├─ fileofinterest.xml
│  ├─ archive.20.02/
│  │  ├─ fileofinterest.xml

This is my code so far, creation of directories is completely missing:

for f in ./*.tar.gz; do echo "Processing $f"; tar -x -f $f -C ../extracted/ fileofinterest.xml; done

Answer 1

If you're using bash (not ash or similar POSIX-limited shell), you could do something like this:

for f in ./*.tar.gz; do
  dir="../extracted/${f/%.tar.gz}"
  mkdir -p "$dir"
  echo "Processing $f"
  tar -x -f "$f" -C "$dir" fileofinterest.xml
done

Note: $dir will have values like ../extracted/./archive.20.01, but (except for aesthetics) this doesn't matter, any extra ./ directories in a path are effectively ignored. If it bothers you, add dir=${dir/\/.\//\/} before the mkdir -p.

Otherwise, you could use basename:

for f in ./*.tar.gz; do
  dir="../extracted/$(basename "$f" .tar.gz)"
  mkdir -p "$dir"
  echo "Processing $f"
  tar -x -f "$f" -C "$dir" fileofinterest.xml
done

Answer 2

Untested, but should get you in the right direction:

for f in *.tar.gz; 
do 
    echo "Processing $f"
    BaseName=${f::-6}
    mkdir ../extracted/$BaseName
    tar -x -f $f -C ../extracted/$BaseName fileofinterest.xml
done