How can I recursively unzip files that matches a pattern in a group of nested ZIP files?

I have a bunch of zip files, with several levels of zip files inside them.

I only want to extract files that matches this pattern: "_dnbr6.tif" and they can be located at different levels of the zip/directories hierarchy.

One extra hint is that the files I'm looking for are located in directories/zip files (inside zip files) named like "fire_bundle". Lower and upper case changes on different zip/directories.

How can I do it without extracting all the files of each of the nested zip files?

I guess the idea is to:

Iterate over each zip file listing all the files inside, if my file pattern matches then extract it.
If not, match my zip pattern (fire_bundle) and extract only that zip file and recursively look for my file pattern (list the files inside that zip, etc.)

I still don't know how to do the recursive part, so any help is appreciated.

Solution

Here is a script that will recursively search all the .zip files within the starting .zip file looking for the target file "_dnbr6.tif".

#!/bin/bash

targetFile="_dnbr6.tif"
sandboxDir="sandbox"

usage () {
  cat <<EOF
Usage $(basename $0) zipfile

This script will extract all the target files ($targetFile) from the provided
.zip file, including any that are in embedded in any .zip files included within it.
It puts all the files in a sandbox directory name $sandboxDir. This directory
must not already exist.
EOF
}

if [ -z "$1" ]; then
  usage
  exit 1
fi

if [ -d $sandboxDir ]; then
  echo "Error, the sandbox directory $sandboxDir already exists."
  echo
  usage
  exit 1
fi

mkdir $sandboxDir
cd $sandboxDir
startDir=$(pwd)

# Extract the initial .zip file looking for either the target file or additional .zip files.
unzip -q ../$1 "*.zip" "*$targetFile" 2>&1 | fgrep -v "filename not matched"   # Suppress the "filename not matched" message.

zipFiles="../$1"   # Just set to get past the first interation of the while loop.
#
# Loop until there aren't any .zip files anymore.
while [ ! -z "$zipFiles" ]; do
  zipFiles=$(find . -name '*.zip')
  if [ ! -z "$zipFiles" ]; then
    #
    # For each .zip file, extract any .zip files and the target file.
    for zipFile in $zipFiles; do
      cd $(dirname $zipFile)
      unzip -q ${startDir}/$zipFile "*.zip" "*$targetFile" 2>&1 | fgrep -v "filename not matched"
      rm ${startDir}/$zipFile
      cd $startDir
    done
  fi
done

echo "The target file '$targetFile' was extracted here:"
cd ..
find $sandboxDir -name "$targetFile"