Question

Write a script named listEmptyDir.sh that will do the following: (a) take a name of a directory as a parameter; (b) loop through all files in this directory and display their names; (c) if a file is a directory and has no files in it (empty directory), add the name of this empty directory to the file EmptyDir.txt in your current directory. If the number of parameters is not 1 or a parameter is not a directory, display the “usage” message and exit with non-zero status. Your script should demonstrate that you have investigated all possible situations.

Please don't just copy the one that already exist it doesn't explain the process well

Answer 1

usage() {
  echo "usage: " $0 " requires an existing path to a directory or a directory in the relative path"
  echo "[-h|--help] : display this message"
}

checkDir() {
  directory=$1
  notEmpty=false
  # if anything exists in the current directory
  if [[ "$(ls -A $directory)" ]]; then
    echo Files in subdirectors of $1
    #  for every sub file or directory in the current direcotry
    for sub in $directory/*; do
      # if the current path is a file then output the name
      if [[ -f $sub ]]; then
        echo $sub
        # mark the file as not empty
        notEmpty=true
      # else call the checkDir function again
      else
        checkDir $sub
        # if the current path is empty put it at the bottom of empty dir
        if [[ "$notEmpty"=false ]]; then
          echo $sub >> EmptyDir.txt
        fi
      fi
    done
  fi
}

directory=$1

if [[ "$#" != '1' ]] || [[ "$directory" = "-h" ]] || { ! [[  -p "$directory" ]] && ! [[ -d "$directory" ]]; }; then
  usage
  exit 1
fi

# null out EmptyDir
truncate -s 0 EmptyDir.txt

checkDir $directory

# showing contents of EmptyDirs
echo Empty Subdirectors of $1
cat EmptyDir.txt