Write a script that will report the cumulative size of all the files in and below a given directory. Your script will also report the name and size (in bytes) of the largest file with that directory tree. Your script will also report the percentage of space used (for that "largest" file) relative to the total cumulative size of all files. In this case, only select plain files (no symbolic links or directories).

Your script will accept a single directory argument. You script will perform argument checking to make sure that there is only one argument and that the argument is an existing directory. Your script needs to handle the cases when all the file sizes are zero or the given directory is empty. In other words, watch out for divide by zero errors. Use the find command to traverse the directory and search for "plain files" and generate the "long listing" for each file. Use the awk command to calculate the sum of the file sizes.

Test your script.

You may use the touch command to create a file with a specific size (see the man page). Be careful not to exceed any disk quota that may have been imposed on your account by the system admin.