copy_files_when_size

#https://unix.stackexchange.com/questions/570743/cp-rsync-overwrite-if-smaller-backup-original-and-then-overwrite-if-larger
# get the size and filnames of files in '/tmp/A' directory and loop through each file found
ls /tmp/A | while read filename
do
  # get the size of file in 'A' directory
  sizeA=$( ls -l "/tmp/A/${filename}" | awk '{print $5}')

  # get the size of corresponding file in 'B' directory
  sizeB=$(ls -l "/tmp/B/${filename}" | awk '{print $5}')

  # compare file sizes and perform appropriate action
  if [ ${sizeB} -gt ${sizeA} ]
  then
    echo "file in B named \"${filename}\" is larger than A file"

    # Backup and overwrite the file
    cp "/tmp/B/${filename}" /tmp/C/
    cp -f "/tmp/A/${filename}" /tmp/B/

  else
    if [ ${sizeB} -lt ${sizeA} ]
    then
       echo "file in B named \"${filename}\" is smaller than A file"
       # overwrite the file
       cp -f "/tmp/A/${filename}" /tmp/B/
    else
       echo "The files \"${filename}\" are the same size"
    fi
  fi
done