i need help with the "cp" command.

UNIX-based and UNIX-like systems will automatically OVERWRITE a file in the destination location from the source location IF the file is the same name.

is there a way for me to do something like this?

OVERWRITE the destination file ONLY IF the size of the source file and the size of the destination file are different. if the sizes are the same, don't overwrite and move on.

anyone know? can anyone help?