That only works when the files you want to compare are in the same folder and next to each other. If you just want to know how big a given file is, then you hav

That only works when the files you want to compare are in the same folder and next to each other. If you just want to know how big a given file is, then you have to count the digits. And IIRC ls doesn't even print commas like that to make it human readable. It's just a blob of digits with more precision than is reasonably necessary for the vast majority of uses.