m flag request

[iorixxx]

Hi Zainab thank your for your code. It would be great if you could implement -m flag too.

-m The number of characters in each input file is written to the
standard output. If the current locale does not support multibyte
characters, this is equivalent to the -c option. This will cancel
out any prior usage of the -c option.

[Zeesky-code]

I have implemented the -m flag in the latest commit:
911f19d

I'll be closing the issue as completed.