C - scanf unsigned char

Question

I am trying to use scanf() for reading an unsigned char value with %hhu , but the compiler returned me:

error: unknown conversion type character 'h' in format
 [-Werror=format]| // line 3 error: too many arguments for format
 [-Werror=format-extra-args]| // line 3 

With this following code:

printf("Enter a number: ");
unsigned char nb;
scanf("%hhu", &nb); // line 3
printf("Number: %u\n", nb);
return (nb);

Answer 1

A discussion on this issue can be found here . This is specific to MinGW.
From this comment in the discussion the issue is identified as:

This is most likely related to bug https://sourceforge.net/p/mingw-w64/bugs/652/ in that the include order and compiler driver actually screws things up with respect to C standard output and format specifiers.

And is proposed solution is:

to always define __USE_MINGW_ANSI_STDIO so that the newer ansi format specifiers can be used and to ensure that long double (at least) is not passed between MSVC compiled and gcc compiled code.