Sangeeth Saravanaraj Sangeeth Saravanaraj - 2 months ago 18
C Question

What is the format specifier for unsigned short int?

I have the following program

#include <stdio.h>

int main(void)
{
unsigned short int length = 10;

printf("Enter length : ");
scanf("%u", &length);

printf("value is %u \n", length);

return 0;
}


Which when compiled using
gcc filename.c
issued the following warning (in the
scanf()
line).

warning: format ‘%u’ expects argument of type ‘unsigned int *’, but argument 2 has type ‘short unsigned int *’ [-Wformat]


I then referred the
C99 specification - 7.19.6 Formatted input/output functions
and couldn't understand the correct format specifier when using the length modifiers (like
short
,
long
, etc) with
unsigned
for
int
data type.

Is
%u
the correct specifier
unsigned short int
? If so why am I getting the above mentioned warning?!

EDIT:
Most of the time, I was trying
%uh
and it was still giving the warning.

Answer

Try using the "%h" modifier:

scanf("%hu", &length);
        ^

ISO/IEC 9899:201x - 7.21.6.1-7

Specifies that a following d , i , o , u , x , X , or n conversion specifier applies to an argument with type pointer to short or unsigned short.