I/O format of integer types

The following macros are defined in inttypes.h. Each expands to a character string literal containing a conversion specifier which can be modified by a length modifier that can be used in the format argument of a formatted input/output function when converting the corresponding integer type. These macros have the general form of PRI (character string literals for the fprintf() and fwprintf() family of functions) or SCN (character string literals for the fscanf() and fwscanf() family of functions), followed by the conversion specifier, followed by a name corresponding to a similar type name in <inttypes.h>. In these names, the suffix number represents the width of the type. For example, PRIdFAST32 can be used in a format string to print the value of an integer of type int_fast32_t.

Decimal notation

example:

#define _ISOC99_SOURCE
#include <inttypes.h>      
#include <stdio.h> 
int main(void)                                             
{                                                          

int8_t i =  40; 
printf("Demonstrating the use of the following macros:\n");
printf("Using PRId8, the printed value of 40 "                  
"is  %" PRId8"\n", i);                                    
printf("Using PRIiFAST8, the printed value of 40 "               
"is  %" PRIiFAST8"\n", i);                                 
printf("Using PRIoLEAST8, the printed value of 40 "              
"is  %" PRIoLEAST8 "\n", i);                               
return 0;                                                  
}                          


Output:

Demonstrating the use of the following macros:  
Using PRId8, the printed value of 40 is  40     
Using PRIiFAST8, the printed value of 40 is  40 
Using PRIoLEAST8, the printed value of 40 is  50