C/Macro Preprocessor/Preprocessor
Define preprocessor for char set
#include <stdio.h>
/* define CHAR_SET as either 256 or 128 */
#define CHAR_SET 256
int main(void)
{
int i;
#if CHAR_SET == 256
printf("Displaying full ASCII character set plus extensions.\n");
#else
printf("Displaying only ASCII character set.\n");
#endif
for(i = 0; i < CHAR_SET; i++)
printf("%c", i);
return 0;
}