char_hex_print.c

#include <stdio.h>

void printhex(signed char c) {
  printf("%x %d\n", c , c );
}

int main(){
  printhex(0x0);   /*  =>  0         0    */
  printhex(0x30);  /*  =>  30        48   */
  printhex(0x1f);  /*  =>  1f        28   */
  printhex(0x7c);  /*  =>  7c        124  */
  printhex(0xe4);  /*  =>  ffffffe4  -28  */ /* << WHAT???? */
  return 0;
}