//输出格式: hex2bin 5e.

//得到: 0101 1110

//======================================

#include
#include

char *bitstr(char *, void const *, size_t);

int main(int argc, char **argv)
{

   unsigned char value;
   char *pointer;
   char ebits[CHAR_BIT * sizeof value + 1];

  
   value = 0;

   for (pointer = argv[1]; *pointer; ++pointer) {
     value > 1) + 1;
      do {
         *str++ = (char)(mask & byte[n] ? '1' : '0');
         mask >>= 1;
      } while (mask);
   }
   *str = '';
   return ptr;
}