#include "stdio.h"
#include "stdarg.h"
void minprintf(char *fmt, ...);
void errmsg(int code, ...);
int errorf(const char *format, ...);
int sum(int num, ...);
int sum1(int num, ...);

int FILENAME=1, LINENUMBER=2, WARN=4;

main(int argc, char *argv[])
{
   char *s = "HELLO";  int x = 10;   double f = 10.0;

errmsg(1, "<FILE>", "cannot open %s\n", "a_file");
errmsg(3,"<FILE>",7,"cannot open %s\n","a_file");
errmsg(2, 7, "cannot open %s\n", "a_file");
errmsg(4, "<FILE> %s, x=%d", "a_file", 10);

minprintf("x = %d, f = %f, s = %s\n", x, f, s);
minprintf("s = %s, x = %d, f = %f, s = %s\n", s, x, f, s);

errorf("x = %d, f = %f, s = %s\n", x, f, s);

printf("sum = %d\n", sum(4, 1, 2, 3, 4));
printf("sum1 = %d\n", sum1(4, 1, 2, 3, 4));
//sum1(4, 1, 2, 3, 4);
}
int errorf(const char *format, ...)
{
 static int num_errors = 0;

 int n;
 va_list ap;

 num_errors++;
 fprintf(stderr, " ** Error %d: ", num_errors);
 va_start(ap, format);
 n = vfprintf(stderr, format, ap);
 va_end(ap);
 fprintf(stderr, "\n");
 return n;
}

void errmsg(int code, ...)
{
 va_list ap;  char *fmt;

 va_start(ap, code);

 if (code&FILENAME)
(void)fprintf(stderr, "\"%s\":", va_arg(ap, char *));

 if (code&LINENUMBER)
(void)fprintf(stderr, "%d:", va_arg(ap, int));

 if (code&WARN) (void)fputs("Warning:", stderr);

 fmt = va_arg(ap, char *);
 (void) vfprintf(stderr, fmt, ap);

va_end(ap);
}

int sum(int num, ...)
{
 va_list ap;
 int i, n = 0;

 va_start(ap, num);

 for (i=0; i<num; i++) n += va_arg(ap, int);
 return n;
}


int sum1(int num, ...)
{
 va_list ap;
 int i=0, t, n = 0;

 va_start(ap, num);
 n = num;
 printf("%d\n", n);
 while (1) {
     t = va_arg(ap, int);
     if (t<0) break;
     n += t;
     //if (i<0)printf("%d,%d\n", ++i, t);

 }
 return n;
}

// call example: minprintf("x = %d, f = %f, s = %s\n", x, f, s);
void minprintf(char *fmt, ...)
{
 va_list ap; char *p, *sval; int ival; double dval;

 va_start(ap, fmt);

 for(p=fmt; *p; p++){
   if (*p != '%'){
      putchar(*p);
      continue;
   }
   switch (*++p){
      case 'd':
        ival = va_arg(ap, int);
        printf("%d", ival);
        break;
      case 'f':
        dval = va_arg(ap, double);
        printf("%f", dval);
        break;
      case 's':
        for (sval=va_arg(ap, char *); *sval; sval++)
            putchar(*sval);
        break;
      default:
        putchar(*sval);
        break;
   }
 }
 va_end(ap);
}