C-printf实现

int myprintf(const char *format,...)
{
  va_list arg;
  int strlen;
  char str[200];

  va_start(arg, format);
  strlen = vsprintf(str,format, arg); //将数据填入str中,并返回str大小
  va_end(arg);

  printf("myprintf len:%d,str:%s
",strlen,str);

  return strlen;
}

int main()
{
   myprintf("%s,%s","123","456");

   myprintf("%s,%.2f %.2f %d","123",12.35,5.555,120);

    return 0;

}

打印如下: