stdarg.h
stdarg.h定义于函数的可变参数相关的一些方法。
- va_list 类型
- va_start()
- va_arg()：获取当前参数
- va_end()。
va_copy()：it makes a copy of your va_list variable in the exact same state. va_copy() can be useful if you need to scan ahead through the arguments but need to also remember your current place.
接受可变函数作为参数的一些方法。
- vprintf()
- vfprintf()
- vsprintf()
- vsnprintf()
#include <stdio.h>
#include <stdarg.h>
int my_printf(int serial, const char *format, ...)
{
va_list va;
// Do my custom work
printf("The serial number is: %d\n", serial);
// Then pass the rest off to vprintf()
va_start(va, format);
int rv = vprintf(format, va);
va_end(va);
return rv;
}
int main(void)
{
int x = 10;
float y = 3.2;
my_printf(3490, "x is %d, y is %f\n", x, y);
}