具体的函数当然要根据你的应用目的来编写,MSDN上对此概念已经介绍的很清楚了,你看一下例子就会明白。
va_arg retrieves a value of type from the location given by arg_ptr and increments arg_ptr to point to the next argument in the list, using the size of type to determine where the next argument starts. va_arg can be used any number of times within the function to retrieve the arguments from the list.
printf( fmt,a );???
print("..")
一个例子:
/* VA.C: The program below illustrates passing a variable
* number of arguments using the following macros:
* va_start va_arg va_end
* va_list va_dcl (UNIX only)
*/
#include <stdio.h>
#define ANSI /* Comment out for UNIX version */
#ifdef ANSI /* ANSI compatible version */
#include <stdarg.h>
int average( int first, ... );
#else /* UNIX compatible version */
#include <varargs.h>
int average( va_list );
#endif
void main( void )
{
/* Call with 3 integers (-1 is used as terminator). */
printf( "Average is: %d\n", average( 2, 3, 4, -1 ) );
/* Call with 4 integers. */
printf( "Average is: %d\n", average( 5, 7, 9, 11, -1 ) );
/* Call with just -1 terminator. */
printf( "Average is: %d\n", average( -1 ) );
}
/* Returns the average of a variable list of integers. */
#ifdef ANSI /* ANSI compatible version */
int average( int first, ... )
{
int count = 0, sum = 0, i = first;
va_list marker;
va_start( marker, first ); /* Initialize variable arguments. */
while( i != -1 )
{
sum += i;
count++;
i = va_arg( marker, int);
}
va_end( marker ); /* Reset variable arguments. */
return( sum ? (sum / count) : 0 );
}
#else /* UNIX compatible version must use old-style definition. */
int average( va_alist )
va_dcl
{
int i, count, sum;
va_list marker;