Write formatted output to a stream.

This function is compatible with the following targets:

ANSI

BeOS

EMB/RTOS

Mac OS

Palm OS

Win32

#include <stdarg.h>

#include <stdio.h>

int vfprintf(FILE *stream,

Parameters for this facility are:

stream	FILE *	A pointer to a FILE stream
format	const char *	The format string
arg	va_list	The variable argument list

The vfprintf() function works identically to the fprintf() function. Instead of the variable list of arguments that can be passed to fprintf(), vfprintf() accepts its arguments in the array arg of type va_list which must have been initialized by the va_start() macro from the stdarg.h header file. The vfprintf() does not invoke the va_end macro.

For specifications concerning the output control string and conversion specifiers please see: "Output Control String and Conversion Specifiers."

vfprintf() returns the number of characters written or EOF if it failed.

"Wide Character and Byte Character Stream Orientation"

"fprintf"

"printf"

"Overview of stdarg.h"

#include <stdio.h>
#include <stdlib.h>
#include <stdarg.h>

int fpr(FILE *, char *, ...);

int main(void)
{
	FILE *f;
	static char name[] = "foo";
	int a = 56, result;
	double x = 483.582;

	// create a new file for output
	if (( f = fopen(name, "w")) == NULL) {
		printf("Can't open %s.\n", name);
		exit(1);
	}

	// format and output a variable number of arguments
	// to the file
	result = fpr(f, "%10s %4.4f %-10d\n", name, x, a);

	// close the file
	fclose(f);

	return 0;
}

// fpr() formats and outputs a variable
// number of arguments to a stream using 
// the vfprintf() function
int fpr(FILE *stream, char *format, ...)
{
	va_list args;
	int retval;

	va_start(args, format);		// prepare the arguments
	retval = vfprintf(stream, format, args); 
	// output them
	va_end(args);					// clean the stack
	return retval;
}