vprintf(3s) vprintf(3s)
Name
vprintf, vfprintf, vsprintf - print formatted output of a varargs argument list
Syntax
#include <stdio.h>
#include <varargs.h>
int vprintf (format, ap)
char *format;
va_list ap;
int vfprintf (stream, format, ap)
FILE *stream;
char *format;
va_list ap;
int vsprintf (s, format, ap)
char *s, *format;
va_list ap;
Description
The and routines are the same as and respectively, except that instead of being called with a variable number of arguments, they are called
with an argument list as defined by
Examples
The following demonstrates how could be used to write an error routine.
#include <stdio.h>
#include <varargs.h>
.
.
.
/*
* error should be called like
* error(function_name, format, arg1, arg2...);
*/
/*VARARGS0*/
void
error(va_alist)
/* Note that the function_name and format arguments cannot be
* separately declared because of the definition of varargs.
*/
va_dcl
{
va_list args;
char *fmt;
va_start(args);
/* print out name of function causing error */
(void)fprintf(stderr, "ERROR in %s: ", va_arg(args, char *));
fmt = va_arg(args, char *);
/* print out remainder of message */
(void)vfprintf(stderr, fmt, args);
va_end(args);
(void)abort( );
}
See Also
varargs(3)
vprintf(3s)
