ultrix man page for vprintf

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)