int vfprintf( FILE *fp, char *fmt, va_list args )

FILE   *fp;             /* output stream pointer */

char   *fmt;            /* format string */

va_list args;           /* argument list */

Synopsis

#include "stdio.h"

#include "stdarg.h"

The vfprintf function writes text to the file associated with fp according to format string fmt . The arguments for fmt are specified in the variable argument list args

.

Parameters

fp is a stream pointer, open for output. fmt is a null-terminated string containing format specifications. args is of type va_list , a type suitable for holding information used by the variable argument macros. args should have been initialized by the va_start macro and perhaps modified by subsequent va_arg calls.

Return Value

vfprintf returns the number of characters printed.

Comments

vfprintf is identical to fprintf, except that the variable argument list has been replaced by the va_list args .

The types of arguments must match those expected by the format specifiers in fmt , and the number of arguments must be greater than or equal to the number of specifiers in fmt ; otherwise, the result of vfprintf is undefined.

See Also

fprintf for a description of permissible format specifiers.