Outputs a variable parameter list to the specified stream input/output file according to a format.

[Format]

#include <stdarg.h>

#include <stdio.h>

long vfprintf (FILE *fp, const char *control, va_list arg);

[Parameters]

fp File pointer

control Pointer to string indicating format

arg Parameter list

[Return values]

Normal: Number of characters converted and output

Abnormal: Negative value

[Remarks]

The vfprintf function sequentially converts and edits a variable parameter list according to the string that represents the format pointed to by control, and outputs the result to the stream input/output file indicated by fp.

The vfprintf function returns the number of data items converted and output, or a negative value when an error occurs.

Within the vfprintf function, the va_end macro is not invoked.

For details of the format specifications, see the description of the fprintf function.

Parameter arg, indicating the parameter list, must be initialized beforehand by the va_start macro (and the succeeding va_arg macro).