cpp/io/c/vfprintf

Loads the data from the locations, defined by, converts them to character string equivalents and writes the results to a variety of sinks.

@1@ Writes the results to stdout. @2@ Writes the results to a file stream. @3@ Writes the results to a character string. @4@ Writes the results to a character string. At most characters are written. The resulting character string will be terminated with a null character, unless is zero. If is zero, nothing is written and  may be a null pointer, however the return value (number of bytes that would be written not including the null terminator) is still calculated and returned.

Return value
@1-3@ Number of characters written if successful or negative value if an error occurred.

@4@ Number of characters written if successful or negative value if an error occurred. If the resulting string gets truncated due to limit, function returns the total number of characters (not including the terminating null-byte) which would have been written, if the limit was not imposed.