HP-UX Reference (11i v2 07/12) - 5 Miscellaneous (vol 9)

varargs(5) varargs(5)

* a second file pointer has been passed in to print general

* message information to. The rest of the format string is

* a standard printf(3S) format string.

if ((*fmt == ’%’) && (*(fmt + 1) == ’Y’))

{

FILE *other_fp;

fmt += 2;

other_fp = (FILE *) va_arg(ap, char *);

if (other_fp != (FILE *) NULL)

{

* Print general message information to additional stream.

(void) vfprintf(other_fp, fmt, ap);

(void) fflush(other_fp);

}

* Now print it to the log file.

(void) vfprintf(log_fp, fmt, ap);

}

WARNINGS

It is up to the calling routine to specify how many arguments there are, because it is not always possible to

determine this from the stack frame. For example, execl() is passed a zero pointer to signal the end of

the list. printf() can determine how many arguments are present by the format.

It is non-portable to specify a second argument of char, short,or float to

va_arg, because argu-

ments seen by the called function are not

char, short,orfloat. C converts

char and short argu-

ments to

int, and converts float arguments to double, before passing them to a function.