If a user function needs to print output, it must use one of the
following functions. The normal C functions that print to
stdout such as
puts(), etc. must
not be used, as they will interfere with normal output and will not
be redirected to
<CAPTURE> as needed. These
functions do not automatically HTML-escape their output; the
format code must explicitly be used with
VXpf() for escapement.
VXpf(const char *fmt, ...)Replacement for
printf(); has the same syntax. Also understands the same extended codes that
VXwrite(const char *buf, size_t len)Prints
bufto the current output. Binary data is permitted.