Function rprintf

log.c:406–443

This is the rsync debugging function. Call it with FINFO, FERROR_*, * FWARNING, FLOG, or FCLIENT. */

/* This is the rsync debugging function. Call it with FINFO, FERROR_*,
 * FWARNING, FLOG, or FCLIENT. */
void rprintf(enum logcode code, const char *format, ...)
{
	va_list ap;
	char buf[BIGPATHBUFLEN];
	size_t len;

	va_start(ap, format);
	len = vsnprintf(buf, sizeof buf, format, ap);
	va_end(ap);

	/* Deal with buffer overruns.  Instead of panicking, just
	 * truncate the resulting string.  (Note that configure ensures
	 * that we have a vsnprintf() that doesn't ever return -1.) */
	if (len > sizeof buf - 1) {
		static const char ellipsis[] = "[...]";

		/* Reset length, and zero-terminate the end of our buffer */
		len = sizeof buf - 1;
		buf[len] = '\0';

		/* Copy the ellipsis to the end of the string, but give
		 * us one extra character:
		 *
		 *                  v--- null byte at buf[sizeof buf - 1]
		 *        abcdefghij0
		 *     -> abcd[...]00  <-- now two null bytes at end
		 *
		 * If the input format string has a trailing newline,
		 * we copy it into that extra null; if it doesn't, well,
		 * all we lose is one byte.  */
		memcpy(buf+len-sizeof ellipsis, ellipsis, sizeof ellipsis);
		if (format[strlen(format)-1] == '\n') {
			buf[len-1] = '\n';
		}
	}

	rwrite(code, buf, len, 0);
}

/* This is like rprintf, but it also tries to print some
 * representation of the error code.  Normally errcode = errno.