int MGOprintf (char *format, ...)
The MGOprintf() function writes the format string to the server, interpreting '%' directives and '\' escapes in the same way as printf(). The format argument is re-used as many times as necessary to convert all of the given arguments.
Extensions to the usual set of '%' directives include '%q', which will properly quote any embedded '(' and ')' characters in the string, and '%b', which hexify the string.
Returns the number of characters sent upon success (zero indicates nothing was written) or -1 if an error occurred (in which case MGOerrno and MGOerrmsg are set appropriately).