#include <stdarg.h>
#include <string.h>
#include <jsapi.h>
#include <sys/types.h>

size_t JSString_to_CString(JSString *str, char **msg){
	*msg = JS_GetStringBytes(str); /* Then convert it to a C-style string. */
	return JS_GetStringLength(str); /* Get the length of the string, # of chars. */
}

jsval printf_exception(JSContext *cx, char *msg, ...){
	char *str=NULL;
	int len = 0;
	va_list args;
	JSString *exceptionDescription;

	va_start(args, msg);
	len = vsnprintf(NULL, 0, msg, args)+1;
	va_end(args);

	str = JS_malloc(cx, len);
	memset(str, 0, len);

	va_start(args, msg);
	vsnprintf(str, len, msg, args);
	va_end(args);

	exceptionDescription = JS_NewString(cx, str, len);
	return STRING_TO_JSVAL(exceptionDescription);
}