potentially use sprintf function.

lib/tput.js

@@ -553,15 +553,15 @@ Tput.prototype._compile = function(val) {
     //   operator.
     // e.g. %:-d %+d %#x %+10d
     if (read(/^%(:-|[+# ])?(\d+(?:\.\d+)?)?([doxXs])/)) {
-      // var flag = cap[1]
-      //   , width = cap[2]
-      //   , type = cap[3];
+      // echo('sprintf("'+ cap[0].replace(':-', '-') + '", stack.pop())');
+      // var flag = cap[1], width = cap[2], type = cap[3];
       echo('stack.pop()');
       continue;
     }
 
     // %c   print pop() like %c in printf
     if (read(/^%c/)) {
+      // echo('sprintf("%c", stack.pop())');
       echo('stack.pop()');
       continue;
     }