Fix meta+character keys on mac

lib/tty_posix.js

@@ -66,6 +66,7 @@ ReadStream.prototype.isTTY = true;
   Some patterns seen in terminal key escape codes, derived from combos seen
   at http://www.midnight-commander.org/browser/lib/tty/key.c
 
+  ESC letter
   ESC [ letter
   ESC [ modifier letter
   ESC [ 1 ; modifier letter
@@ -89,8 +90,9 @@ ReadStream.prototype.isTTY = true;
   - two leading ESCs apparently mean the same as one leading ESC
 */
 
-// Regex used for ansi escape code splitting
-var splitKeyCodeRe =
+// Regexes used for ansi escape code splitting
+var metaKeyCodeRe = /^(?:\x1b)([a-zA-Z0-9])$/,
+    functionKeyCodeRe =
       /^(?:\x1b+)(O|N|\[|\[\[)(?:(\d+)(?:;(\d+))?([~^$])|(?:1;(\d+))?([a-zA-Z]))/;
 
 ReadStream.prototype._emitKey = function(s) {
@@ -140,7 +142,13 @@ ReadStream.prototype._emitKey = function(s) {
     key.name = s.toLowerCase();
     key.shift = true;
 
-  } else if (parts = splitKeyCodeRe.exec(s)) {
+  } else if (parts = metaKeyCodeRe.exec(s)) {
+    // meta+character key
+    key.name = parts[1].toLowerCase();
+    key.meta = true;
+    key.shift = /^[A-Z]$/.test(parts[1]);
+
+  } else if (parts = functionKeyCodeRe.exec(s)) {
     // ansi escape sequence
 
     // reassemble the key code leaving out leading \x1b's,