Add flag to disable colors in REPL

lib/repl.js

@@ -20,6 +20,8 @@ var fs = require("fs");
 var rl = require('readline');
 var context;
 
+var disableColors = process.env.NODE_DISABLE_COLORS ? true : false;
+
 function cwdRequire (id) {
   if (id.match(/^\.\.\//) || id.match(/^\.\//)) {
     id = path.join(process.cwd(), id);
@@ -54,7 +56,7 @@ function REPLServer(prompt, stream) {
     return self.complete(text);
   });
 
-  if (rli.enabled) {
+  if (rli.enabled && !disableColors) {
     // Turn on ANSI coloring.
     exports.writer = function(obj, showHidden, depth) {
       return sys.inspect(obj, showHidden, depth, true);

src/node.cc

@@ -1733,6 +1733,7 @@ static void PrintHelp() {
          "NODE_DEBUG           Print additional debugging output.\n"
          "NODE_MODULE_CONTEXTS Set to 1 to load modules in their own\n"
          "                     global contexts.\n"
+         "NODE_DISABLE_COLORS  Set to 1 to disable colors in the REPL\n"
          "\n"
          "Documentation can be found at http://nodejs.org/api.html"
          " or with 'man node'\n");