node without arguments starts the REPL

bin/node-repl

@@ -1,8 +1,9 @@
 #!/usr/bin/env node
 
-puts = require("sys").puts;
+var puts = require("sys").puts;
 
 puts("Type '.help' for options.");
+puts("(The REPL can also be started by typing 'node' without arguments)");
 
 require('repl').start();
 

lib/module.js

@@ -441,16 +441,6 @@ Module.prototype._waitChildrenLoad = function (callback) {
 
 // bootstrap main module.
 exports.runMain = function () {
-  var cwd = process.cwd();
-
-  // Make process.argv[0] and process.argv[1] into full paths.
-  if (process.argv[0].indexOf('/') > 0) {
-    process.argv[0] = path.join(cwd, process.argv[0]);
-  }
-
-  if (process.argv[1].charAt(0) != "/" && !(/^http:\/\//).exec(process.argv[1])) {
-    process.argv[1] = path.join(cwd, process.argv[1]);
-  }
 
   // Load the main module--the command line argument.
   process.mainModule = new Module(".");

src/node.cc

@@ -2098,14 +2098,6 @@ int main(int argc, char *argv[]) {
   // in the command line))
   V8::SetFlagsFromCommandLine(&node::option_end_index, argv, false);
 
-  // Error out if we don't have a script argument.
-  if (argc < 2) {
-    fprintf(stderr, "No script was specified.\n");
-    node::PrintHelp();
-    return 1;
-  }
-
-
   // Ignore SIGPIPE
   struct sigaction sa;
   bzero(&sa, sizeof(sa));

src/node.js

@@ -192,9 +192,26 @@ process.exit = function (code) {
   process.reallyExit(code);
 };
 
+var cwd = process.cwd();
+var path = module.requireNative('path');
 
-module.runMain();
+// Make process.argv[0] and process.argv[1] into full paths.
+if (process.argv[0].indexOf('/') > 0) {
+  process.argv[0] = path.join(cwd, process.argv[0]);
+}
+
+if (process.argv[1]) {
+  if (process.argv[1].charAt(0) != "/" && !(/^http:\/\//).exec(process.argv[1])) {
+    process.argv[1] = path.join(cwd, process.argv[1]);
+  }
 
+  module.runMain();
+} else {
+  // No arguments, run the repl
+  var repl = module.requireNative('repl');
+  process.stdout.write("Type '.help' for options.\n");
+  repl.start();
+}
 
 // All our arguments are loaded. We've evaluated all of the scripts. We
 // might even have created TCP servers. Now we enter the main eventloop. If