Add binding to termios, implement readline for repl

bin/node-repl

@@ -2,10 +2,6 @@
 
 puts = require("sys").puts;
 
-puts("Welcome to the Node.js REPL.");
-puts("Enter ECMAScript at the prompt.");
-puts("Tip 1: Use 'rlwrap node-repl' for a better interface");
-puts("Tip 2: Type Control-D to exit.");
 puts("Type '.help' for options.");
 
 require('repl').start();

lib/readline.js

@@ -0,0 +1,251 @@
+// Insperation for this code comes from Salvatore Sanfilippo's linenoise.
+// http://github.com/antirez/linenoise
+// Reference:
+// * http://invisible-island.net/xterm/ctlseqs/ctlseqs.html
+// * http://www.3waylabs.com/nw/WWW/products/wizcon/vt220.html
+
+var kHistorySize = 30;
+var kBufSize = 10*1024;
+
+
+var Buffer = require('buffer').Buffer;
+var inherits = require('sys').inherits;
+var EventEmitter = require('events').EventEmitter;
+var stdio = process.binding('stdio');
+
+
+
+exports.createInterface = function (output, isTTY) {
+  return new Interface(output, isTTY);
+};
+
+function Interface (output, isTTY) {
+  this.output = output;
+
+  this.setPrompt("node> ");
+
+  // Current line
+  this.buf = new Buffer(kBufSize);
+  this.buf.used = 0;
+
+  if (!isTTY) {
+    this._tty = false;
+  } else {
+    // input refers to stdin
+
+    // Check process.env.TERM ?
+    stdio.setRawMode(true);
+    this._tty = true;
+    this.columns = stdio.getColumns();
+
+    // Cursor position on the line.
+    this.cursor = 0;
+
+    this.history = [];
+    this.historyIndex = -1;
+  }
+}
+
+inherits(Interface, EventEmitter);
+
+
+Interface.prototype.setPrompt = function (prompt, length) {
+  this._prompt = prompt;
+  this._promptLength = length ? length : Buffer.byteLength(prompt);
+};
+
+
+Interface.prototype.prompt  = function () {
+  if (this._tty) {
+    this.buf.used = 0;
+    this.cursor = 0;
+    this._refreshLine();
+  } else {
+    this.output.write(this._prompt);
+  }
+};
+
+
+Interface.prototype._addHistory = function () {
+  if (this.buf.used === 0) return "";
+
+  var b = new Buffer(this.buf.used);
+  this.buf.copy(b, 0, 0, this.buf.used);
+  this.buf.used = 0;
+
+  this.history.unshift(b);
+  this.historyIndex = -1;
+
+  this.cursor = 0;
+
+  // Only store so many
+  if (this.history.length > kHistorySize) this.history.pop();
+
+  return b.toString('utf8');
+};
+
+
+Interface.prototype._refreshLine  = function () {
+  if (this._closed) return;
+
+  stdio.setRawMode(true);
+
+  // Cursor to left edge.
+  this.output.write('\x1b[0G');
+
+  // Write the prompt and the current buffer content.
+  this.output.write(this._prompt);
+  if (this.buf.used > 0) {
+    this.output.write(this.buf.slice(0, this.buf.used));
+  }
+
+  // Erase to right.
+  this.output.write('\x1b[0K');
+
+  // Move cursor to original position.
+  this.output.write('\x1b[0G\x1b[' + (this._promptLength + this.cursor) + 'C');
+};
+
+
+Interface.prototype.close = function (d) {
+  if (this._tty) {
+    stdio.setRawMode(false);
+  }
+  this.emit('close');
+  this._closed = true;
+};
+
+
+Interface.prototype.write = function (d) {
+  if (this._closed) return;
+  return this._tty ? this._ttyWrite(d) : this._normalWrite(d);
+};
+
+
+Interface.prototype._normalWrite = function (b) {
+  for (var i = 0; i < b.length; i++) {
+    var code = b instanceof Buffer ? b[i] : b.charCodeAt(i);
+    if (code === '\n'.charCodeAt(0) || code === '\r'.charCodeAt(0)) {
+      var s = this.buf.toString('utf8', 0, this.buf.used);
+      this.emit('line', s);
+      this.buf.used = 0;
+    } else {
+      this.buf[this.buf.used++] = code;
+    }
+  }
+};
+
+
+Interface.prototype._ttyWrite = function (b) {
+  switch (b[0]) {
+    /* ctrl+c */
+    case 3:
+      //process.kill(process.pid, "SIGINT");
+      this.close();
+      break;
+
+    case 4:     /* ctrl+d */
+      this.close();
+      break;
+
+    case 13:    /* enter */
+      var line = this._addHistory();
+      this.output.write('\n\x1b[0G');
+      stdio.setRawMode(false);
+      this.emit('line', line);
+      break;
+
+    case 127:   /* backspace */
+    case 8:     /* ctrl+h */
+      if (this.cursor > 0 && this.buf.used > 0) {
+        for (var i = this.cursor; i < this.buf.used; i++) {
+          this.buf[i-1] = this.buf[i];
+        }
+        this.cursor--;
+        this.buf.used--;
+        this._refreshLine();
+      }
+      break;
+
+    case 21: /* Ctrl+u, delete the whole line. */
+      this.cursor = this.buf.used = 0;
+      this._refreshLine();
+      break;
+
+    case 11: /* Ctrl+k, delete from current to end of line. */
+      this.buf.used = this.cursor;
+      this._refreshLine();
+      break;
+
+    case 1: /* Ctrl+a, go to the start of the line */
+      this.cursor = 0;
+      this._refreshLine();
+      break;
+
+    case 5: /* ctrl+e, go to the end of the line */
+      this.cursor = this.buf.used;
+      this._refreshLine();
+      break;
+
+    case 27:    /* escape sequence */
+      if (b[1] === 91 && b[2] === 68) {
+        // left arrow
+        if (this.cursor > 0) {
+          this.cursor--;
+          this._refreshLine();
+        }
+      } else if (b[1] === 91 && b[2] === 67) {
+        // right arrow
+        if (this.cursor != this.buf.used) {
+          this.cursor++;
+          this._refreshLine();
+        }
+      } else if (b[1] === 91 && b[2] === 65) {
+        // up arrow
+        if (this.historyIndex + 1 < this.history.length) {
+          this.historyIndex++;
+          this.history[this.historyIndex].copy(this.buf, 0);
+          this.buf.used = this.history[this.historyIndex].length;
+          // set cursor to end of line.
+          this.cursor = this.buf.used;
+
+          this._refreshLine();
+        }
+
+      } else if (b[1] === 91 && b[2] === 66) {
+        // down arrow
+        if (this.historyIndex > 0) {
+          this.historyIndex--;
+          this.history[this.historyIndex].copy(this.buf, 0);
+          this.buf.used = this.history[this.historyIndex].length;
+          // set cursor to end of line.
+          this.cursor = this.buf.used;
+          this._refreshLine();
+
+        } else if (this.historyIndex === 0) {
+          this.historyIndex = -1;
+          this.cursor = 0;
+          this.buf.used = 0;
+          this._refreshLine();
+        }
+      }
+      break;
+
+    default:
+      if (this.buf.used < kBufSize) {
+        for (var i = this.buf.used + 1; this.cursor < i; i--) {
+          this.buf[i] = this.buf[i-1];
+        }
+        this.buf[this.cursor++] = b[0];
+        this.buf.used++;
+
+        if (this.buf.used == this.cursor) {
+          this.output.write(b);
+        } else {
+          this._refreshLine();
+        }
+      }
+      break;
+  }
+};
+

lib/repl.js

@@ -15,6 +15,7 @@
 var sys = require('sys');
 var evalcx = process.binding('evals').Script.runInNewContext;
 var path = require("path");
+var rl = require('readline');
 var scope;
 
 function cwdRequire (id) {
@@ -40,12 +41,79 @@ function REPLServer(prompt, stream) {
   if (!scope) setScope();
   self.scope = scope;
   self.buffered_cmd = '';
-  self.prompt = prompt || "node> ";
+
   self.stream = stream || process.openStdin();
-  self.stream.setEncoding('utf8');
+  self.prompt = "node> " || prompt;
+
+  var isTTY = (self.stream.fd < 3);
+  var rli = self.rli = rl.createInterface(self.stream, isTTY);
+  rli.setPrompt(self.prompt);
+
   self.stream.addListener("data", function (chunk) {
-    self.readline.call(self, chunk);
+    rli.write(chunk);
   });
+
+  rli.addListener('line', function (cmd) {
+    cmd = trimWhitespace(cmd);
+
+    var flushed = true;
+
+    // Check to see if a REPL keyword was used. If it returns true,
+    // display next prompt and return.
+    if (self.parseREPLKeyword(cmd) === true) return;
+
+    // The catchall for errors
+    try {
+      self.buffered_cmd += cmd;
+      // This try is for determining if the command is complete, or should
+      // continue onto the next line.
+      try {
+        // Scope the readline with self.scope
+        // with(){} and eval() are considered bad.
+        var ret = evalcx(self.buffered_cmd, scope, "repl");
+        if (ret !== undefined) {
+          scope._ = ret;
+          flushed = self.stream.write(exports.writer(ret) + "\n");
+        }
+
+        self.buffered_cmd = '';
+      } catch (e) {
+        // instanceof doesn't work across context switches.
+        if (!(e && e.constructor && e.constructor.name === "SyntaxError")) {
+          throw e;
+        }
+      }
+    } catch (e) {
+      // On error: Print the error and clear the buffer
+      if (e.stack) {
+        flushed = self.stream.write(e.stack + "\n");
+      } else {
+        flushed = self.stream.write(e.toString() + "\n");
+      }
+      self.buffered_cmd = '';
+    }
+
+    // need to make sure the buffer is flushed before displaying the prompt
+    // again. This is really ugly. Need to have callbacks from
+    // net.Stream.write()
+    if (flushed) {
+      self.displayPrompt();
+    } else {
+      self.displayPromptOnDrain = true;
+    }
+  });
+
+  self.stream.addListener('drain', function () {
+    if (self.displayPromptOnDrain) {
+      self.displayPrompt();
+      self.displayPromptOnDrain = false;
+    }
+  });
+
+  rli.addListener('close', function () {
+    self.stream.destroy();
+  });
+
   self.displayPrompt();
 }
 exports.REPLServer = REPLServer;
@@ -57,54 +125,12 @@ exports.start = function (prompt, source) {
 };
 
 REPLServer.prototype.displayPrompt = function () {
-  var self = this;
-  self.stream.write(self.buffered_cmd.length ? '...   ' : self.prompt);
+  this.rli.setPrompt(this.buffered_cmd.length ? '...   ' : this.prompt);
+  this.rli.prompt();
 };
 
 // read a line from the stream, then eval it
 REPLServer.prototype.readline = function (cmd) {
-  var self = this;
-
-  cmd = self.trimWhitespace(cmd);
-  
-  // Check to see if a REPL keyword was used. If it returns true,
-  // display next prompt and return.
-  if (self.parseREPLKeyword(cmd) === true) {
-    return;
-  }
-  
-  // The catchall for errors
-  try {
-    self.buffered_cmd += cmd;
-    // This try is for determining if the command is complete, or should
-    // continue onto the next line.
-    try {
-      // Scope the readline with self.scope
-      // with(){} and eval() are considered bad.
-      var ret = evalcx(self.buffered_cmd, scope, "repl");
-      if (ret !== undefined) {
-        scope._ = ret;
-        self.stream.write(exports.writer(ret) + "\n");
-      }
-
-      self.buffered_cmd = '';
-    } catch (e) {
-      // instanceof doesn't work across context switches.
-      if (!(e && e.constructor && e.constructor.name === "SyntaxError")) {
-        throw e;
-      }
-    }
-  } catch (e) {
-    // On error: Print the error and clear the buffer
-    if (e.stack) {
-      self.stream.write(e.stack + "\n");
-    } else {
-      self.stream.write(e.toString() + "\n");
-    }
-    self.buffered_cmd = '';
-  }
-  
-  self.displayPrompt();
 };
 
 /**
@@ -142,20 +168,14 @@ REPLServer.prototype.parseREPLKeyword = function (cmd) {
   return false;
 };
 
-/**
- * Trims Whitespace from a line.
- * 
- * @param {String} cmd The string to trim the whitespace from
- * @returns {String} The trimmed string 
- */
-REPLServer.prototype.trimWhitespace = function (cmd) {
+function trimWhitespace (cmd) {
   var trimmer = /^\s*(.+)\s*$/m, 
     matches = trimmer.exec(cmd);
 
   if (matches && matches.length === 2) {
     return matches[1];
   }
-};
+}
 
 /**
  * Converts commands that use var and function <name>() to use the

src/node.cc

@@ -976,6 +976,9 @@ const char* ToCString(const v8::String::Utf8Value& value) {
 static void ReportException(TryCatch &try_catch, bool show_line) {
   Handle<Message> message = try_catch.Message();
 
+  node::Stdio::DisableRawMode(STDIN_FILENO);
+  fprintf(stderr, "\n\n");
+
   if (show_line && !message.IsEmpty()) {
     // Print (filename):(line number): (message).
     String::Utf8Value filename(message->GetScriptResourceName());
@@ -1223,8 +1226,6 @@ static Handle<Value> SetUid(const Arguments& args) {
 
 v8::Handle<v8::Value> Exit(const v8::Arguments& args) {
   HandleScope scope;
-  fflush(stderr);
-  Stdio::Flush();
   exit(args[0]->IntegerValue());
   return Undefined();
 }
@@ -1855,6 +1856,7 @@ static Handle<Value> Binding(const Arguments& args) {
       exports->Set(String::New("posix"),        String::New(native_posix));
       exports->Set(String::New("querystring"),  String::New(native_querystring));
       exports->Set(String::New("repl"),         String::New(native_repl));
+      exports->Set(String::New("readline"),     String::New(native_readline));
       exports->Set(String::New("sys"),          String::New(native_sys));
       exports->Set(String::New("tcp"),          String::New(native_tcp));
       exports->Set(String::New("uri"),          String::New(native_uri));
@@ -2078,6 +2080,14 @@ static void ParseArgs(int *argc, char **argv) {
   option_end_index = i;
 }
 
+
+static void AtExit() {
+  node::Stdio::Flush();
+  node::Stdio::DisableRawMode(STDIN_FILENO);
+  fprintf(stderr, "\n");
+}
+
+
 }  // namespace node
 
 
@@ -2179,12 +2189,12 @@ int main(int argc, char *argv[]) {
   Persistent<Context> context = Context::New();
   Context::Scope context_scope(context);
 
+  atexit(node::AtExit);
+
   // Create all the objects, load modules, do everything.
   // so your next reading stop should be node::Load()!
   node::Load(argc, argv);
 
-  node::Stdio::Flush();
-
 #ifndef NDEBUG
   // Clean up.
   context.Dispose();

src/node_stdio.cc

@@ -6,6 +6,9 @@
 #include <string.h>
 #include <errno.h>
 
+#include <termios.h>
+#include <sys/ioctl.h>
+
 using namespace v8;
 namespace node {
 
@@ -14,6 +17,81 @@ static int stdout_flags = -1;
 static int stdin_flags = -1;
 
 
+static struct termios orig_termios; /* in order to restore at exit */
+static int rawmode = 0; /* for atexit() function to check if restore is needed*/
+
+
+static int EnableRawMode(int fd) {
+  struct termios raw;
+
+  if (rawmode) return 0;
+
+  //if (!isatty(fd)) goto fatal;
+  if (tcgetattr(fd, &orig_termios) == -1) goto fatal;
+
+  raw = orig_termios;  /* modify the original mode */
+  /* input modes: no break, no CR to NL, no parity check, no strip char,
+   * no start/stop output control. */
+  raw.c_iflag &= ~(BRKINT | ICRNL | INPCK | ISTRIP | IXON);
+  /* output modes - disable post processing */
+  raw.c_oflag &= ~(OPOST);
+  /* control modes - set 8 bit chars */
+  raw.c_cflag |= (CS8);
+  /* local modes - choing off, canonical off, no extended functions,
+   * no signal chars (^Z,^C) */
+  raw.c_lflag &= ~(ECHO | ICANON | IEXTEN | ISIG);
+  /* control chars - set return condition: min number of bytes and timer.
+   * We want read to return every single byte, without timeout. */
+  raw.c_cc[VMIN] = 1; raw.c_cc[VTIME] = 0; /* 1 byte, no timer */
+
+  /* put terminal in raw mode after flushing */
+  if (tcsetattr(fd, TCSAFLUSH, &raw) < 0) goto fatal;
+  rawmode = 1;
+  return 0;
+
+fatal:
+  errno = ENOTTY;
+  return -1;
+}
+
+
+void Stdio::DisableRawMode(int fd) {
+  /* Don't even check the return value as it's too late. */
+  if (rawmode && tcsetattr(fd, TCSAFLUSH, &orig_termios) != -1) {
+    rawmode = 0;
+  }
+}
+
+// process.binding('stdio').setRawMode(true);
+static Handle<Value> SetRawMode (const Arguments& args) {
+  HandleScope scope;
+
+  if (args[0]->IsFalse()) {
+    Stdio::DisableRawMode(STDIN_FILENO);
+  } else {
+    if (0 != EnableRawMode(STDIN_FILENO)) {
+      return ThrowException(ErrnoException(errno, "EnableRawMode"));
+    }
+  }
+
+  return rawmode ? True() : False();
+}
+
+
+// process.binding('stdio').getColumns();
+static Handle<Value> GetColumns (const Arguments& args) {
+  HandleScope scope;
+
+  struct winsize ws;
+
+  if (ioctl(1, TIOCGWINSZ, &ws) == -1) {
+    return scope.Close(Integer::New(80));
+  }
+
+  return scope.Close(Integer::NewFromUnsigned(ws.ws_col));
+}
+
+
 /* STDERR IS ALWAY SYNC ALWAYS UTF8 */
 static Handle<Value>
 WriteError (const Arguments& args)
@@ -94,13 +172,12 @@ void Stdio::Flush() {
     fcntl(STDIN_FILENO, F_SETFL, stdin_flags & ~O_NONBLOCK);
   }
 
-  if (STDOUT_FILENO >= 0) {
-    if (stdout_flags != -1) {
-      fcntl(STDOUT_FILENO, F_SETFL, stdout_flags & ~O_NONBLOCK);
-    }
-
-    close(STDOUT_FILENO);
+  if (stdout_flags != -1) {
+    fcntl(STDOUT_FILENO, F_SETFL, stdout_flags & ~O_NONBLOCK);
   }
+
+  fflush(stdout);
+  fflush(stderr);
 }
 
 
@@ -120,6 +197,8 @@ void Stdio::Initialize(v8::Handle<v8::Object> target) {
   NODE_SET_METHOD(target, "openStdin", OpenStdin);
   NODE_SET_METHOD(target, "isStdoutBlocking", IsStdoutBlocking);
   NODE_SET_METHOD(target, "isStdinBlocking", IsStdinBlocking);
+  NODE_SET_METHOD(target, "setRawMode", SetRawMode);
+  NODE_SET_METHOD(target, "getColumns", GetColumns);
 }
 
 

src/node_stdio.h

@@ -10,6 +10,7 @@ class Stdio  {
 public:
   static void Initialize (v8::Handle<v8::Object> target);
   static void Flush ();
+  static void DisableRawMode(int fd);
 };
 
 }  // namespace node