node/node-repl

#!/usr/bin/env node

node.stdio.open();

var buffered_cmd = '';

function prompt () {
  node.stdio.write(buffered_cmd.length ? '...   ' : "\nnode> ");
}

node.stdio.write("Welcome to the Node.js REPL.\n");
node.stdio.write("Enter ECMAScript at the prompt.\n");
node.stdio.write("Type Control-D to exit.\n");
node.stdio.write("For more information, see http://tinyclouds.org/node\n");

prompt();

var trimmer = /^\s*(.+)\s*$/m;

node.stdio.addListener("data", function (cmd) {
  var matches = trimmer.exec(cmd);

  if (matches && matches.length == 2) {
    cmd = matches[1];
    try {
      buffered_cmd += cmd;
      try {
        node.stdio.write(JSON.stringify(eval(buffered_cmd)) + "\n");
        buffered_cmd = '';
      } catch (e) { 
        if (!(e instanceof SyntaxError)) 
          throw e;
      }
    } catch (e) {
      node.stdio.writeError('caught an exception: ' + e + '\n');
      buffered_cmd = '';
    }
  }

  prompt();
});

// vim:ft=javascript