update packages to latest version

node_modules/latest/index.js

@@ -0,0 +1,48 @@
+var npm = require('npm');
+var util = require('util');
+
+module.exports = latest;
+module.exports.checkupdate = checkupdate;
+
+/**
+ * get the latest version of a package
+ */
+function latest(name, cb) {
+  npm.load({name: name, loglevel: 'silent'}, function(err) {
+    if (err) return cb(err);
+    npm.commands.show([name, 'versions'], true, function(err, data) {
+      if (err) return cb(err);
+      var versions = data[Object.keys(data)[0]].versions;
+      var latest = versions[versions.length - 1];
+      cb(null, latest);
+    });
+  });
+};
+
+/**
+ * Convenience method
+ *
+ * Given a package.json style obj, determine if there are updates available
+ *
+ * Optionally, give true as a second argument to exit after writing the message
+ */
+function checkupdate(package, cb) {
+  latest(package.name, function(err, v) {
+    var s = '';
+    var ret = 0;
+    if (err) {
+      s = ">>> couldn't determine latest version";
+      ret = 2;
+    } else if (v !== package.version) {
+      s = util.format('>>> you are running version %s, a newer version %s is available\n',
+          package.version, v);
+      s += util.format('>>> consider updating with: [sudo] npm update -g %s',
+          package.name);
+      ret = 1;
+    } else {
+      s = util.format('you are running the latest version %s', package.version);
+      ret = 0;
+    }
+    cb(ret, s);
+  });
+};