update packages to latest version

node_modules/npm/lib/config/find-prefix.js

@@ -0,0 +1,56 @@
+// try to find the most reasonable prefix to use
+
+module.exports = findPrefix
+
+var fs = require("fs")
+var path = require("path")
+
+function findPrefix (p, cb_) {
+  function cb (er, p) {
+    process.nextTick(function () {
+      cb_(er, p)
+    })
+  }
+
+  p = path.resolve(p)
+  // if there's no node_modules folder, then
+  // walk up until we hopefully find one.
+  // if none anywhere, then use cwd.
+  var walkedUp = false
+  while (path.basename(p) === "node_modules") {
+    p = path.dirname(p)
+    walkedUp = true
+  }
+  if (walkedUp) return cb(null, p)
+
+  findPrefix_(p, p, cb)
+}
+
+function findPrefix_ (p, original, cb) {
+  if (p === "/"
+      || (process.platform === "win32" && p.match(/^[a-zA-Z]:(\\|\/)?$/))) {
+    return cb(null, original)
+  }
+  fs.readdir(p, function (er, files) {
+    // an error right away is a bad sign.
+    // unless the prefix was simply a non
+    // existent directory.
+    if (er && p === original) {
+      if (er.code === "ENOENT") return cb(null, original);
+      return cb(er)
+    }
+
+    // walked up too high or something.
+    if (er) return cb(null, original)
+
+    if (files.indexOf("node_modules") !== -1
+        || files.indexOf("package.json") !== -1) {
+      return cb(null, p)
+    }
+
+    var d = path.dirname(p)
+    if (d === p) return cb(null, original)
+
+    return findPrefix_(d, original, cb)
+  })
+}