Support name@version in cache add

lib/cache.js

@@ -16,14 +16,14 @@ var mkdir = require("./utils/mkdir-p")
   , registry = require("./utils/registry")
   , log = require("./utils/log")
   , path = require("path")
-  , sys = require("sys")
+  , sys = require("./utils/sys")
 
 cache.usage = "npm cache add <tarball file>"
             + "\nnpm cache add <folder>"
             + "\nnpm cache add <tarball url>"
-            + "\nnpm cache add <name> <version>"
+            + "\nnpm cache add <name>@<version>"
             + "\nnpm cache ls [<path>]"
-            + "\nnpm cache clean [<pkg> [<version>]]"
+            + "\nnpm cache clean [<pkg>[@<version>]]"
 
 function cache (args, cb) {
   var cmd = args.shift()
@@ -55,8 +55,11 @@ function read (name, ver, cb) {
   })
 }
 
-// npm cache ls [<pkg> [<ver>]]
+// npm cache ls [<pkg>[@<ver>]]
 function ls (args, cb) {
+  if (args[0] && args[0].indexOf("@") !== -1) {
+    args = args[0].split("@")
+  }
   var show = path.join.apply(path, args)
     , read = npm.cache
     , msg = "cache ls"+(show?" "+show:"")
@@ -82,6 +85,9 @@ function ls (args, cb) {
 function clean (args, cb) {
   if (!cb) cb = args, args = []
   if (!args) args = []
+  if (args[0] && args[0].indexOf("@") !== -1) {
+    args = args[0].split("@")
+  }
   var pkg = args.shift()
     , ver = args.shift()
     , clean = npm.cache
@@ -101,6 +107,9 @@ exports.add = function (pkg, ver, cb) {
   return add([pkg, ver], cb)
 }
 function add (args, cb) {
+  if (args[0] && args[0].indexOf("@") !== -1) {
+    args = args[0].split("@")
+  }
   var pkg = args.shift()
     , ver = args.shift()
   if (!pkg && !ver) {