diff --git a/build.clj b/build.clj
index 7a942d3..d7c9f66 100644
--- a/build.clj
+++ b/build.clj
@@ -3,7 +3,7 @@
             [deps-deploy.deps-deploy :as dd]))
 
 (def lib 'org.clojars.some/depo)
-(def version "0.0.19")
+(def version "0.0.20")
 (def jar-file (format "target/%s-%s.jar" (name lib) version))
 (def class-dir "target/classes")
 (def url "https://github.com/somecho/depo")
diff --git a/src/depo/core.clj b/src/depo/core.clj
index 1e1f24c..af72da9 100644
--- a/src/depo/core.clj
+++ b/src/depo/core.clj
@@ -22,12 +22,16 @@
 (defn update-cmd [{:keys [_arguments file]}]
   (let [args  _arguments
         config-path (if file file (rw/get-config))]
-    (println args)))
+    (if (empty? args)
+      (do (mapv #(rw/update-dependency config-path %)
+                (rw/get-all-dependency-names config-path))
+          (println "Done!"))
+      (mapv #(rw/update-dependency config-path %) args))))
 
 (def CONFIGURATION
   {:command "depo"
    :description "Manage dependencies for Clojure projects easily"
-   :version "0.0.19"
+   :version "0.0.20"
    :opts [{:as "path to configuration file"
            :default nil
            :option "file"
diff --git a/src/depo/readwrite.clj b/src/depo/readwrite.clj
index f242496..5d9ef04 100644
--- a/src/depo/readwrite.clj
+++ b/src/depo/readwrite.clj
@@ -141,6 +141,30 @@
                                  :wrap-coll? nil}})
         (as-> new-conf (spit config-path new-conf)))))
 
+(defmulti get-all-dependency-names
+  "Returns all the dependencies from the config"
+  (fn [config-path] config-path))
+
+(defmethod get-all-dependency-names :default
+  [config-path]
+  (let [zloc (z/of-string (slurp config-path))]
+    (-> zloc
+        (z/get :deps)
+        (z/string)
+        (read-string)
+        (keys)
+        (as-> keys (map str keys)))))
+
+(defmethod get-all-dependency-names "project.clj"
+  [config-path]
+  (let [zloc (z/of-string (slurp config-path))]
+    (-> zloc
+        (z/find-value z/next :dependencies)
+        (z/next)
+        (z/string)
+        (read-string)
+        (as-> dep-vec (map #(str (first %)) dep-vec)))))
+
 (defmulti update-dependency
   "Updates a dependency in a Clojure project"
   (fn [config-path dependency] config-path))