From 62e727f4dc7f299c016d90a1679a97748dfcd26f Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Tue, 23 Jun 2020 22:57:10 +0200
Subject: [PATCH 01/19] move helper functions to separate namespace

---
 project.clj                          |  2 +-
 src/de/mzuther/moccafaux/core.clj    | 70 ++++++----------------------
 src/de/mzuther/moccafaux/helpers.clj | 61 ++++++++++++++++++++++++
 3 files changed, 75 insertions(+), 58 deletions(-)
 create mode 100644 src/de/mzuther/moccafaux/helpers.clj

diff --git a/project.clj b/project.clj
index 7494377..a211d52 100644
--- a/project.clj
+++ b/project.clj
@@ -1,4 +1,4 @@
-(defproject de.mzuther/moccafaux.core "1.1.0"
+(defproject de.mzuther/moccafaux.core "1.1.1-SNAPSHOT"
   :description "Adapt power management to changes in the environment."
   :url "https://github.com/mzuther/moccafaux"
   :license {:name "EPL-2.0 OR GPL-2.0-or-later WITH Classpath-exception-2.0"
diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index 8cfc434..5d0190f 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -1,20 +1,19 @@
 (ns de.mzuther.moccafaux.core
-  (:require [clojure.data.json :as json]
+  (:require [de.mzuther.moccafaux.helpers :as helpers]
+            [clojure.data.json :as json]
             [clojure.java.io :as io]
-            [clojure.string :as string]
             [chime.core :as chime]
             [com.rpl.specter :as sp]
-            [popen]
-            [trptcolin.versioneer.core :as version])
+            [popen])
   (:gen-class))
 
 
 (def preferences
   (try (let [;; "io/file" takes care of line separators
-             file-name     (io/file (System/getProperty "user.home")
-                                    ".config" "moccafaux" "config.json")
-             user-prefs    (json/read-str (slurp file-name)
-                                          :key-fn keyword)]
+             file-name  (io/file (System/getProperty "user.home")
+                                 ".config" "moccafaux" "config.json")
+             user-prefs (json/read-str (slurp file-name)
+                                       :key-fn keyword)]
          (if (map? user-prefs)
            user-prefs
            (throw (Exception. "JSON error (not handled by library)"))))
@@ -36,49 +35,6 @@
 (def task-states (ref {}))
 
 
-(def page-width 80)
-
-
-(defn- printfln
-  "Print formatted output, as per format, followed by (newline)."
-  [fmt & args]
-  (println (apply format fmt args)))
-
-
-(defn- fill-string
-  "Create a string by n repetitions of ch.
-
-  Return this string."
-  [n ch]
-  (->> ch
-       (repeat n)
-       (apply str)))
-
-
-(defn- print-header
-  "Print a nicely formatted header with application name and version number."
-  []
-  (let [add-borders  (fn [s char] (string/join [char s char]))
-
-        header       (str "MoccaFaux v" (version/get-version "de.mzuther" "moccafaux.core"))
-
-        page-width   (- page-width 2)
-        header-width (count header)
-        left-margin  (quot (- page-width header-width) 2)
-        right-margin (- page-width header-width left-margin)
-
-        full-line    (add-borders (fill-string page-width "-") "o")
-        full-header  (add-borders
-                       (string/join [(fill-string left-margin " ")
-                                     header
-                                     (fill-string right-margin " ")])
-                       "|")]
-    (println)
-    (println full-line)
-    (println full-header)
-    (println full-line)))
-
-
 (defn- shell-exec
   "Execute command in a shell compatible to the Bourne shell and
   fork process if fork? is true.
@@ -154,12 +110,12 @@
         message   (sp/select-one [:message] prefs)]
     (when command
       (println)
-      (printfln "[%s]  Task:    %s" timestamp (name task))
-      (printfln "%s  State:   %s (%s)" padding (name new-state) message)
-      (printfln "%s  Command: %s" padding command)
+      (helpers/printfln "[%s]  Task:    %s" timestamp (name task))
+      (helpers/printfln "%s  State:   %s (%s)" padding (name new-state) message)
+      (helpers/printfln "%s  Command: %s" padding command)
       ;; execute command (finally)
       (let [exit-state (shell-exec command fork?)]
-        (printfln "%s  Result:  %s" padding (name exit-state))
+        (helpers/printfln "%s  Result:  %s" padding (name exit-state))
         exit-state))))
 
 
@@ -210,7 +166,7 @@
       (update-task task))
     (when update-needed?
       (newline)
-      (println (fill-string page-width \-)))
+      (helpers/print-line \-))
     (dosync (ref-set task-states
                      new-task-states))))
 
@@ -238,7 +194,7 @@
 (defn -main
   "Print information on application and schedule watchers."
   [& _]
-  (print-header)
+  (helpers/print-header)
 
   (start-scheduler update-status
                    (sp/select-one [:scheduler :probing-interval] preferences)))
diff --git a/src/de/mzuther/moccafaux/helpers.clj b/src/de/mzuther/moccafaux/helpers.clj
new file mode 100644
index 0000000..0b79ccc
--- /dev/null
+++ b/src/de/mzuther/moccafaux/helpers.clj
@@ -0,0 +1,61 @@
+(ns de.mzuther.moccafaux.helpers
+  (:require [clojure.string :as string]
+            [trptcolin.versioneer.core :as version]))
+
+
+(def page-width 80)
+
+
+(defn printfln
+  "Print formatted output, as per format, followed by (newline)."
+  [fmt & args]
+  (println (apply format fmt args)))
+
+
+(defn fill-string
+  "Create a string by n repetitions of ch.
+
+  Return this string."
+  [n ch]
+  (->> ch
+       (repeat n)
+       (apply str)))
+
+
+(defn add-borders
+  "Create a string consisting of ch followed by s followed by ch."
+  [s ch]
+  (string/join [ch s ch]))
+
+
+(defn print-line
+  "Print a simple line of length \"page-width\" by repeating ch,
+  followed by (newline).  If border-ch is given, change the first and
+  last occurrence of ch to it."
+  ([ch]
+   (println (-> page-width
+                (fill-string ch))))
+  ([ch border-ch]
+   (println (-> (- page-width 2)
+                (fill-string ch)
+                (add-borders border-ch)))))
+
+
+(defn print-header
+  "Print a nicely formatted header with application name and version
+  number."
+  []
+  (let [raw-header   (str "MoccaFaux v" (version/get-version "de.mzuther"
+                                                             "moccafaux.core"))
+        header-width (count raw-header)
+        left-margin  (quot (- page-width 2 header-width) 2)
+        right-margin (- page-width 2 header-width left-margin)
+
+        pre-header   (string/join [(fill-string left-margin \space)
+                                   raw-header
+                                   (fill-string right-margin \space)])
+        full-header  (add-borders pre-header \|)]
+    (println)
+    (print-line \- \o)
+    (println full-header)
+    (print-line \- \o)))

From 4cd97d370ea9a1466d8bd61e22581f886c37a38e Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Tue, 23 Jun 2020 23:00:37 +0200
Subject: [PATCH 02/19] print header when JSON parser throws an exception

---
 src/de/mzuther/moccafaux/core.clj | 1 +
 1 file changed, 1 insertion(+)

diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index 5d0190f..62c5cbe 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -18,6 +18,7 @@
            user-prefs
            (throw (Exception. "JSON error (not handled by library)"))))
        (catch Throwable e
+         (helpers/print-header)
          (newline)
          (println (str e))
          (newline)

From 88856fb7d016ae3d6e59174b6371fee180d22bb5 Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Wed, 24 Jun 2020 10:23:10 +0200
Subject: [PATCH 03/19] test "enable-disable-or-nil?"

---
 src/de/mzuther/moccafaux/core.clj |  2 +-
 test/moccafaux/core_test.clj      | 33 ++++++++++++++++++++++++++++---
 2 files changed, 31 insertions(+), 4 deletions(-)

diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index 62c5cbe..0b6ec24 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -120,7 +120,7 @@
         exit-state))))
 
 
-(defn- enable-disable-or-nil?
+(defn enable-disable-or-nil?
   "Reduce coll to a scalar.
 
   Return :disable if coll contains a :disable value.  If it doesn't
diff --git a/test/moccafaux/core_test.clj b/test/moccafaux/core_test.clj
index 2530cbe..df9d0a2 100644
--- a/test/moccafaux/core_test.clj
+++ b/test/moccafaux/core_test.clj
@@ -1,7 +1,34 @@
 (ns moccafaux.core-test
   (:require [clojure.test :refer :all]
-            [moccafaux.core :refer :all]))
+            [de.mzuther.moccafaux.core :refer :all]))
 
-(deftest a-test
+
+(deftest test-enable-disable-or-nil
   (testing "FIXME, I fail."
-    (is (= 0 1))))
+    ;; empty vector
+    (is (= (enable-disable-or-nil? [])
+           nil))
+    ;; vector of nils
+    (is (= (enable-disable-or-nil? [nil nil nil nil nil nil])
+           nil))
+    ;; vector with single :disable
+    (is (= (enable-disable-or-nil? [:disable])
+           :disable))
+    ;; vector with multiple :disable
+    (is (= (enable-disable-or-nil? [:disable :disable :disable :disable])
+           :disable))
+    ;; mixed vector with :disable
+    (is (= (enable-disable-or-nil? [nil 1 2 0 :enable :disable])
+           :disable))
+    ;; vector with single :enable
+    (is (= (enable-disable-or-nil? [:enable])
+           :enable))
+    ;; "disable" string instead of keyword
+    (is (= (enable-disable-or-nil? ["disable"])
+           :enable))
+    ;; vector with inrelated scalar value
+    (is (= (enable-disable-or-nil? [1])
+           :enable))
+    ;; mixed vector with "disable" string instead of keyword
+    (is (= (enable-disable-or-nil? [nil 1 2 0 :enable "disable"])
+           :enable))))

From 0482c68e3e4ff844e4e1ca1aa471057927a5930f Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Wed, 24 Jun 2020 10:30:32 +0200
Subject: [PATCH 04/19] return process object from "shell-exec"

---
 project.clj                       |  2 +-
 src/de/mzuther/moccafaux/core.clj | 15 ++++++++-------
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/project.clj b/project.clj
index a211d52..3d843d4 100644
--- a/project.clj
+++ b/project.clj
@@ -1,4 +1,4 @@
-(defproject de.mzuther/moccafaux.core "1.1.1-SNAPSHOT"
+(defproject de.mzuther/moccafaux.core "1.1.2-SNAPSHOT"
   :description "Adapt power management to changes in the environment."
   :url "https://github.com/mzuther/moccafaux"
   :license {:name "EPL-2.0 OR GPL-2.0-or-later WITH Classpath-exception-2.0"
diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index 0b6ec24..3d8420b 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -40,21 +40,22 @@
   "Execute command in a shell compatible to the Bourne shell and
   fork process if fork? is true.
 
-  Return :forked if command has forked, :success if command has
+  Return a vector of a keyword and the created process object.  The
+  keyword is :forked if command has forked, :success if command has
   exited with a zero exit code, and :failed in any other case."
   [command fork?]
   (let [new-process (popen/popen ["sh" "-c" command])]
     (if-not fork?
       (if (zero? (popen/exit-code new-process))
-        :success
-        :failed)
+        [:success new-process]
+        [:failed new-process])
       (do
         ;; wait for 10 ms to check whether the process is actually
         ;; created and running
         (Thread/sleep 10)
         (if (popen/running? new-process)
-          :forked
-          :failed)))))
+          [:forked new-process]
+          [:failed new-process])))))
 
 
 (defn- watch-exec
@@ -74,7 +75,7 @@
   they do not find any matching lines or processes."
   [[watch-name {:keys [enabled command tasks]}]]
   (let [save-energy? (when enabled
-                       (let [exit-state (shell-exec command false)]
+                       (let [[exit-state _] (shell-exec command false)]
                          (if (= exit-state :failed)
                            :enable
                            :disable)))]
@@ -115,7 +116,7 @@
       (helpers/printfln "%s  State:   %s (%s)" padding (name new-state) message)
       (helpers/printfln "%s  Command: %s" padding command)
       ;; execute command (finally)
-      (let [exit-state (shell-exec command fork?)]
+      (let [[exit-state _] (shell-exec command fork?)]
         (helpers/printfln "%s  Result:  %s" padding (name exit-state))
         exit-state))))
 

From 883695d820ddb81f8c6d0b42ded674440ed512e6 Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Wed, 24 Jun 2020 10:59:10 +0200
Subject: [PATCH 05/19] improve console logging

---
 src/de/mzuther/moccafaux/core.clj    | 31 +++++++++++++++++-----------
 src/de/mzuther/moccafaux/helpers.clj | 11 ++++++++++
 2 files changed, 30 insertions(+), 12 deletions(-)

diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index 3d8420b..24b15e0 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -2,6 +2,7 @@
   (:require [de.mzuther.moccafaux.helpers :as helpers]
             [clojure.data.json :as json]
             [clojure.java.io :as io]
+            [clojure.string :as string]
             [chime.core :as chime]
             [com.rpl.specter :as sp]
             [popen])
@@ -101,23 +102,22 @@
   (when (nil? new-state)
     (throw (IllegalArgumentException.
              "eeek, a NIL entered \"update-energy-saving\"")))
-  (let [timestamp (. (java.time.format.DateTimeFormatter/ofPattern "HH:mm:ss")
-                     format
-                     (java.time.LocalTime/now))
-        padding   "          "
-
-        prefs     (sp/select-one [:tasks task new-state] preferences)
+  (let [prefs     (sp/select-one [:tasks task new-state] preferences)
         command   (sp/select-one [:command] prefs)
         fork?     (sp/select-one [:fork] prefs)
         message   (sp/select-one [:message] prefs)]
     (when command
       (println)
-      (helpers/printfln "[%s]  Task:    %s" timestamp (name task))
-      (helpers/printfln "%s  State:   %s (%s)" padding (name new-state) message)
-      (helpers/printfln "%s  Command: %s" padding command)
+      (helpers/printfln "[%s]  Task:     %s %s"
+                        (helpers/get-timestamp) (name new-state) (name task))
+      (helpers/printfln "%s  State:    %s"
+                        helpers/padding message)
+      (helpers/printfln "%s  Command:  %s"
+                        helpers/padding command)
       ;; execute command (finally)
       (let [[exit-state _] (shell-exec command fork?)]
-        (helpers/printfln "%s  Result:  %s" padding (name exit-state))
+        (helpers/printfln "%s  Result:   %s"
+                          helpers/padding (name exit-state))
         exit-state))))
 
 
@@ -198,5 +198,12 @@
   [& _]
   (helpers/print-header)
 
-  (start-scheduler update-status
-                   (sp/select-one [:scheduler :probing-interval] preferences)))
+  (let [interval  (sp/select-one [:scheduler :probing-interval] preferences)]
+    (println)
+    (helpers/printfln "[%s]  Interval: %s seconds"
+                      (helpers/get-timestamp) interval)
+    (helpers/printfln "%s  Tasks:    %s"
+                      helpers/padding
+                      (string/join ", " (map name defined-tasks)))
+
+    (start-scheduler update-status interval)))
diff --git a/src/de/mzuther/moccafaux/helpers.clj b/src/de/mzuther/moccafaux/helpers.clj
index 0b79ccc..ff88601 100644
--- a/src/de/mzuther/moccafaux/helpers.clj
+++ b/src/de/mzuther/moccafaux/helpers.clj
@@ -4,6 +4,7 @@
 
 
 (def page-width 80)
+(def padding   "          ")
 
 
 (defn printfln
@@ -22,6 +23,16 @@
        (apply str)))
 
 
+(defn get-timestamp
+  "Get current local time.
+
+  Return a string formatted as \"HH:mm:ss\"."
+  []
+  (. (java.time.format.DateTimeFormatter/ofPattern "HH:mm:ss")
+     format
+     (java.time.LocalTime/now)))
+
+
 (defn add-borders
   "Create a string consisting of ch followed by s followed by ch."
   [s ch]

From b447ac7f80f84de24fa06dacb6abf27f9645b613 Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Wed, 24 Jun 2020 11:31:31 +0200
Subject: [PATCH 06/19] display watch names on console log

---
 src/de/mzuther/moccafaux/core.clj    | 35 +++++++++++++++++++++-------
 src/de/mzuther/moccafaux/helpers.clj |  8 +++----
 2 files changed, 30 insertions(+), 13 deletions(-)

diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index 24b15e0..108f204 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -27,12 +27,22 @@
          (System/exit 1))))
 
 
-(def defined-tasks
+(def task-names
   (->> preferences
        (sp/select [:tasks sp/MAP-KEYS])
        sort))
 
 
+(def defined-watches
+  (->> preferences
+       (sp/select-one [:watches])
+       sort))
+
+
+(def watch-names
+  (sp/select [sp/MAP-KEYS] defined-watches))
+
+
 ;; empty ref forces an update on first call to "update-status"
 (def task-states (ref {}))
 
@@ -88,7 +98,7 @@
                      (when (get tasks task)
                        save-energy?)))
             {:watch watch-name}
-            defined-tasks)))
+            task-names)))
 
 
 (defn update-energy-saving
@@ -108,7 +118,7 @@
         message   (sp/select-one [:message] prefs)]
     (when command
       (println)
-      (helpers/printfln "[%s]  Task:     %s %s"
+      (helpers/printfln "%s  Task:     %s %s"
                         (helpers/get-timestamp) (name new-state) (name task))
       (helpers/printfln "%s  State:    %s"
                         helpers/padding message)
@@ -149,7 +159,7 @@
   Return new task states, consisting of a map containing keys for all
   defined tasks with values according to \"enable-disable-or-nil?\"."
   [_]
-  (let [exit-states     (->> (sp/select-one [:watches] preferences)
+  (let [exit-states     (->> defined-watches
                              (map watch-exec))
         new-task-states (reduce (fn [new-ts task]
                                   (assoc new-ts
@@ -157,14 +167,14 @@
                                          (enable-disable-or-nil?
                                            (map task exit-states))))
                                 {}
-                                defined-tasks)
+                                task-names)
         update-needed?  (not= new-task-states @task-states)
         update-task     (fn [task]
                           (let [new-state (sp/select-one [task] new-task-states)
                                 old-state (sp/select-one [task] @task-states)]
                             (when (not= new-state old-state)
                               (update-energy-saving task new-state))))]
-    (doseq [task defined-tasks]
+    (doseq [task task-names]
       (update-task task))
     (when update-needed?
       (newline)
@@ -200,10 +210,17 @@
 
   (let [interval  (sp/select-one [:scheduler :probing-interval] preferences)]
     (println)
-    (helpers/printfln "[%s]  Interval: %s seconds"
-                      (helpers/get-timestamp) interval)
+    (helpers/printfln "%s  Probe:    every %s seconds"
+                      (helpers/get-timestamp)
+                      interval)
     (helpers/printfln "%s  Tasks:    %s"
                       helpers/padding
-                      (string/join ", " (map name defined-tasks)))
+                      (string/join ", " (map name task-names)))
+    (helpers/printfln "%s  Watches:  %s"
+                      helpers/padding
+                      (string/join ", " (map name watch-names)))
+
+    (newline)
+    (helpers/print-line \-)
 
     (start-scheduler update-status interval)))
diff --git a/src/de/mzuther/moccafaux/helpers.clj b/src/de/mzuther/moccafaux/helpers.clj
index ff88601..7e70c77 100644
--- a/src/de/mzuther/moccafaux/helpers.clj
+++ b/src/de/mzuther/moccafaux/helpers.clj
@@ -26,11 +26,11 @@
 (defn get-timestamp
   "Get current local time.
 
-  Return a string formatted as \"HH:mm:ss\"."
+  Return a string formatted as \"[HH:mm:ss]\"."
   []
-  (. (java.time.format.DateTimeFormatter/ofPattern "HH:mm:ss")
-     format
-     (java.time.LocalTime/now)))
+  (->> (java.time.LocalTime/now)
+       (.format (java.time.format.DateTimeFormatter/ofPattern "HH:mm:ss"))
+       (format "[%s]")))
 
 
 (defn add-borders

From dcdad0cf678664afbb869bb8ece20cfa2b5ccccf Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Thu, 25 Jun 2020 22:54:44 +0200
Subject: [PATCH 07/19] improve settings display on console log

---
 src/de/mzuther/moccafaux/core.clj    | 14 ++----------
 src/de/mzuther/moccafaux/helpers.clj | 33 +++++++++++++++++++++++++++-
 2 files changed, 34 insertions(+), 13 deletions(-)

diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index 108f204..722b6f3 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -2,7 +2,6 @@
   (:require [de.mzuther.moccafaux.helpers :as helpers]
             [clojure.data.json :as json]
             [clojure.java.io :as io]
-            [clojure.string :as string]
             [chime.core :as chime]
             [com.rpl.specter :as sp]
             [popen])
@@ -117,7 +116,7 @@
         fork?     (sp/select-one [:fork] prefs)
         message   (sp/select-one [:message] prefs)]
     (when command
-      (println)
+      (newline)
       (helpers/printfln "%s  Task:     %s %s"
                         (helpers/get-timestamp) (name new-state) (name task))
       (helpers/printfln "%s  State:    %s"
@@ -209,16 +208,7 @@
   (helpers/print-header)
 
   (let [interval  (sp/select-one [:scheduler :probing-interval] preferences)]
-    (println)
-    (helpers/printfln "%s  Probe:    every %s seconds"
-                      (helpers/get-timestamp)
-                      interval)
-    (helpers/printfln "%s  Tasks:    %s"
-                      helpers/padding
-                      (string/join ", " (map name task-names)))
-    (helpers/printfln "%s  Watches:  %s"
-                      helpers/padding
-                      (string/join ", " (map name watch-names)))
+    (helpers/print-settings interval task-names watch-names)
 
     (newline)
     (helpers/print-line \-)
diff --git a/src/de/mzuther/moccafaux/helpers.clj b/src/de/mzuther/moccafaux/helpers.clj
index 7e70c77..c51b4b6 100644
--- a/src/de/mzuther/moccafaux/helpers.clj
+++ b/src/de/mzuther/moccafaux/helpers.clj
@@ -66,7 +66,38 @@
                                    raw-header
                                    (fill-string right-margin \space)])
         full-header  (add-borders pre-header \|)]
-    (println)
+    (newline)
     (print-line \- \o)
     (println full-header)
     (print-line \- \o)))
+
+
+(defn print-list
+  "Print coll as a list with the first element prepended by
+  padding-first (probably containing an annotation) and the remaining
+  elements by padding-rest (usually just white space).  The respective
+  padding and element will be spaced by sep and a single space. "
+  [padding-first padding-rest sep coll]
+  (let [paddings  (concat [padding-first]
+                          (repeat padding-rest))
+        separator (str sep " ")]
+    ;; mapv is not lazy!
+    (mapv #(println (string/join separator [%1 %2]))
+          paddings
+          coll)))
+
+
+(defn print-settings
+  "Print settings using a nice layout."
+  [interval task-names watch-names]
+  (let [padding-tasks   (format "%s  Tasks:    " padding)
+        padding-watches (format "%s  Watches:  " padding)
+        padding-rest    (format "%s            " padding)]
+    (newline)
+    (printfln "%s  Probe:    every %s seconds"
+              (get-timestamp)
+              interval)
+    (print-list padding-tasks padding-rest "-"
+                (map name task-names))
+    (print-list padding-watches padding-rest "-"
+                (map name watch-names))))

From e4577b988cdd88acc37ab9ff02d2f9d211321dc4 Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Sun, 5 Jul 2020 18:57:25 +0200
Subject: [PATCH 08/19] spec functions

---
 config-SAMPLE.json                   |  4 +-
 project.clj                          |  2 +-
 src/de/mzuther/moccafaux/core.clj    | 15 ++++-
 src/de/mzuther/moccafaux/helpers.clj | 13 +++-
 src/de/mzuther/moccafaux/spec.clj    | 93 ++++++++++++++++++++++++++++
 5 files changed, 122 insertions(+), 5 deletions(-)
 create mode 100644 src/de/mzuther/moccafaux/spec.clj

diff --git a/config-SAMPLE.json b/config-SAMPLE.json
index 910f099..a758eaa 100644
--- a/config-SAMPLE.json
+++ b/config-SAMPLE.json
@@ -7,7 +7,7 @@
     "sleep": {
       "enable": {
         "message": "allow computer to save energy",
-        "command": "xautolock -time 15 -locker 'systemctl suspend' -detectsleep",
+        "command": "xautolock -time 10 -locker 'systemctl suspend' -detectsleep",
         "fork":    true
       },
       "disable": {
@@ -20,7 +20,7 @@
     "dpms": {
       "enable": {
         "message": "allow screen to save energy",
-        "command": "xset dpms 300 600 900",
+        "command": "xset dpms 0 300 600",
         "fork":    false
       },
       "disable": {
diff --git a/project.clj b/project.clj
index 3d843d4..d815f52 100644
--- a/project.clj
+++ b/project.clj
@@ -1,4 +1,4 @@
-(defproject de.mzuther/moccafaux.core "1.1.2-SNAPSHOT"
+(defproject de.mzuther/moccafaux.core "1.1.3-SNAPSHOT"
   :description "Adapt power management to changes in the environment."
   :url "https://github.com/mzuther/moccafaux"
   :license {:name "EPL-2.0 OR GPL-2.0-or-later WITH Classpath-exception-2.0"
diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index 722b6f3..13e502d 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -204,9 +204,22 @@
 
 (defn -main
   "Print information on application and schedule watchers."
-  [& _]
+  [& args]
   (helpers/print-header)
 
+  ;; display help and exit
+  (when (some #{"help" "--help"} args)
+    (newline)
+    (println "Usage: MoccaFaux [--debug] [--help]")
+    (newline)
+    (flush)
+    (System/exit 0))
+
+  ;; enable debug mode (so far, this only instruments specs)
+  (when (some #{"debug" "--debug"} args)
+    (helpers/instrument-specs))
+
+  ;; display settings and enter main loop
   (let [interval  (sp/select-one [:scheduler :probing-interval] preferences)]
     (helpers/print-settings interval task-names watch-names)
 
diff --git a/src/de/mzuther/moccafaux/helpers.clj b/src/de/mzuther/moccafaux/helpers.clj
index c51b4b6..3629044 100644
--- a/src/de/mzuther/moccafaux/helpers.clj
+++ b/src/de/mzuther/moccafaux/helpers.clj
@@ -1,5 +1,6 @@
 (ns de.mzuther.moccafaux.helpers
-  (:require [clojure.string :as string]
+  (:require [de.mzuther.moccafaux.spec :as spec]
+            [clojure.string :as string]
             [trptcolin.versioneer.core :as version]))
 
 
@@ -97,7 +98,17 @@
     (printfln "%s  Probe:    every %s seconds"
               (get-timestamp)
               interval)
+    (newline)
     (print-list padding-tasks padding-rest "-"
                 (map name task-names))
+    (newline)
     (print-list padding-watches padding-rest "-"
                 (map name watch-names))))
+
+
+(defn instrument-specs []
+  (let [padding-first (format "%s  Specs:    " (get-timestamp))
+        padding-rest  (format "%s            " padding)]
+    (newline)
+    (print-list padding-first padding-rest "-"
+                (sort (spec/instrument-specs)))))
diff --git a/src/de/mzuther/moccafaux/spec.clj b/src/de/mzuther/moccafaux/spec.clj
new file mode 100644
index 0000000..f0cfa19
--- /dev/null
+++ b/src/de/mzuther/moccafaux/spec.clj
@@ -0,0 +1,93 @@
+;; resolve circular dependency
+(ns de.mzuther.moccafaux.core)
+
+(ns de.mzuther.moccafaux.spec
+  (:require  [de.mzuther.moccafaux.core]
+             [clojure.spec.alpha :as s]
+             [clojure.spec.test.alpha :as stest]))
+
+
+(s/def ::enabled
+  boolean?)
+
+(s/def ::interval
+  (s/and
+    int?
+    pos?))
+
+(s/def ::command
+  (s/and
+    string?
+    #(pos? (count %))))
+
+(s/def ::tasks
+  (s/map-of keyword? boolean?))
+
+(s/def ::task-states
+  (s/coll-of (s/cat :name string?
+                    :state (s/* ::task-state))))
+
+(s/def ::exit-code
+  #{:success :forked :failed})
+
+(s/def ::task-state
+  (s/nilable
+    #{:enable :disable}))
+
+(s/def ::task-state-coll
+  (s/coll-of ::task-state))
+
+(s/def ::watch
+  (s/cat :name keyword?
+         :settings (s/keys :req-un [::enabled
+                                    ::command
+                                    ::tasks])))
+
+;; -----------------------------------------------------------------------------
+
+(s/def ::shell-exec-fn
+  (fn [{:keys [args ret]}]
+    (if (get args :fork?)
+      (contains? #{:forked :failed} ret)
+      (contains? #{:success :failed} ret))))
+
+(s/fdef de.mzuther.moccafaux.core/shell-exec
+  :args (s/cat :command ::command
+               :fork? boolean?)
+  :ret  ::exit-code
+  :fn   ::shell-exec-fn)
+
+;; -----------------------------------------------------------------------------
+
+(s/fdef de.mzuther.moccafaux.core/watch-exec
+  :args (s/cat :watch ::watch)
+  :ret  ::task-states)
+
+
+(s/fdef de.mzuther.moccafaux.core/update-energy-saving
+  :args (s/cat :task keyword?
+               :state ::task-state)
+  :ret  ::exit-code)
+
+
+(s/fdef de.mzuther.moccafaux.core/enable-disable-or-nil?
+  :args (s/cat :task-states ::task-state-coll)
+  :ret  ::task-state)
+
+
+(s/fdef de.mzuther.moccafaux.core/update-status
+  :args (s/cat :timestamp-ignored any?)
+  :ret  ::task-states)
+
+
+(s/fdef de.mzuther.moccafaux.core/start-scheduler
+  :args (s/cat :schedule-fn fn?
+               :interval ::interval)
+  :ret  (s/coll-of (s/cat :name string?
+                          :state (s/* ::task-state))))
+
+;; -----------------------------------------------------------------------------
+
+(defn instrument-specs []
+  (stest/instrument (stest/enumerate-namespace
+                      'de.mzuther.moccafaux.core)))

From 64d2776f1bec3e9392d7b8ad5b7a26ca519451ff Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Sun, 5 Jul 2020 20:12:32 +0200
Subject: [PATCH 09/19] parse command line parameters

---
 project.clj                          |  1 +
 src/de/mzuther/moccafaux/core.clj    | 44 +++++++++++++++++-----------
 src/de/mzuther/moccafaux/helpers.clj | 20 +++++++++++++
 3 files changed, 48 insertions(+), 17 deletions(-)

diff --git a/project.clj b/project.clj
index d815f52..b4fe919 100644
--- a/project.clj
+++ b/project.clj
@@ -6,6 +6,7 @@
 
   :dependencies [[org.clojure/clojure "1.10.1"]
                  [org.clojure/data.json "1.0.0"]
+                 [org.clojure/tools.cli "1.0.194"]
                  [com.rpl/specter "1.1.3"]
                  [jarohen/chime "0.3.2"]
                  [popen "0.3.1"]
diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index 13e502d..d9edb36 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -1,5 +1,6 @@
 (ns de.mzuther.moccafaux.core
   (:require [de.mzuther.moccafaux.helpers :as helpers]
+            [clojure.tools.cli :as cli]
             [clojure.data.json :as json]
             [clojure.java.io :as io]
             [chime.core :as chime]
@@ -8,6 +9,13 @@
   (:gen-class))
 
 
+(def cli-options
+  [["-d" "--debug"
+    :desc "instrument function specs"]
+   ["-h" "--help"
+    :desc "display version and usage information"]])
+
+
 (def preferences
   (try (let [;; "io/file" takes care of line separators
              file-name  (io/file (System/getProperty "user.home")
@@ -204,26 +212,28 @@
 
 (defn -main
   "Print information on application and schedule watchers."
-  [& args]
+  [& unparsed-args]
   (helpers/print-header)
 
-  ;; display help and exit
-  (when (some #{"help" "--help"} args)
-    (newline)
-    (println "Usage: MoccaFaux [--debug] [--help]")
-    (newline)
-    (flush)
-    (System/exit 0))
+  (let [args (cli/parse-opts unparsed-args cli-options)]
+    (cond
+      ;; display errors and exit
+      (sp/select-one [:errors] args)
+        (helpers/exit-after-printing-help-and-errors args 2)
 
-  ;; enable debug mode (so far, this only instruments specs)
-  (when (some #{"debug" "--debug"} args)
-    (helpers/instrument-specs))
+      ;; display help and exit
+      (sp/select-one [:options :help] args)
+        (helpers/exit-after-printing-help-and-errors args 0))
 
-  ;; display settings and enter main loop
-  (let [interval  (sp/select-one [:scheduler :probing-interval] preferences)]
-    (helpers/print-settings interval task-names watch-names)
+    ;; enable debug mode (so far, this only instruments specs)
+    (when (sp/select-one [:options :debug] args)
+      (helpers/instrument-specs))
 
-    (newline)
-    (helpers/print-line \-)
+    ;; display settings and enter main loop
+    (let [interval (sp/select-one [:scheduler :probing-interval] preferences)]
+      (helpers/print-settings interval task-names watch-names)
+
+      (newline)
+      (helpers/print-line \-)
 
-    (start-scheduler update-status interval)))
+      (start-scheduler update-status interval))))
diff --git a/src/de/mzuther/moccafaux/helpers.clj b/src/de/mzuther/moccafaux/helpers.clj
index 3629044..de7f5f9 100644
--- a/src/de/mzuther/moccafaux/helpers.clj
+++ b/src/de/mzuther/moccafaux/helpers.clj
@@ -88,6 +88,26 @@
           coll)))
 
 
+(defn exit-after-printing-help-and-errors
+  "Print help, command line parsing errors (if any) and exit with
+  given exit-code."
+  [args exit-code]
+  (let [{:keys [summary errors]} args]
+    (when errors
+      (newline)
+      (doseq [error errors]
+        (println "Error:" error)))
+
+    (newline)
+    (println "Usage: java -jar moccafaux.jar [OPTION...]")
+    (newline)
+    ;; display command line help
+    (println summary)
+    (newline)
+    (flush)
+    (System/exit exit-code)))
+
+
 (defn print-settings
   "Print settings using a nice layout."
   [interval task-names watch-names]

From fa6910b818d0e9f82b16764d16354e0c700f2473 Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Mon, 6 Jul 2020 09:39:22 +0200
Subject: [PATCH 10/19] use records to improve reading of code

---
 src/de/mzuther/moccafaux/core.clj | 58 +++++++++++++++++++++----------
 src/de/mzuther/moccafaux/spec.clj | 12 +++----
 2 files changed, 45 insertions(+), 25 deletions(-)

diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index d9edb36..43f1303 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -1,8 +1,9 @@
 (ns de.mzuther.moccafaux.core
   (:require [de.mzuther.moccafaux.helpers :as helpers]
-            [clojure.tools.cli :as cli]
             [clojure.data.json :as json]
             [clojure.java.io :as io]
+            [clojure.string :as string]
+            [clojure.tools.cli :as cli]
             [chime.core :as chime]
             [com.rpl.specter :as sp]
             [popen])
@@ -54,6 +55,31 @@
 (def task-states (ref {}))
 
 
+(defrecord TaskStates [id states]
+  Object
+  (toString [this]
+    (let [id (name (get this :id))]
+      (str id ": " (string/join ", " states)))))
+
+
+(defrecord TaskState [id state]
+  Object
+  (toString [this]
+    (let [id    (name (get this :id))
+          state (if-let [state (get this :state)]
+                  (name state)
+                  "nil")]
+      (str id "=" state))))
+
+
+(defn make-task-states [id states]
+  (TaskStates. id states))
+
+
+(defn make-task-state [id state]
+  (TaskState. id state))
+
+
 (defn- shell-exec
   "Execute command in a shell compatible to the Bourne shell and
   fork process if fork? is true.
@@ -97,15 +123,14 @@
                          (if (= exit-state :failed)
                            :enable
                            :disable)))]
-    ;; Apply exit state of watch to all defined tasks (or nil when the
+    ;; apply exit state of watch to all defined tasks (or nil when the
     ;; watch has not been assigned to the given task).
-    (reduce (fn [exit-states task]
-              (assoc exit-states
-                     task
-                     (when (get tasks task)
-                       save-energy?)))
-            {:watch watch-name}
-            task-names)))
+    (make-task-states watch-name
+                      (map (fn [task]
+                             (make-task-state task
+                                              (when (get tasks task)
+                                                save-energy?)))
+                           task-names))))
 
 
 (defn update-energy-saving
@@ -166,15 +191,12 @@
   Return new task states, consisting of a map containing keys for all
   defined tasks with values according to \"enable-disable-or-nil?\"."
   [_]
-  (let [exit-states     (->> defined-watches
-                             (map watch-exec))
-        new-task-states (reduce (fn [new-ts task]
-                                  (assoc new-ts
-                                         task
-                                         (enable-disable-or-nil?
-                                           (map task exit-states))))
-                                {}
-                                task-names)
+  (let [exit-states     (map watch-exec defined-watches)
+        extract-state   (fn [task] (->> exit-states
+                                        (sp/select [sp/ALL :states sp/ALL #(= (:id %) task) :state])
+                                        (enable-disable-or-nil?)
+                                        (vector task)))
+        new-task-states (into {} (map extract-state task-names))
         update-needed?  (not= new-task-states @task-states)
         update-task     (fn [task]
                           (let [new-state (sp/select-one [task] new-task-states)
diff --git a/src/de/mzuther/moccafaux/spec.clj b/src/de/mzuther/moccafaux/spec.clj
index f0cfa19..55607c5 100644
--- a/src/de/mzuther/moccafaux/spec.clj
+++ b/src/de/mzuther/moccafaux/spec.clj
@@ -2,9 +2,9 @@
 (ns de.mzuther.moccafaux.core)
 
 (ns de.mzuther.moccafaux.spec
-  (:require  [de.mzuther.moccafaux.core]
-             [clojure.spec.alpha :as s]
-             [clojure.spec.test.alpha :as stest]))
+  (:require [de.mzuther.moccafaux.core]
+            [clojure.spec.alpha :as s]
+            [clojure.spec.test.alpha :as stest]))
 
 
 (s/def ::enabled
@@ -38,10 +38,8 @@
   (s/coll-of ::task-state))
 
 (s/def ::watch
-  (s/cat :name keyword?
-         :settings (s/keys :req-un [::enabled
-                                    ::command
-                                    ::tasks])))
+  ;; something seems to be broken in spec instrumentation
+  map-entry?)
 
 ;; -----------------------------------------------------------------------------
 

From 2178f45599da72781f3408663c932a56bd8aa2a1 Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Mon, 6 Jul 2020 10:33:54 +0200
Subject: [PATCH 11/19] drop specs

* it's not worth the hassle in this application ...
---
 project.clj                          |  2 +-
 src/de/mzuther/moccafaux/core.clj    |  8 +--
 src/de/mzuther/moccafaux/helpers.clj | 13 +---
 src/de/mzuther/moccafaux/spec.clj    | 91 ----------------------------
 4 files changed, 4 insertions(+), 110 deletions(-)
 delete mode 100644 src/de/mzuther/moccafaux/spec.clj

diff --git a/project.clj b/project.clj
index b4fe919..27aa715 100644
--- a/project.clj
+++ b/project.clj
@@ -1,4 +1,4 @@
-(defproject de.mzuther/moccafaux.core "1.1.3-SNAPSHOT"
+(defproject de.mzuther/moccafaux.core "1.1.4-SNAPSHOT"
   :description "Adapt power management to changes in the environment."
   :url "https://github.com/mzuther/moccafaux"
   :license {:name "EPL-2.0 OR GPL-2.0-or-later WITH Classpath-exception-2.0"
diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index 43f1303..3cc494a 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -11,9 +11,7 @@
 
 
 (def cli-options
-  [["-d" "--debug"
-    :desc "instrument function specs"]
-   ["-h" "--help"
+  [["-h" "--help"
     :desc "display version and usage information"]])
 
 
@@ -247,10 +245,6 @@
       (sp/select-one [:options :help] args)
         (helpers/exit-after-printing-help-and-errors args 0))
 
-    ;; enable debug mode (so far, this only instruments specs)
-    (when (sp/select-one [:options :debug] args)
-      (helpers/instrument-specs))
-
     ;; display settings and enter main loop
     (let [interval (sp/select-one [:scheduler :probing-interval] preferences)]
       (helpers/print-settings interval task-names watch-names)
diff --git a/src/de/mzuther/moccafaux/helpers.clj b/src/de/mzuther/moccafaux/helpers.clj
index de7f5f9..749559b 100644
--- a/src/de/mzuther/moccafaux/helpers.clj
+++ b/src/de/mzuther/moccafaux/helpers.clj
@@ -1,6 +1,5 @@
 (ns de.mzuther.moccafaux.helpers
-  (:require [de.mzuther.moccafaux.spec :as spec]
-            [clojure.string :as string]
+  (:require [clojure.string :as string]
             [trptcolin.versioneer.core :as version]))
 
 
@@ -96,7 +95,7 @@
     (when errors
       (newline)
       (doseq [error errors]
-        (println "Error:" error)))
+        (println "ERROR:" error)))
 
     (newline)
     (println "Usage: java -jar moccafaux.jar [OPTION...]")
@@ -124,11 +123,3 @@
     (newline)
     (print-list padding-watches padding-rest "-"
                 (map name watch-names))))
-
-
-(defn instrument-specs []
-  (let [padding-first (format "%s  Specs:    " (get-timestamp))
-        padding-rest  (format "%s            " padding)]
-    (newline)
-    (print-list padding-first padding-rest "-"
-                (sort (spec/instrument-specs)))))
diff --git a/src/de/mzuther/moccafaux/spec.clj b/src/de/mzuther/moccafaux/spec.clj
deleted file mode 100644
index 55607c5..0000000
--- a/src/de/mzuther/moccafaux/spec.clj
+++ /dev/null
@@ -1,91 +0,0 @@
-;; resolve circular dependency
-(ns de.mzuther.moccafaux.core)
-
-(ns de.mzuther.moccafaux.spec
-  (:require [de.mzuther.moccafaux.core]
-            [clojure.spec.alpha :as s]
-            [clojure.spec.test.alpha :as stest]))
-
-
-(s/def ::enabled
-  boolean?)
-
-(s/def ::interval
-  (s/and
-    int?
-    pos?))
-
-(s/def ::command
-  (s/and
-    string?
-    #(pos? (count %))))
-
-(s/def ::tasks
-  (s/map-of keyword? boolean?))
-
-(s/def ::task-states
-  (s/coll-of (s/cat :name string?
-                    :state (s/* ::task-state))))
-
-(s/def ::exit-code
-  #{:success :forked :failed})
-
-(s/def ::task-state
-  (s/nilable
-    #{:enable :disable}))
-
-(s/def ::task-state-coll
-  (s/coll-of ::task-state))
-
-(s/def ::watch
-  ;; something seems to be broken in spec instrumentation
-  map-entry?)
-
-;; -----------------------------------------------------------------------------
-
-(s/def ::shell-exec-fn
-  (fn [{:keys [args ret]}]
-    (if (get args :fork?)
-      (contains? #{:forked :failed} ret)
-      (contains? #{:success :failed} ret))))
-
-(s/fdef de.mzuther.moccafaux.core/shell-exec
-  :args (s/cat :command ::command
-               :fork? boolean?)
-  :ret  ::exit-code
-  :fn   ::shell-exec-fn)
-
-;; -----------------------------------------------------------------------------
-
-(s/fdef de.mzuther.moccafaux.core/watch-exec
-  :args (s/cat :watch ::watch)
-  :ret  ::task-states)
-
-
-(s/fdef de.mzuther.moccafaux.core/update-energy-saving
-  :args (s/cat :task keyword?
-               :state ::task-state)
-  :ret  ::exit-code)
-
-
-(s/fdef de.mzuther.moccafaux.core/enable-disable-or-nil?
-  :args (s/cat :task-states ::task-state-coll)
-  :ret  ::task-state)
-
-
-(s/fdef de.mzuther.moccafaux.core/update-status
-  :args (s/cat :timestamp-ignored any?)
-  :ret  ::task-states)
-
-
-(s/fdef de.mzuther.moccafaux.core/start-scheduler
-  :args (s/cat :schedule-fn fn?
-               :interval ::interval)
-  :ret  (s/coll-of (s/cat :name string?
-                          :state (s/* ::task-state))))
-
-;; -----------------------------------------------------------------------------
-
-(defn instrument-specs []
-  (stest/instrument (stest/enumerate-namespace
-                      'de.mzuther.moccafaux.core)))

From c66965f4a255d56b1483a7526b781b3fee9aae05 Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Mon, 6 Jul 2020 17:27:38 +0200
Subject: [PATCH 12/19] use records to improve reading of code (part #2)

---
 src/de/mzuther/moccafaux/core.clj | 53 +++++++++++++++++++++----------
 1 file changed, 36 insertions(+), 17 deletions(-)

diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index 3cc494a..fb79fcd 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -53,13 +53,6 @@
 (def task-states (ref {}))
 
 
-(defrecord TaskStates [id states]
-  Object
-  (toString [this]
-    (let [id (name (get this :id))]
-      (str id ": " (string/join ", " states)))))
-
-
 (defrecord TaskState [id state]
   Object
   (toString [this]
@@ -70,14 +63,40 @@
       (str id "=" state))))
 
 
-(defn make-task-states [id states]
-  (TaskStates. id states))
+(defrecord TaskStates [id states]
+  Object
+  (toString [this]
+    (let [id (name (get this :id))]
+      (str id ": " (string/join ", " states)))))
 
 
-(defn make-task-state [id state]
+(defn make-task-state
+  "Create new TaskState object with given task ID and an exit state
+  (:enabled if exit state was *non-zero*, :disabled if it was *zero*
+  and nil if the watch was either disabled or not assigned to a
+  task)."
+  [id state]
   (TaskState. id state))
 
 
+(defn make-task-states
+  "Create new TaskStates object with given ID and a TaskState seq."
+  [id states]
+  (TaskStates. id states))
+
+
+(defrecord ProcessObject [process state])
+
+
+(defn make-process-object
+  "Create new ProcessObject object consisting of a Java process object
+  and an exit state (:forked if command has forked, :success if
+  command has exited with a zero exit code, and :failed in any other
+  case)."
+  [process state]
+  (ProcessObject. process state))
+
+
 (defn- shell-exec
   "Execute command in a shell compatible to the Bourne shell and
   fork process if fork? is true.
@@ -89,15 +108,15 @@
   (let [new-process (popen/popen ["sh" "-c" command])]
     (if-not fork?
       (if (zero? (popen/exit-code new-process))
-        [:success new-process]
-        [:failed new-process])
+        (make-process-object new-process :success)
+        (make-process-object new-process :failed))
       (do
         ;; wait for 10 ms to check whether the process is actually
         ;; created and running
         (Thread/sleep 10)
         (if (popen/running? new-process)
-          [:forked new-process]
-          [:failed new-process])))))
+          (make-process-object new-process :forked)
+          (make-process-object new-process :failed))))))
 
 
 (defn- watch-exec
@@ -105,7 +124,7 @@
 
   Return a map containing the watch's name and an exit state for every
   defined task (:enabled if exit state was *non-zero*, :disabled if it
-  was *zero*).  In case a watch has not been enabled or to a given
+  was *zero*).  In case a watch has not been enabled or assigned to a
   task, set exit state to nil.
 
   Background information: energy saving is enabled when a watch is
@@ -117,7 +136,7 @@
   they do not find any matching lines or processes."
   [[watch-name {:keys [enabled command tasks]}]]
   (let [save-energy? (when enabled
-                       (let [[exit-state _] (shell-exec command false)]
+                       (let [{exit-state :state} (shell-exec command false)]
                          (if (= exit-state :failed)
                            :enable
                            :disable)))]
@@ -155,7 +174,7 @@
       (helpers/printfln "%s  Command:  %s"
                         helpers/padding command)
       ;; execute command (finally)
-      (let [[exit-state _] (shell-exec command fork?)]
+      (let [{exit-state :state} (shell-exec command fork?)]
         (helpers/printfln "%s  Result:   %s"
                           helpers/padding (name exit-state))
         exit-state))))

From a49d6a6f11e53f107c275cfe8d6a758d1d1c0147 Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Mon, 6 Jul 2020 22:26:08 +0200
Subject: [PATCH 13/19] add pre-conditions to make-... functions

---
 src/de/mzuther/moccafaux/core.clj | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index fb79fcd..6dda4cd 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -76,12 +76,17 @@
   and nil if the watch was either disabled or not assigned to a
   task)."
   [id state]
+  {:pre [(keyword? id)
+         (or (nil? state)
+             (get #{:enable :disable} state))]}
   (TaskState. id state))
 
 
 (defn make-task-states
   "Create new TaskStates object with given ID and a TaskState seq."
   [id states]
+  {:pre [(keyword? id)
+         (every? #(= (type %) TaskState) states)]}
   (TaskStates. id states))
 
 
@@ -94,6 +99,8 @@
   command has exited with a zero exit code, and :failed in any other
   case)."
   [process state]
+  {:pre [(= (type process) java.lang.ProcessImpl)
+         (get #{:forked :success :failed} state)]}
   (ProcessObject. process state))
 
 

From 6ca2edb84965066a619e43408464b50f60f091f2 Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Mon, 6 Jul 2020 22:26:27 +0200
Subject: [PATCH 14/19] fix docstrings

---
 src/de/mzuther/moccafaux/core.clj | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index 6dda4cd..2df3a0f 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -72,7 +72,7 @@
 
 (defn make-task-state
   "Create new TaskState object with given task ID and an exit state
-  (:enabled if exit state was *non-zero*, :disabled if it was *zero*
+  (:enable if exit state was *non-zero*, :disable if it was *zero*
   and nil if the watch was either disabled or not assigned to a
   task)."
   [id state]
@@ -130,7 +130,7 @@
   "Execute watch and apply exit state of watch to all defined tasks.
 
   Return a map containing the watch's name and an exit state for every
-  defined task (:enabled if exit state was *non-zero*, :disabled if it
+  defined task (:enable if exit state was *non-zero*, :disable if it
   was *zero*).  In case a watch has not been enabled or assigned to a
   task, set exit state to nil.
 

From 3de334160c0ed1e0f21bcdb070c8539b5f2ef40e Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Mon, 6 Jul 2020 23:06:57 +0200
Subject: [PATCH 15/19] improve Leiningen project

* disable assertions in uberjar

* add debug profile
---
 project.clj | 14 ++++++++++++--
 1 file changed, 12 insertions(+), 2 deletions(-)

diff --git a/project.clj b/project.clj
index 27aa715..c8a99ef 100644
--- a/project.clj
+++ b/project.clj
@@ -2,7 +2,7 @@
   :description "Adapt power management to changes in the environment."
   :url "https://github.com/mzuther/moccafaux"
   :license {:name "EPL-2.0 OR GPL-2.0-or-later WITH Classpath-exception-2.0"
-            :url "https://www.eclipse.org/legal/epl-2.0/"}
+            :url  "https://www.eclipse.org/legal/epl-2.0/"}
 
   :dependencies [[org.clojure/clojure "1.10.1"]
                  [org.clojure/data.json "1.0.0"]
@@ -16,4 +16,14 @@
   :target-path "target/%s"
   :uberjar-name "moccafaux.jar"
 
-  :profiles {:uberjar {:aot :all}})
+  :profiles {:debug   {:debug       true
+                       :injections  [(newline)
+                                     (doseq [s (into {} (System/getProperties))]
+                                       (prn s))
+                                     (newline)
+                                     (flush)]
+                       :global-vars {*warn-on-reflection* true
+                                     *assert*             true}}
+             :uberjar {:aot         :all
+                       :global-vars {*warn-on-reflection* true
+                                     *assert*             false}}})

From dff0beefb355acaa69816e1a61d68a4ceff4ccfa Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Sun, 12 Jul 2020 11:26:50 +0200
Subject: [PATCH 16/19] re-order helper functions

---
 src/de/mzuther/moccafaux/helpers.clj | 64 ++++++++++++++--------------
 1 file changed, 32 insertions(+), 32 deletions(-)

diff --git a/src/de/mzuther/moccafaux/helpers.clj b/src/de/mzuther/moccafaux/helpers.clj
index 749559b..9d4bf3e 100644
--- a/src/de/mzuther/moccafaux/helpers.clj
+++ b/src/de/mzuther/moccafaux/helpers.clj
@@ -7,10 +7,14 @@
 (def padding   "          ")
 
 
-(defn printfln
-  "Print formatted output, as per format, followed by (newline)."
-  [fmt & args]
-  (println (apply format fmt args)))
+(defn get-timestamp
+  "Get current local time.
+
+  Return a string formatted as \"[HH:mm:ss]\"."
+  []
+  (->> (java.time.LocalTime/now)
+       (.format (java.time.format.DateTimeFormatter/ofPattern "HH:mm:ss"))
+       (format "[%s]")))
 
 
 (defn fill-string
@@ -23,22 +27,18 @@
        (apply str)))
 
 
-(defn get-timestamp
-  "Get current local time.
-
-  Return a string formatted as \"[HH:mm:ss]\"."
-  []
-  (->> (java.time.LocalTime/now)
-       (.format (java.time.format.DateTimeFormatter/ofPattern "HH:mm:ss"))
-       (format "[%s]")))
-
-
 (defn add-borders
   "Create a string consisting of ch followed by s followed by ch."
   [s ch]
   (string/join [ch s ch]))
 
 
+(defn printfln
+  "Print formatted output, as per format, followed by (newline)."
+  [fmt & args]
+  (println (apply format fmt args)))
+
+
 (defn print-line
   "Print a simple line of length \"page-width\" by repeating ch,
   followed by (newline).  If border-ch is given, change the first and
@@ -87,6 +87,24 @@
           coll)))
 
 
+(defn print-settings
+  "Print settings using a nice layout."
+  [interval task-names watch-names]
+  (let [padding-tasks   (format "%s  Tasks:    " padding)
+        padding-watches (format "%s  Watches:  " padding)
+        padding-rest    (format "%s            " padding)]
+    (newline)
+    (printfln "%s  Probe:    every %s seconds"
+              (get-timestamp)
+              interval)
+    (newline)
+    (print-list padding-tasks padding-rest "-"
+                (map name task-names))
+    (newline)
+    (print-list padding-watches padding-rest "-"
+                (map name watch-names))))
+
+
 (defn exit-after-printing-help-and-errors
   "Print help, command line parsing errors (if any) and exit with
   given exit-code."
@@ -105,21 +123,3 @@
     (newline)
     (flush)
     (System/exit exit-code)))
-
-
-(defn print-settings
-  "Print settings using a nice layout."
-  [interval task-names watch-names]
-  (let [padding-tasks   (format "%s  Tasks:    " padding)
-        padding-watches (format "%s  Watches:  " padding)
-        padding-rest    (format "%s            " padding)]
-    (newline)
-    (printfln "%s  Probe:    every %s seconds"
-              (get-timestamp)
-              interval)
-    (newline)
-    (print-list padding-tasks padding-rest "-"
-                (map name task-names))
-    (newline)
-    (print-list padding-watches padding-rest "-"
-                (map name watch-names))))

From cfc53641792900c1ae46191606f8e1e75124f862 Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Sun, 12 Jul 2020 11:41:20 +0200
Subject: [PATCH 17/19] place guards around IO operations

---
 src/de/mzuther/moccafaux/core.clj    | 83 ++++++++++++++--------------
 src/de/mzuther/moccafaux/helpers.clj | 28 +++++-----
 2 files changed, 55 insertions(+), 56 deletions(-)

diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index 2df3a0f..b2f17fd 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -17,19 +17,19 @@
 
 (def preferences
   (try (let [;; "io/file" takes care of line separators
-             file-name  (io/file (System/getProperty "user.home")
-                                 ".config" "moccafaux" "config.json")
+             file-name  (io! (io/file (System/getProperty "user.home")
+                                      ".config" "moccafaux" "config.json"))
              user-prefs (json/read-str (slurp file-name)
                                        :key-fn keyword)]
          (if (map? user-prefs)
            user-prefs
            (throw (Exception. "JSON error (not handled by library)"))))
        (catch Throwable e
-         (helpers/print-header)
-         (newline)
-         (println (str e))
-         (newline)
-         (flush)
+         (io! (helpers/print-header)
+              (newline)
+              (println (str e))
+              (newline)
+              (flush))
          (System/exit 1))))
 
 
@@ -112,18 +112,18 @@
   keyword is :forked if command has forked, :success if command has
   exited with a zero exit code, and :failed in any other case."
   [command fork?]
-  (let [new-process (popen/popen ["sh" "-c" command])]
-    (if-not fork?
-      (if (zero? (popen/exit-code new-process))
-        (make-process-object new-process :success)
-        (make-process-object new-process :failed))
-      (do
-        ;; wait for 10 ms to check whether the process is actually
-        ;; created and running
-        (Thread/sleep 10)
-        (if (popen/running? new-process)
-          (make-process-object new-process :forked)
-          (make-process-object new-process :failed))))))
+  (io! (let [new-process (popen/popen ["sh" "-c" command])]
+         (if-not fork?
+           (if (zero? (popen/exit-code new-process))
+             (make-process-object new-process :success)
+             (make-process-object new-process :failed))
+           (do
+             ;; wait for 10 ms to check whether the process is actually
+             ;; created and running
+             (Thread/sleep 10)
+             (if (popen/running? new-process)
+               (make-process-object new-process :forked)
+               (make-process-object new-process :failed)))))))
 
 
 (defn- watch-exec
@@ -172,19 +172,19 @@
         command   (sp/select-one [:command] prefs)
         fork?     (sp/select-one [:fork] prefs)
         message   (sp/select-one [:message] prefs)]
-    (when command
-      (newline)
-      (helpers/printfln "%s  Task:     %s %s"
-                        (helpers/get-timestamp) (name new-state) (name task))
-      (helpers/printfln "%s  State:    %s"
-                        helpers/padding message)
-      (helpers/printfln "%s  Command:  %s"
-                        helpers/padding command)
-      ;; execute command (finally)
-      (let [{exit-state :state} (shell-exec command fork?)]
-        (helpers/printfln "%s  Result:   %s"
-                          helpers/padding (name exit-state))
-        exit-state))))
+    (io! (when command
+           (newline)
+           (helpers/printfln "%s  Task:     %s %s"
+                             (helpers/get-timestamp) (name new-state) (name task))
+           (helpers/printfln "%s  State:    %s"
+                             helpers/padding message)
+           (helpers/printfln "%s  Command:  %s"
+                             helpers/padding command)
+           ;; execute command (finally)
+           (let [{exit-state :state} (shell-exec command fork?)]
+             (helpers/printfln "%s  Result:   %s"
+                               helpers/padding (name exit-state))
+             exit-state)))))
 
 
 (defn enable-disable-or-nil?
@@ -230,8 +230,8 @@
     (doseq [task task-names]
       (update-task task))
     (when update-needed?
-      (newline)
-      (helpers/print-line \-))
+      (io! (newline)
+           (helpers/print-line \-)))
     (dosync (ref-set task-states
                      new-task-states))))
 
@@ -253,29 +253,28 @@
                       (when-not (>= seconds-late interval)
                         (f timestamp))))
                   ;; display exception and kill scheduler
-                  {:error-handler (fn [e] (println (str e)))}))
+                  {:error-handler (fn [e] (io! (println (str e))))}))
 
 
 (defn -main
   "Print information on application and schedule watchers."
   [& unparsed-args]
-  (helpers/print-header)
+  (io! (helpers/print-header))
 
   (let [args (cli/parse-opts unparsed-args cli-options)]
     (cond
       ;; display errors and exit
       (sp/select-one [:errors] args)
-        (helpers/exit-after-printing-help-and-errors args 2)
+        (io! (helpers/exit-after-printing-help-and-errors args 2))
 
       ;; display help and exit
       (sp/select-one [:options :help] args)
-        (helpers/exit-after-printing-help-and-errors args 0))
+        (io! (helpers/exit-after-printing-help-and-errors args 0)))
 
     ;; display settings and enter main loop
     (let [interval (sp/select-one [:scheduler :probing-interval] preferences)]
-      (helpers/print-settings interval task-names watch-names)
-
-      (newline)
-      (helpers/print-line \-)
+      (io! (helpers/print-settings interval task-names watch-names)
+           (newline)
+           (helpers/print-line \-))
 
       (start-scheduler update-status interval))))
diff --git a/src/de/mzuther/moccafaux/helpers.clj b/src/de/mzuther/moccafaux/helpers.clj
index 9d4bf3e..f31de01 100644
--- a/src/de/mzuther/moccafaux/helpers.clj
+++ b/src/de/mzuther/moccafaux/helpers.clj
@@ -109,17 +109,17 @@
   "Print help, command line parsing errors (if any) and exit with
   given exit-code."
   [args exit-code]
-  (let [{:keys [summary errors]} args]
-    (when errors
-      (newline)
-      (doseq [error errors]
-        (println "ERROR:" error)))
-
-    (newline)
-    (println "Usage: java -jar moccafaux.jar [OPTION...]")
-    (newline)
-    ;; display command line help
-    (println summary)
-    (newline)
-    (flush)
-    (System/exit exit-code)))
+  (io! (let [{:keys [summary errors]} args]
+         (when errors
+           (newline)
+           (doseq [error errors]
+             (println "ERROR:" error)))
+
+         (newline)
+         (println "Usage: java -jar moccafaux.jar [OPTION...]")
+         (newline)
+         ;; display command line help
+         (println summary)
+         (newline)
+         (flush)))
+  (System/exit exit-code))

From 83ad0c955370ab1b19b24da16f9c90cf83652dab Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Sun, 12 Jul 2020 12:43:57 +0200
Subject: [PATCH 18/19] fix reflection warning

---
 project.clj                       | 10 +++++-----
 src/de/mzuther/moccafaux/core.clj |  2 +-
 2 files changed, 6 insertions(+), 6 deletions(-)

diff --git a/project.clj b/project.clj
index c8a99ef..7713a89 100644
--- a/project.clj
+++ b/project.clj
@@ -17,11 +17,11 @@
   :uberjar-name "moccafaux.jar"
 
   :profiles {:debug   {:debug       true
-                       :injections  [(newline)
-                                     (doseq [s (into {} (System/getProperties))]
-                                       (prn s))
-                                     (newline)
-                                     (flush)]
+                       ;; :injections  [(newline)
+                       ;;               (doseq [s (into {} (System/getProperties))]
+                       ;;                 (prn s))
+                       ;;               (newline)
+                       ;;               (flush)]
                        :global-vars {*warn-on-reflection* true
                                      *assert*             true}}
              :uberjar {:aot         :all
diff --git a/src/de/mzuther/moccafaux/core.clj b/src/de/mzuther/moccafaux/core.clj
index b2f17fd..b6fde87 100644
--- a/src/de/mzuther/moccafaux/core.clj
+++ b/src/de/mzuther/moccafaux/core.clj
@@ -245,7 +245,7 @@
                                       (java.time.Duration/ofSeconds interval))
                   (fn [timestamp]
                     (let [actual-millis (.toEpochMilli (java.time.Instant/now))
-                          target-millis (.toEpochMilli timestamp)
+                          target-millis (.toEpochMilli ^java.time.Instant timestamp)
                           seconds-late  (/ (- actual-millis target-millis)
                                            1000.0)]
                       ;; skip scheduled instants that were actually

From 7086ef1c79465709f0861c6c524f520cdeb419a2 Mon Sep 17 00:00:00 2001
From: Martin Zuther <code@mzuther.de>
Date: Mon, 13 Jul 2020 13:17:02 +0200
Subject: [PATCH 19/19] v1.2.0: add command line help and version display

- add Leiningen debug profile

- add a first unit test

- improve console logging

- return process object from "shell-exec"

- place guards around IO operations

- re-factor code

- fix reflection warning
---
 CHANGELOG.md | 44 +++++++++++++++++++++++++++++++++++---------
 project.clj  |  2 +-
 2 files changed, 36 insertions(+), 10 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 504fb51..006e547 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -10,36 +10,61 @@ file. This change log follows the conventions of
 
 
 
+## [1.2.0] - 2020-07-13
+### Added
+
+- add command line help and version display
+
+- add Leiningen debug profile
+
+- add a first unit test
+
+### Changed
+
+- improve console logging
+
+- return process object from "shell-exec"
+
+- place guards around IO operations
+
+- re-factor code
+
+## Fixed
+
+- fix reflection warning
+
+
+
 ## [1.1.0] - 2020-06-23
 ### Added
 
-* let users define tasks and do not limit the number of tasks
+- let users define tasks and do not limit the number of tasks
 
-* add complete documentation
+- add complete documentation
 
-* display an error message if the settings file cannot be opened or is
+- display an error message if the settings file cannot be opened or is
   broken
 
 ### Changed
 
-* completely change the structure of the settings file
+- completely change the structure of the settings file
 
-* do not skip the first state update when MoccaFaux is started
+- do not skip the first state update when MoccaFaux is started
 
-* drop the default settings
+- drop the default settings
 
-* rename the sample settings file
+- rename the sample settings file
 
 ## Fixed
 
-* kill the scheduler and end MoccaFaux if an exception is thrown
+- kill the scheduler and end MoccaFaux if an exception is thrown
 
 
 
 ## [1.0.0] - 2020-06-20
 ### Changed
 
-* This is the first release.
+- This is the first release.
 
 
 [keepachangelog.com]:  http://keepachangelog.com/
@@ -47,3 +72,4 @@ file. This change log follows the conventions of
 
 [1.0.0]:  https://github.com/mzuther/moccafaux/commits/v1.0.0
 [1.1.0]:  https://github.com/mzuther/moccafaux/commits/v1.1.0
+[1.2.0]:  https://github.com/mzuther/moccafaux/commits/v1.2.0
diff --git a/project.clj b/project.clj
index 7713a89..b3ab042 100644
--- a/project.clj
+++ b/project.clj
@@ -1,4 +1,4 @@
-(defproject de.mzuther/moccafaux.core "1.1.4-SNAPSHOT"
+(defproject de.mzuther/moccafaux.core "1.2.0"
   :description "Adapt power management to changes in the environment."
   :url "https://github.com/mzuther/moccafaux"
   :license {:name "EPL-2.0 OR GPL-2.0-or-later WITH Classpath-exception-2.0"