spit

user=> (spit "flubber.txt" "test")
nil
user=> (slurp "flubber.txt")
"test"

user=> (spit "event.log" "test 1\n" :append true)
nil

user=> (spit "event.log" "test 2\n" :append true)
nil

user=> (println (slurp "event.log"))
test 1
test 2

nil

(defn append-to-file
  "Uses spit to append to a file specified with its name as a string, or
   anything else that writer can take as an argument.  s is the string to
   append."     
  [file-name s]
  (spit file-name s :append true))

;;Create a record and save a log message to a log file
;;Constructor with side effects

;;define a Person record
(defrecord Person [fname lname])

;;define a function to save a log message into the log.txt using spit and :append
(defn log-entry [msg] (spit "log.txt" (apply str msg "\n") :append true))

;;build the constructor which: 1) log the message; 2)create a Person
(defn make-person [fname lname]
  (log-entry (apply str "[log] New Person created : " lname "," fname))
    (->Person fname lname))

;;create a person
(def person (make-person "John" "Smith"))

;;print the content of the log.txt to the console
(println  (slurp "log.txt"))

; ClojureCLR doesn't use :append, use this instead
(spit "hi.txt" "Test 1\n" :file-mode System.IO.FileMode/Append)

;; Spitting map, adds "," between key-value pairs
(spit "hi.txt" {:a 1 :b 2})

;; Now let's read it
(slurp "hello.txt")
;; => "{:a 1, :b 2}"