# File I/O

{{tag>clojure file i/o}}

### Reading the Contents of a File as an Entire String

<code>
(ns clojure.examples.hello
   (:gen-class))

;; This program displays Hello World
(defn Example []
   (def string1 (slurp "Example.txt"))
   (println string1))
   
(Example)
</code>

### Reading the Contents of a File One Line at a Time

<code>
(ns clojure.examples.hello
   (:gen-class))

;; This program displays Hello World
(defn Example []
   (with-open [rdr (clojure.java.io/reader "Example.txt")]
   (reduce conj [] (line-seq rdr))))
   
(Example)
</code>

### Writing ‘to’ Files

<code>
(ns clojure.examples.hello
   (:gen-class))

;; This program displays Hello World
(defn Example []
   (spit "Example.txt"
      "This is a string"))
</code>

### Writing ‘to’ Files One Line at a Time

<code>
(ns clojure.examples.hello
   (:gen-class))

;; This program displays Hello World
(defn Example []
   (with-open [w (clojure.java.io/writer "Example.txt" :append true)]
      (.write w (str "hello" "world"))))
      
(Example)
</code>

### Checking to See If a File Exists

<code>
(ns clojure.examples.hello
   (:gen-class))

;; This program displays Hello World
(defn Example []
   (println (.exists (clojure.java.io/file "Example.txt"))))
   
(Example)
</code>

### Reading from the Console

<code>
user->(read-line)
Hello World
</code>

## Refs

- https://www.tutorialspoint.com/clojure/clojure_file_io.htm