diff --git a/README.md b/README.md
index e2c027e..911fd3f 100644
--- a/README.md
+++ b/README.md
@@ -7,19 +7,29 @@ _Tommaso Rodolfo Masera_.
 
 Run the file `gui.rkt` using *DrRacket* or the `racket` CLI tool.
 
+A CLI version of the interpreter is avaliable. In order to run it, execute:
+
+`./cli.rkt <name-of-file.bf>`
+
+More documentation of this command is avaliable using the `-h` flag.
+
 ## Current features
 
 - Brainf\*ck interpreter works for the instructions `[`, `]` `+`, `-`, `<`, `>`
-  , `.`;
+  , `.`, ',';
 - Done simple editor GUI with *Run* button and output window.
 - Editor supports basic syntax highlighting.
 
 ## Bugs
 
-- `,` function not implemented (will crash the program if encountered);
 - No validation or user-friendly error handling.
 
 ## Feedback
 
-Add documentation about the language for someone that doesn't know it. How does it work? What are the instructions? What do they do? Example programs?
-In your "running" section explain how to run the interpreter without the GUI.
+### Add documentation about the language for someone that doesn't know it. How does it work? What are the instructions? What do they do? Example programs?
+
+WIP
+
+### In your "running" section explain how to run the interpreter without the GUI.
+
+Done with `cli.rkt`.
diff --git a/cli.rkt b/cli.rkt
new file mode 100755
index 0000000..dbfcf39
--- /dev/null
+++ b/cli.rkt
@@ -0,0 +1,66 @@
+#! /usr/bin/env racket
+#lang racket
+
+(require "interpreter.rkt"
+         racket/block)
+
+(define is-program (make-parameter #f))
+(define show-tape (make-parameter #f))
+
+; Init flags and argument from cli
+(define file-or-program
+  (command-line
+   #:program
+   "bfrkt"
+   #:once-each
+   [("-p" "--program") "Interpret the argument as a program,"
+                       "not as a filename"
+                       (is-program #t)]
+   [("-t" "--tape") "Display trace of program state at the end of execution"
+                    (show-tape #t)]
+   #:args (arg)
+   arg))
+
+; The program to execute
+(define program
+  (string->program
+   (if (is-program)
+       ; Set program to file-or-program if `-p` is set
+       file-or-program 
+       ; Otherwise parse the contents of the file whose name is file-or-program
+       (file->string file-or-program #:mode 'text))))
+
+; end-print: ProgState -> ()
+; Given the fineal prog-state, prints the results according to the flags.
+(define (end-print p)
+  (display (prog-state-output p))
+  (if (show-tape) (display-status p) (void)))
+
+; display-trace: ProgState -> _
+; Given a prog-state, prints a trace of it to stdout.
+(define (display-status p)
+  (define t (prog-state-tape p))
+  (define dp (prog-state-dp p))
+  (display "######")
+  (display "\nTape: ")
+  (display (foldr (lambda (x y) (string-append x " " y)) 
+                  ""
+                  (map (lambda (x) (number->string x)) t)))
+  (display "\nData pointer: ")
+  (display dp)
+  (display "\n######"))
+
+; execute-cli: Program -> ()
+; Executers the program in `program` reading and writing respectively from 
+; stdin and stdout.
+(define (execute-cli program)
+  (execute (program->prog-state program)
+           end-print
+           (lambda (call)
+             (display "Input a character: ")
+             (define data-read (read-line (current-input-port) 'any))
+             (if (eof-object? data-read)
+                 (call 0)
+                 (call (char->integer (string-ref data-read 0)))))))
+
+(execute-cli program)