diff --git a/main.py b/main.py
old mode 100644
new mode 100755
diff --git a/squinnondation/squinnondation.py b/squinnondation/squinnondation.py
index 7808aaa..a2e74b0 100644
--- a/squinnondation/squinnondation.py
+++ b/squinnondation/squinnondation.py
@@ -1,4 +1,27 @@
+# Copyright (C) 2020 by eichhornchen, ÿnérant
+# SPDX-License-Identifier: GPL-3.0-or-later
+
+from argparse import ArgumentParser, Namespace
+
+
 class Squinnondation:
+    args: Namespace
+    client_address: str
+    client_port: int
+
+    def parse_arguments(self) -> None:
+        parser = ArgumentParser(description="MIRC client.")
+        parser.add_argument('address', type=str, default="localhost", help="Address of the client.")
+        parser.add_argument('port', type=int, default=2500, help="Port of the client. Must be between 1024 and 65535.")
+        self.args = parser.parse_args()
+
+        if not (1024 <= self.args.port <= 65535):
+            raise ValueError("The port must be between 1024 and 65535.")
+
+        self.client_address = self.args.address
+        self.client_port = self.args.port
+
     @staticmethod
-    def main() -> None:
-        print("Hello world!")
+    def main() -> None:  # pragma: no cover
+        instance = Squinnondation()
+        instance.parse_arguments()
diff --git a/squinnondation/test/squinnondation_test.py b/squinnondation/test/squinnondation_test.py
new file mode 100644
index 0000000..1364565
--- /dev/null
+++ b/squinnondation/test/squinnondation_test.py
@@ -0,0 +1,25 @@
+import sys
+import unittest
+
+from squinnondation.squinnondation import Squinnondation
+
+
+class TestSquinnondation(unittest.TestCase):
+    def test_arguments(self):
+        """
+        Parse arguments and check errors.
+        """
+        squinnondation = Squinnondation()
+
+        # No parameter was given
+        self.assertRaises(SystemExit, squinnondation.parse_arguments)
+
+        # Wrong port
+        sys.argv = ["squinnondation", "localhost", "42"]
+        self.assertRaises(ValueError, squinnondation.parse_arguments)
+
+        # Esnure that the parsing is correct
+        sys.argv = ["squinnondation", "localhost", "4242"]
+        squinnondation.parse_arguments()
+        self.assertEqual(squinnondation.client_address, "localhost")
+        self.assertEqual(squinnondation.client_port, 4242)
diff --git a/tox.ini b/tox.ini
index fd45328..a0ac22e 100644
--- a/tox.ini
+++ b/tox.ini
@@ -39,7 +39,7 @@ exclude =
     .cache,
     .eggs
 max-complexity = 15
-max-line-length = 80
+max-line-length = 120
 import-order-style = google
 application-import-names = flake8
 format = ${cyan}%(path)s${reset}:${yellow_bold}%(row)d${reset}:${green_bold}%(col)d${reset}: ${red_bold}%(code)s${reset} %(text)s