feature: parsing with getopt pretty much done (some checks tbd)

include/parsing.h

@@ -0,0 +1,20 @@
+#pragma once
+
+#define NB_OPTIONS 5
+
+typedef enum {
+	FL_HELP,
+	FL_PORTS,
+	FL_IP,
+	FL_SPEEDUP,
+	FL_SCAN,
+} e_flag;
+
+struct option_lst {
+	e_flag flag;
+	char *arg;
+	struct option_lst *next;
+};
+
+struct option_lst *parse_options(int ac, char *const *av);
+char *get_option_arg(struct option_lst *options, e_flag flag);