First commit

common/Practical.c

@@ -0,0 +1,12 @@
+#include <netdb.h>
+#include <stddef.h>
+
+#include "Practical.h"
+
+int proto_get_num(const char *name) {
+    struct protoent *protoent = getprotobyname(name);
+    if (protoent == NULL) {
+        DieWithSystemMessage("getprotobyname");
+    }
+    return protoent->p_proto;
+}