close #30 added overwritable help command parameter and fixed some compiler issues (some of them only appeared when compiling with optimization)

example/main.c

@@ -52,6 +52,9 @@ static shellmatta_retCode_t doSome(shellmatta_handle_t handle, const char *argum
 
     shellmatta_write(handle, "blubb\r\n", 7u);
 
+    (void)arguments;
+    (void)length;
+
     return SHELLMATTA_OK;
 }
 shellmatta_cmd_t doSomeCmd = {"adoSome2", "adof2", "Function does something", "use me, please", doSome, NULL};
@@ -62,6 +65,9 @@ static shellmatta_retCode_t removeCmdFct(shellmatta_handle_t handle, const char
 
     shellmatta_removeCmd(handle, &doSomeCmd);
 
+    (void)arguments;
+    (void)length;
+
     return SHELLMATTA_OK;
 }
 shellmatta_cmd_t removeCommand = {"remove", "r", "Function removes a command", "", removeCmdFct, NULL};
@@ -71,6 +77,10 @@ static shellmatta_retCode_t quit(shellmatta_handle_t handle, const char *argumen
 {
     exitRequest = true;
 
+    (void)handle;
+    (void)arguments;
+    (void)length;
+
     return SHELLMATTA_OK;
 }
 shellmatta_cmd_t quitCommand = {"quit", "q", "Function quits the shell", "", quit, NULL};
@@ -83,17 +93,23 @@ shellmatta_retCode_t writeFct(const char* data, uint32_t length)
     return SHELLMATTA_OK;
 }
 
-int main(void)
+int main(int argc, char **argv)
 {
     static char buffer[1024];
     static char historyBuffer[4096];
     static shellmatta_instance_t instance;
 
-    f = open("/dev/pts/3", O_RDWR | O_SYNC);
+    if(2 != argc)
+    {
+        printf("%s <serial device>\n", argv[0u]);
+        return -1;
+    }
+
+    f = open(argv[1u], O_RDWR | O_SYNC);
 
     if (f < 0)
     {
-        printf("failure %d\n", errno);
+        printf("failure opening device %s %d\n", argv[1u], errno);
         return f;
     }