How to access rt pins in user space

Hi,
    I create some pins in the RT module, now I want to read and write pins' value in user space.I use the following code,but it failed.Is there any way to access RT module pins in the user space? The environment is Ubuntu20.04+xenomai3.1+linuxcnc2.9.Thanks!

---

    int compId;
    int ret;
    hal_float_t *pin_value;
    // init HAL
    compId = hal_init("user_program");
    if (compId < 0) {
        rtapi_print("HAL init failed\n");
        return -1;
    }
    pin_value = (hal_float_t*)hal_malloc(sizeof(hal_float_t));
    ret = hal_pin_float_new("kernel_pin", HAL_IN, &pin_value, compId);
    if (ret < 0) {
        rtapi_print("getting or creating pin failed!\n");
        hal_exit(compId);
        return -1;
    }

    ret = hal_link("user_program.kernel_pin", "ALT.I2600");
    if (ret < 0) {
        fprintf(stderr, "cann't bind signal!\n");
        hal_exit(compId);
        return -1;
    }
    hal_ready(compId);
    
    //*pin_value = 123.45;
    //rtapi_print("value is: %f\n", *pin_value);
    hal_exit(compId);

---

It prints some messages:
HAL: initializing hal_lib
HAL: initializing component 'user_program'
HAL: component 'user_program' initialized, ID = 28
smalloc_up: shmem available 1386552
HAL: ERROR: pin_new(kernel_pin) called with already-initialized memory
HAL: creating pin 'kernel_pin'
HAL: ERROR: data_ptr_addr not in shared memory

hi，thank you for your reply!
I have two modules running in realtime space. One is ethercat module, the other is shared memory module. The ethercat module tranfers data to shared memory module through pins, and I want to get these data from shared memory module in user space.

Can you give me some examples? Code or something.

That's great, thank you!

The HAL python module allows reading or arbitrary pins and signals without connecting to them.
It's written in C++ but shows the process and borrows C code from HAL cmd.

hi，here's another question. I want to read from and write to the module (for example the shared memory module in realtime space) through pins in user space.How can I solve the problem? Is there any code about this?

hi, thanks!
Is there any code or links to refer to?