Refactor UART handling and enhance user data structures

src/rfid_handler.c

@@ -0,0 +1,25 @@
+#include "rfid_handler.h"
+#include "users.h"
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <pthread.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <errno.h>
+#include <termios.h>
+#include <string.h>
+
+void *uartListener(void *arg)
+{
+    char *uart_address = (char *)arg;
+    int uart = open(uart_address, O_RDWR | O_NOCTTY | O_NDELAY);
+    if (uart == -1)
+    {
+        perror("Failed to open UART");
+        return NULL;
+    }
+
+    close(uart);
+    return NULL;
+}