diff --git a/.vscode/settings.json b/.vscode/settings.json
index cbe4c24..40c4294 100644
--- a/.vscode/settings.json
+++ b/.vscode/settings.json
@@ -34,7 +34,10 @@
         "mpl-args.h": "c",
         "*.in": "cpp",
         "signal.h": "c",
-        "stdio.h": "c"
+        "stdio.h": "c",
+        "getopt.h": "c",
+        "mpl-common.h": "c",
+        "cerrno": "c"
     },
     "cmake.configureOnOpen": false
 }
\ No newline at end of file
diff --git a/CMakeLists.txt b/CMakeLists.txt
index 8b5b116..ac66859 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,7 +1,7 @@
 cmake_minimum_required(VERSION 3.18.4)
 project(mportlink)
 
-# set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Werror -Os")
+set(CMAKE_C_FLAGS "${CMAKE_C_FLAGS} -Wall -Werror -Os")
 
 set(VERSION_MAJOR 0)
 set(VERSION_MINOR 1)
diff --git a/src/mpl-common.c b/src/mpl-common.c
new file mode 100644
index 0000000..355c8a3
--- /dev/null
+++ b/src/mpl-common.c
@@ -0,0 +1,111 @@
+/*
+ * mpl-common.c
+ *
+ * by Alexander Zhirov (alexander@zhirov.kz)
+ * Telegram @alexanderzhirov
+ */
+
+#include "mpl-common.h"
+
+#include <sys/stat.h>
+#include <sys/file.h>
+
+#define LOCKFILE "/run/lock/mportlink.lock"
+
+static int mpl_create_dongle_dir()
+{
+    struct stat st;
+
+    if (stat(MPL_DONGLE_PATH, &st) == 0)
+    {
+        if (!S_ISDIR(st.st_mode))
+        {
+            MPLOG(LOG_WARNING, "%s exists and is not a directory", MPL_DONGLE_PATH);
+            return 1;
+        }
+    }
+    else if (mkdir(MPL_DONGLE_PATH, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH) == -1)
+    {
+        MPLOG(LOG_ERR, "unable to create a directory %s", MPL_DONGLE_PATH);
+        return 1;
+    }
+
+    return 0;
+}
+
+void static mpl_free(MPL *mpl)
+{
+    if (mpl)
+        free(mpl);
+}
+
+MPL *mpl_init(MPL_PARAMETERS *parameters)
+{
+    MPL *mpl = (MPL *)calloc(1, sizeof(MPL));
+
+    if (!mpl)
+    {
+        MPLOG(LOG_ERR, "error getting the MPL structure");
+        exit(1);
+    }
+
+    mpl->parameters.check_device = parameters->check_device;
+    mpl->cancellable.signal = 0;
+    mpl->cancellable.exit = 0;
+
+    mpl->fd = open(LOCKFILE, O_CREAT | O_RDWR, 0644);
+    if (mpl->fd < 0)
+    {
+        MPLOG(LOG_ERR, "unable to create a lockfile");
+        exit(1);
+    }
+
+    int rc = flock(mpl->fd, LOCK_EX | LOCK_NB);
+    if (rc || errno == EWOULDBLOCK)
+    {
+        MPLOG(LOG_ERR, "only one instance of %s is allowed", MPL_NAME);
+        exit(1);
+    }
+
+    if (mpl_create_dongle_dir())
+    {
+        MPLOG(LOG_ERR, "%s will be stopped", MPL_NAME);
+        exit(1);
+    }
+
+    if (mpl_udev_init(&mpl->udev))
+    {
+        MPLOG(LOG_ERR, "%s will be stopped", MPL_NAME);
+        mpl_free(mpl);
+        exit(1);
+    }
+
+    MPLOG(LOG_NOTICE, "starting the %s daemon", MPL_NAME);
+
+    return mpl;
+}
+
+void mpl_stop(MPL *mpl)
+{
+    mpl_udev_free(&mpl->udev);
+
+    if (mpl->cancellable.exit)
+    {
+        flock(mpl->fd, LOCK_UN);
+        MPLOG(LOG_NOTICE, "stopping the %s daemon", MPL_NAME);
+    }
+    else
+        MPLOG(LOG_NOTICE, "successful completion of the process %d", getpid());
+
+    mpl_free(mpl);
+
+    closelog();
+}
+
+void mpl_loop(MPL *mpl)
+{
+    if (mpl->parameters.check_device)
+        mpl_udev_check_devices(&mpl->udev);
+    
+    mpl_udev_loop(&mpl->udev, &mpl->cancellable);
+}
diff --git a/src/mpl-common.h b/src/mpl-common.h
new file mode 100644
index 0000000..fd85c45
--- /dev/null
+++ b/src/mpl-common.h
@@ -0,0 +1,31 @@
+/*
+ * mpl-common.h
+ *
+ * by Alexander Zhirov (alexander@zhirov.kz)
+ * Telegram @alexanderzhirov
+ */
+
+#ifndef MPL_COMMON_H_
+#define MPL_COMMON_H_
+
+#include "mpl-lib.h"
+#include "mpl-udev.h"
+
+typedef struct
+{
+    int check_device;
+} MPL_PARAMETERS;
+
+typedef struct
+{
+    int fd;
+    MPL_PARAMETERS parameters;
+    MPL_CANCELLABLE cancellable;
+    MPL_UDEV udev;
+} MPL;
+
+MPL *mpl_init(MPL_PARAMETERS *parameters);
+void mpl_stop(MPL *mpl);
+void mpl_loop(MPL *mpl);
+
+#endif
diff --git a/src/mpl-core.c b/src/mpl-core.c
index d60fc6a..8f93523 100644
--- a/src/mpl-core.c
+++ b/src/mpl-core.c
@@ -5,108 +5,83 @@
  * Telegram @alexanderzhirov
  */
 
+#include "mpl-lib.h"
 #include "mpl-core.h"
 
-#include <sys/stat.h>
-#include <sys/file.h>
-#include <unistd.h>
+#include <regex.h>
+#include <dirent.h>
+#include <fcntl.h>
 
-#define LOCKFILE "/run/lock/mportlink.lock"
-#define DEV_PATH "/dev/"
-#define DONGLE_PATH (DEV_PATH "dongle/")
-
-static int mpl_create_dongle_dir()
+int device_path(const char *dirname, int num)
 {
-    struct stat st;
+    DIR *dir;
+    struct dirent *ent;
+    regex_t regex;
+    const char *pattern = "^ttyUSB[0-9]*$";
 
-    if (stat(DONGLE_PATH, &st) == 0)
+    int ret = regcomp(&regex, pattern, REG_EXTENDED);
+    if (ret != 0)
     {
-        if (!S_ISDIR(st.st_mode))
-        {
-            MPLOG(LOG_WARNING, "%s exists and is not a directory", DONGLE_PATH);
-            return 1;
-        }
-    }
-    else if (mkdir(DONGLE_PATH, S_IRWXU | S_IRGRP | S_IXGRP | S_IROTH | S_IXOTH) == -1)
-    {
-        MPLOG(LOG_ERR, "unable to create a directory %s", DONGLE_PATH);
+        printf("Failed to compile regular expression\n");
         return 1;
     }
 
+    dir = opendir(dirname);
+    if (dir == NULL)
+    {
+        printf("Failed to open directory\n");
+        regfree(&regex);
+        return 1;
+    }
+
+    while ((ent = readdir(dir)) != NULL)
+    {
+        if (strcmp(ent->d_name, ".") == 0 || strcmp(ent->d_name, "..") == 0)
+        {
+            continue;
+        }
+
+        ret = regexec(&regex, ent->d_name, 0, NULL, 0);
+
+        if (ret == 0)
+        {
+            printf("Found a file matching the pattern: %s\n", ent->d_name);
+
+            char *path = (char *)calloc(strlen(MPL_DEV_PATH) + strlen(ent->d_name) + 1, sizeof(char));
+            strcpy(path, MPL_DEV_PATH);
+            strcat(path, ent->d_name);
+
+            int fd = open(path, O_RDWR);
+            if (fd < 0)
+            {
+                printf("Не удалось открыть USB устройство.\n");
+                free(path);
+                continue;
+            }
+
+            char *tty = ttyname(fd);
+            close(fd);
+
+            if (tty != NULL)
+            {
+                printf("Найдено устройство tty: %s\n", tty);
+
+                // if (!num)
+                //     print_imei(tty);
+            }
+            else
+            {
+                printf("Устройство tty не найдено\n");
+            }
+        }
+        else if (ret != REG_NOMATCH)
+        {
+            printf("Failed to apply regular expression\n");
+        }
+    }
+
+    regfree(&regex);
+    closedir(dir);
+
     return 0;
 }
-
-void static mpl_free(MPL *mpl)
-{
-    if (mpl)
-        free(mpl);
-}
-
-MPL *mpl_init(MPL_PARAMETERS *parameters)
-{
-    MPL *mpl = (MPL *)calloc(1, sizeof(MPL));
-
-    if (!mpl)
-    {
-        MPLOG(LOG_ERR, "error getting the MPL structure");
-        exit(1);
-    }
-
-    mpl->parameters.check_device = parameters->check_device;
-    mpl->cancellable.signal = 0;
-    mpl->cancellable.exit = 0;
-
-    mpl->fd = open(LOCKFILE, O_CREAT | O_RDWR, 0644);
-    if (mpl->fd < 0)
-    {
-        MPLOG(LOG_ERR, "unable to create a lockfile");
-        exit(1);
-    }
-
-    int rc = flock(mpl->fd, LOCK_EX | LOCK_NB);
-    if (rc || errno == EWOULDBLOCK)
-    {
-        MPLOG(LOG_ERR, "only one instance of %s is allowed", MPL_NAME);
-        exit(1);
-    }
-
-    if (mpl_create_dongle_dir())
-    {
-        MPLOG(LOG_ERR, "%s will be stopped", MPL_NAME);
-        exit(1);
-    }
-
-    if (mpl_udev_init(&mpl->udev))
-    {
-        MPLOG(LOG_ERR, "%s will be stopped", MPL_NAME);
-        mpl_free(mpl);
-        exit(1);
-    }
-
-    MPLOG(LOG_NOTICE, "starting the %s daemon", MPL_NAME);
-
-    return mpl;
-}
-
-void mpl_stop(MPL *mpl)
-{
-    mpl_udev_free(&mpl->udev);
-
-    flock(mpl->fd, LOCK_UN);
-
-    mpl_free(mpl);
-
-    if (mpl->cancellable.exit)
-        MPLOG(LOG_NOTICE, "stopping the %s daemon", MPL_NAME);
-    else
-        MPLOG(LOG_NOTICE, "successful completion of the process %d", getpid());
-    closelog();
-}
-
-void mpl_loop(MPL *mpl)
-{
-    if (mpl->parameters.check_device)
-        mpl_udev_check_devices(&mpl->udev);
-    
-    mpl_udev_loop(&mpl->udev, &mpl->cancellable);
-}
diff --git a/src/mpl-core.h b/src/mpl-core.h
index 2047178..76bc1b1 100644
--- a/src/mpl-core.h
+++ b/src/mpl-core.h
@@ -8,24 +8,6 @@
 #ifndef MPL_CORE_H_
 #define MPL_CORE_H_
 
-#include "mpl-lib.h"
-#include "mpl-udev.h"
-
-typedef struct
-{
-    int check_device;
-} MPL_PARAMETERS;
-
-typedef struct
-{
-    int fd;
-    MPL_PARAMETERS parameters;
-    MPL_CANCELLABLE cancellable;
-    MPL_UDEV udev;
-} MPL;
-
-MPL *mpl_init(MPL_PARAMETERS *parameters);
-void mpl_stop(MPL *mpl);
-void mpl_loop(MPL *mpl);
+int device_path(const char *dirname, int num);
 
 #endif
diff --git a/src/mpl-lib.h b/src/mpl-lib.h
index 4facc06..ca818f0 100644
--- a/src/mpl-lib.h
+++ b/src/mpl-lib.h
@@ -14,8 +14,11 @@
 #include <stdio.h>
 #include <string.h>
 #include <syslog.h>
+#include <unistd.h>
 
 #define MPL_NAME "mportlink"
+#define MPL_DEV_PATH "/dev/"
+#define MPL_DONGLE_PATH (MPL_DEV_PATH "dongle/")
 
 #define MPLOG(PRIORITY, fmt, ...) do { \
         char buf[256]; \
diff --git a/src/mpl-udev.c b/src/mpl-udev.c
index 27ccaf2..acfee46 100644
--- a/src/mpl-udev.c
+++ b/src/mpl-udev.c
@@ -6,6 +6,7 @@
  */
 
 #include "mpl-udev.h"
+#include "mpl-core.h"
 
 #include <unistd.h>
 #include <sys/wait.h>
@@ -80,12 +81,13 @@ int mpl_udev_check_devices(MPL_UDEV *udev)
             continue;
 
         const char *sysattr_value = udev_device_get_sysattr_value(dev, "bInterfaceNumber");
-        printf("Номер порта: %s\n", sysattr_value);
+        printf("Number of port: %s\n", sysattr_value);
 
         // int num = atoi(sysattr_value);
 
         const char *devsyspath = udev_device_get_syspath(dev);
         printf("syspath: %s\n", devsyspath);
+
         // device_path(syspaths, num);
 
         udev_device_unref(dev);
@@ -184,6 +186,5 @@ void mpl_udev_loop(MPL_UDEV *udev, MPL_CANCELLABLE *cancellable)
     if (cancellable->exit)
         return;
 
-    sleep(5);
-    printf("exit");
+    device_path(path_to_device, port_number);
 }
diff --git a/src/mpl.c b/src/mpl.c
index 74e3a36..11c66b7 100644
--- a/src/mpl.c
+++ b/src/mpl.c
@@ -5,9 +5,8 @@
  * Telegram @alexanderzhirov
  */
 
-#include <getopt.h>
-
 #include "mpl.h"
+#include <getopt.h>
 
 static MPL *mpl;
 
diff --git a/src/mpl.h b/src/mpl.h
index e5975dc..ab0284e 100644
--- a/src/mpl.h
+++ b/src/mpl.h
@@ -12,7 +12,6 @@
 #define VERSION "unrelease"
 #endif
 
-#include "mpl-lib.h"
-#include "mpl-core.h"
+#include "mpl-common.h"
 
 #endif