Should be able to open a device

Makefile

@@ -1,5 +1,5 @@
 CFLAGS=-g -O0 -std=c11 -fPIE -pedantic -Wall # -Werror
-LDFLAGS=-lpthread
+LDFLAGS=-lpthread -levdev
 CC=gcc
 OBJECTS=main.o input_dev.o output_dev.o queue.o
 TARGET=rogue_enemy
@@ -7,7 +7,7 @@ TARGET=rogue_enemy
 all: $(TARGET)
 
 $(TARGET): $(OBJECTS)
-	$(CC) $(OBJECTS) -o $@
+	$(CC) $(LDFLAGS) $(OBJECTS) -o $@
 
 include depends
 

input_dev.c

@@ -12,25 +12,62 @@
 #include <dirent.h> 
 #include <stdio.h> 
 
-pthread_mutex_t input_acquire_mutex = PTHREAD_MUTEX_INITIALIZER;
+static const char *input_path = "/dev/input/";
+
+static struct libevdev* ev_matches(const char* sysfs_entry, const uinput_filters_t* const filters) {
+    struct libevdev *dev = NULL;
+
+    int fd = open(sysfs_entry, O_RDONLY);
+    if (fd < 0) {
+        fprintf(stderr, "Cannot open %s, device skipped.\n", sysfs_entry);
+        return NULL;
+    }
+
+    if (libevdev_new_from_fd(fd, &dev) != 0) {
+        fprintf(stderr, "Cannot initialize libevdev from this device (%s): skipping.\n", sysfs_entry);
+        return NULL;
+    }
+
+    if (strcmp(libevdev_get_name(dev), filters->name) != 0) {
+        return NULL;
+    }
+
+    if (libevdev_grab(dev, LIBEVDEV_GRAB) != 0) {
+        fprintf(stderr, "Unable to grab the device: skipping.\n");
+        return NULL;
+    }
+
+    return 0;
+}
+
+static pthread_mutex_t input_acquire_mutex = PTHREAD_MUTEX_INITIALIZER;
 
 void *input_dev_thread_func(void *ptr) {
-    input_dev_t *out_dev = (input_dev_t*)ptr;
+    input_dev_t *in_dev = (input_dev_t*)ptr;
+
+    struct libevdev* dev = NULL;
 
     for (;;) {
-        const uint32_t flags = out_dev->crtl_flags;
+        const uint32_t flags = in_dev->crtl_flags;
         if (flags & INPUT_DEV_CTRL_FLAG_EXIT) {
-            out_dev->crtl_flags &= ~INPUT_DEV_CTRL_FLAG_EXIT;
+            in_dev->crtl_flags &= ~INPUT_DEV_CTRL_FLAG_EXIT;
             break;
         }
 
+        // clean up from previous iteration
+        if (dev != NULL) {
+            libevdev_free(dev);
+            dev = NULL;
+        }
+
         const int input_acquire_lock_result = pthread_mutex_lock(&input_acquire_mutex);
         if (input_acquire_lock_result != 0) {
+            fprintf(stderr, "Cannot lock input mutex: %d, will retry later...\n", input_acquire_lock_result);
+            usleep(250000);
             continue;
         }
 
         char path[512] = "\0";
-        const char *input_path = "/sys/class/input/";
         
         DIR *d;
         struct dirent *dir;
@@ -39,39 +76,34 @@ void *input_dev_thread_func(void *ptr) {
             while ((dir = readdir(d)) != NULL) {
                 if (dir->d_name[0] == '.') {
                     continue;
+                } else if (dir->d_name[0] == 'b') { // by-id
+                    continue;
+                } else if (dir->d_name[0] == 'j') { // js-0
+                    continue;
                 }
 
                 sprintf(path, "%s%s", input_path, dir->d_name);
 
-                printf("device: %s\n", path);
-
-                char name[510] = "\0";
-
-                char name_path[512] = "\0";
-                sprintf(name_path, "%s/device/name", path);
-
-                FILE* n = fopen(name_path, "r");
-                if (n == NULL) {
-                    fprintf(stderr, "    name: [ERROR]: %s\n", name_path);
-                    continue;
+                if (ev_matches(path, in_dev->ev_filters) != NULL) {
+                    printf("Opened device %s\n    name: %s", path, libevdev_get_name(dev));
+                    break;
                 }
-
-                fseek(n, 0L, SEEK_END);
-                const size_t name_length = ftell(n);
-                fseek(n, 0L, SEEK_SET);
-                fread(name, 1, name_length, n);
-                fclose(n);
-                printf("    name: %s\n", name);
             }
             closedir(d);
         }
 
         pthread_mutex_unlock(&input_acquire_mutex);
 
+        if (dev == NULL) {
+            usleep(250000);
+            continue;
+        }
+
         for (;;) {
             // TODO: do the required
+            //process_events(dev);
 
-            const uint32_t flags = out_dev->crtl_flags;
+            const uint32_t flags = in_dev->crtl_flags;
             if (flags & INPUT_DEV_CTRL_FLAG_EXIT) {
                 break;
             }

input_dev.h

@@ -9,9 +9,20 @@ typedef enum input_dev_type {
     input_dev_type_iio,
 } input_dev_type_t;
 
+typedef struct uinput_filters {
+    const char* name;
+} uinput_filters_t;
+
+typedef struct iio_filters {
+    const char* name;
+} iio_filters_t;
+
 typedef struct input_dev {
     input_dev_type_t dev_type;
 
+    const uinput_filters_t* ev_filters;
+    const iio_filters_t* iio_filters;
+
     volatile uint32_t crtl_flags;
 } input_dev_t;
 

main.c

@@ -6,36 +6,56 @@
 ev_queue_t imu_ev;
 ev_queue_t gamepad_ev;
 
-output_dev_t out_imu_dev = {
+static output_dev_t out_imu_dev = {
   .fd = -1,
   .crtl_flags = 0x00000000U,
   .queue = &imu_ev,
 };
 
-output_dev_t out_gamepadd_dev = {
+static output_dev_t out_gamepadd_dev = {
   .fd = -1,
   .crtl_flags = 0x00000000U,
   .queue = &gamepad_ev,
 };
 
-input_dev_t in_asus_kb_1_dev = {
-  .dev_type = input_dev_type_uinput,
-  .crtl_flags = 0x00000000U,
+static uinput_filters_t in_asus_kb_1_filters = {
+  .name = "Asus Keyboard",
 };
 
-input_dev_t in_asus_kb_2_dev = {
+static input_dev_t in_asus_kb_1_dev = {
   .dev_type = input_dev_type_uinput,
   .crtl_flags = 0x00000000U,
+  .ev_filters = &in_asus_kb_1_filters,
 };
 
-input_dev_t in_asus_kb_3_dev = {
-  .dev_type = input_dev_type_uinput,
-  .crtl_flags = 0x00000000U,
+static uinput_filters_t in_asus_kb_2_filters = {
+  .name = "Asus Keyboard",
 };
 
-input_dev_t in_xbox_dev = {
+static input_dev_t in_asus_kb_2_dev = {
   .dev_type = input_dev_type_uinput,
   .crtl_flags = 0x00000000U,
+  .ev_filters = &in_asus_kb_2_filters,
+};
+
+static uinput_filters_t in_asus_kb_3_filters = {
+  .name = "Asus Keyboard",
+};
+
+static input_dev_t in_asus_kb_3_dev = {
+  .dev_type = input_dev_type_uinput,
+  .crtl_flags = 0x00000000U,
+  .ev_filters = &in_asus_kb_3_filters,
+};
+
+static uinput_filters_t in_xbox_filters = {
+  .name = "Microsoft X-Box 360 pad 0",
+};
+
+static input_dev_t in_xbox_dev = {
+  .dev_type = input_dev_type_uinput,
+  .crtl_flags = 0x00000000U,
+  .ev_filters = &in_xbox_filters,
 };
 
 void request_termination() {
@@ -57,7 +77,6 @@ void sig_handler(int signo)
 }
 
 int main(int argc, char ** argv) {
-  
   out_imu_dev.fd = create_output_dev("/dev/uinput", "Virtual IMU - ROGueENEMY", output_dev_imu);
   if (out_imu_dev.fd < 0) {
     // TODO: free(imu_dev.events_list);

rogue_enemy.h

@@ -12,8 +12,12 @@
 #include <sys/time.h>
 #include <sys/ipc.h>
 #include <sys/sem.h>
+#include <sys/stat.h>
+
 
 #include <linux/uinput.h>
 #include <linux/input.h>
 
 #include <pthread.h>
+
+#include <libevdev-1.0/libevdev/libevdev.h>