LinuxでカメラのIDと名前を取得するコード

udev-get-camera-list.c

// Author : Katsuyoshi Hotta
// sudo apt-get install libudev
// udevadm info --query=all --name=/dev/video0

#include <stdio.h>
#include <unistd.h>
#include <libudev.h>

int main()
{
	struct udev *udev;

	/* create udev object */
	udev = udev_new();
	if (!udev) {
		fprintf(stderr, "Can't create udev\n");
		return 1;
	}

	/* Create a list of the devices in the 'video4linux' subsystem. */
	struct udev_enumerate* enumerate = udev_enumerate_new(udev);
	udev_enumerate_scan_devices(enumerate);
	struct udev_list_entry* devices = udev_enumerate_get_list_entry(enumerate);
	struct udev_list_entry* dev_list_entry;

	//Device ID
	static int device_id = 0;

	//Search camera devices
	udev_list_entry_foreach(dev_list_entry, devices)
	{
		const char * name = udev_list_entry_get_name(dev_list_entry);
		struct udev_device * device = udev_device_new_from_syspath(udev, name);
		const char * subsystem = udev_device_get_subsystem(device);

		if (strcmp(subsystem, "video4linux") == 0) {
			// const char  * vendor_id;
			// const char  * product_id;
			// const char  * serial_id;
			const char  * device_name;

			//Search camera properties
			struct udev_list_entry * properties = udev_device_get_properties_list_entry(device);
			struct udev_list_entry * property;
			udev_list_entry_foreach(property, properties) {

				//Get camera propertiy name
				const char * name = udev_list_entry_get_name(property);

				// if(strcmp(name,"ID_VENDOR_ID")==0){
				// 	vendor_id = udev_list_entry_get_value(property);
				// 	printf("%s\n",vendor_id);
				// }

				// if(strcmp(name,"ID_MODEL_ID")==0){
				// 	product_id = udev_list_entry_get_value(property);
				// 	printf("%s\n",product_id);
				// }

				// if(strcmp(name,"ID_SERIAL")==0){
				// 	serial_id = udev_list_entry_get_value(property);
				// 	printf("%s\n",serial_id);
				// }

				//Get camera name
				if (strcmp(name, "ID_V4L_PRODUCT") == 0) {
					device_name = udev_list_entry_get_value(property);
				}
			}

			printf("%d : %s\n", device_id, device_name);

			printf("---\n");

			device_id++;
		}
	}

	/* Free the enumerator object */
	udev_enumerate_unref(enumerate);
	udev_unref(udev);
	return 0;
}