linux查询video设备类型

想查询 dev/video的类型，找不到命令，闲的蛋疼留个模版

用的时候把video列表写进solve前的 dev_list即可

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <assert.h>

#include <fcntl.h>              /* low-level i/o */
#include <unistd.h>
#include <errno.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/time.h>
#include <sys/mman.h>
#include <sys/ioctl.h>
#include <asm/types.h>

#include <linux/videodev2.h>

int device_open(char *dev_name)
{
    struct stat st;
    if (-1 == stat(dev_name, &st)) 
    {
        fprintf(stderr, "Cannot identify '%s': %d, %s\n", dev_name, errno, strerror(errno));
        // exit(EXIT_FAILURE);
    }
    if (!S_ISCHR(st.st_mode)) 
    {
        fprintf(stderr, "%s is no device\n", dev_name);
        // exit(EXIT_FAILURE);
    }
    int fd = open(dev_name, O_RDWR /* required */ | O_NONBLOCK, 0);
    if (-1 == fd) 
    {
        fprintf(stderr, "Cannot open '%s': %d, %s\n", dev_name, errno, strerror(errno));
        // exit(EXIT_FAILURE);
    }
    printf("%s %d : Open %s successfully. fd = %d\n", __func__, __LINE__, dev_name, fd);
	return fd;
}

int device_close(int fd)
{
    if (-1 == close(fd))
    {
    	printf("\tdevice close failed.\n");
    	// exit(EXIT_FAILURE);
    }
    else
    {
    	printf("%s %d : devices close successfully\n", __func__, __LINE__);
    }
	return 0;
}

int device_query(char *dev_name, int fd)
{
	struct v4l2_capability cap;
	memset(&cap, 0, sizeof(cap));
    if (-1 == ioctl(fd, VIDIOC_QUERYCAP, &cap)) // query v4l2-devices's capability
    {
        if (EINVAL == errno) 
        {
            fprintf(stderr, "%s is no V4L2 device\n", dev_name);
            // exit(EXIT_FAILURE);
        } 
        else 
        {
        	return 0;
        	printf("\tvideo ioctl_querycap failed.\n");
            // exit(EXIT_FAILURE);
        }
	}
	else//\tdevice name : %s\n    dev_name, 
	{
		printf("\n\tdriver name : %s\n\tcard name : %s\n\tbus info : %s\n\tdriver version : %u.%u.%u\n\n",
			    cap.driver, cap.card, cap.bus_info,(cap.version >> 16) & 0XFF, (cap.version >> 8) & 0XFF, cap.version & 0XFF);
	}
	return 0;
}

int dev_num = 27;
char dev_list[100][20] = {
	"/dev/video6",	"/dev/video7",	"/dev/video11",	"/dev/video12",	"/dev/video13", // 00 - 04
	"/dev/video14",	"/dev/video15",	"/dev/video16",	"/dev/video17",	"/dev/video18", // 05 - 09
	"/dev/video19",	"/dev/video23",	"/dev/video24",	"/dev/video25",	"/dev/video26", // 10 - 14
	"/dev/video27",	"/dev/video28",	"/dev/video29",	"/dev/video30",	"/dev/video31", // 15 - 19
	"/dev/video32",	"/dev/video33",	"/dev/video34",	"/dev/video36",	"/dev/video37", // 20 - 24
	"/dev/video38",	"/dev/video50"
};

int solve()
{
	int i = 0;
	int dev_start = 0;
	int dev_end = dev_num;
	for( i = dev_start; i < dev_end; ++i)
	{
		int fd = device_open(dev_list[i]);
		device_query(dev_list[i], fd);
		device_close(fd);
	}
	return 0;
}


int main()
{
	printf("\nstart game\n");

	solve();

	printf("\nquit game\n");
	return 0;
}

附 rp5410 video info

/*

start game
	device name :video6 
	driver name : MFC
	card name : decoder
	bus info : 
	driver version : 1.0.0


	device name :video7 
	driver name : MFC
	card name : encoder
	bus info : 
	driver version : 1.0.0


	device name :video11 
	driver name : s5p-jpeg
	card name : s5p-jpeg
	bus info : 
	driver version : 1.0.0


	device name :video12 
	driver name : s5p-jpeg
	card name : s5p-jpeg
	bus info : 
	driver version : 1.0.0


	device name :video13 
	driver name : exynos5-jpeg-hx
	card name : exynos5-jpeg-hx
	bus info : 
	driver version : 1.0.0


	device name :video14 
	driver name : exynos5-jpeg-hx
	card name : exynos5-jpeg-hx
	bus info : 
	driver version : 1.0.0


	device name :video16 
	driver name : s5p-mixer
	card name : mxr0_graph0
	bus info : 0
	driver version : 0.1.0


	device name :video17 
	driver name : s5p-mixer
	card name : mxr0_graph1
	bus info : 1
	driver version : 0.1.0


	device name :video18 
	driver name : s5p-mixer
	card name : mxr1_graph2
	bus info : 2
	driver version : 0.1.0


	device name :video19 
	driver name : s5p-mixer
	card name : mxr1_graph3
	bus info : 3
	driver version : 0.1.0


	device name :video23 
	driver name : exynos-gsc
	card name : exynos-gsc
	bus info : 
	driver version : 3.4.5


	device name :video24 
	driver name : exynos-gsc
	card name : exynos-gsc
	bus info : 
	driver version : 3.4.5


	device name :video26 
	driver name : exynos-gsc
	card name : exynos-gsc
	bus info : 
	driver version : 3.4.5


	device name :video27 
	driver name : exynos-gsc
	card name : exynos-gsc
	bus info : 
	driver version : 3.4.5


	device name :video29 
	driver name : exynos-gsc
	card name : exynos-gsc
	bus info : 
	driver version : 3.4.5


	device name :video30 
	driver name : exynos-gsc
	card name : exynos-gsc
	bus info : 
	driver version : 3.4.5


	device name :video32 
	driver name : exynos-gsc
	card name : exynos-gsc
	bus info : 
	driver version : 3.4.5


	device name :video33 
	driver name : exynos-gsc
	card name : exynos-gsc
	bus info : 
	driver version : 3.4.5


	device name :video50 
	driver name : exynos5-scaler
	card name : exynos5-scaler
	bus info : 
	driver version : 3.4.5



quit game


*/