以函数的形式实现,并用建立新的线程方式监测/sys/class/gpio/gpio2是否有中断发生C语言，中断触发条件可以选rising，fallin，both

以下是一个以函数形式实现并用新线程监测GPIO中断的示例代码：

#include <stdio.h>
#include <stdlib.h>
#include <pthread.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/select.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <sys/time.h>

#define GPIO_PIN 2
#define GPIO_DIR "/sys/class/gpio/gpio2/"
#define GPIO_VALUE GPIO_DIR "value"
#define GPIO_EDGE GPIO_DIR "edge"

void *gpio_monitor(void *arg) {
    fd_set fds;
    struct timeval tv;
    int fd, ret, val;
    char buf[8];

    fd = open(GPIO_VALUE, O_RDONLY);
    if (fd < 0) {
        perror("open");
        return NULL;
    }

    while (1) {
        FD_ZERO(&fds);
        FD_SET(fd, &fds);
        tv.tv_sec = 1;
        tv.tv_usec = 0;

        ret = select(fd + 1, &fds, NULL, NULL, &tv);
        if (ret < 0) {
            perror("select");
            break;
        } else if (ret == 0) {
            continue;
        } else {
            lseek(fd, 0, SEEK_SET);
            ret = read(fd, buf, sizeof(buf));
            if (ret < 0) {
                perror("read");
                break;
            }

            val = atoi(buf);
            printf("GPIO value: %d\n", val);
        }
    }

    close(fd);
    return NULL;
}

int gpio_init() {
    int fd;
    char buf[8];

    fd = open(GPIO_DIR "direction", O_WRONLY);
    if (fd < 0) {
        perror("open");
        return -1;
    }

    sprintf(buf, "in");
    write(fd, buf, sizeof(buf));
    close(fd);

    fd = open(GPIO_EDGE, O_WRONLY);
    if (fd < 0) {
        perror("open");
        return -1;
    }

    sprintf(buf, "both");
    write(fd, buf, sizeof(buf));
    close(fd);

    return 0;
}

int gpio_start_monitor() {
    pthread_t tid;
    int ret;

    ret = pthread_create(&tid, NULL, gpio_monitor, NULL);
    if (ret != 0) {
        perror("pthread_create");
        return -1;
    }

    return 0;
}

int main() {
    int ret;

    ret = gpio_init();
    if (ret != 0) {
        printf("Failed to initialize GPIO\n");
        return -1;
    }

    ret = gpio_start_monitor();
    if (ret != 0) {
        printf("Failed to start GPIO monitor\n");
        return -1;
    }

    printf("GPIO monitor started\n");

    while (1) {
        sleep(1);
    }

    return 0;
}

该程序将GPIO2作为输入引脚，设置其中断触发条件为上升沿、下降沿和边沿，然后在一个新线程中监测GPIO的值。当GPIO的值发生变化时，该程序会输出变化后的值。注意，该程序仅在Linux系统下运行。