C工作线程轮询任务完成状态文件描述符

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>

int main() {
    int fd = open("status_file.txt", O_RDONLY | O_NONBLOCK);
    if (fd == -1) {
        perror("open");
        exit(EXIT_FAILURE);
    }

    while (1) {
        char buffer[1024];
        ssize_t bytes_read = read(fd, buffer, sizeof(buffer));
        if (bytes_read > 0) {
            // 处理读取到的数据
            printf("Data received: %.*s\n", (int)bytes_read, buffer);
        } else if (bytes_read == 0) {
            // 文件描述符关闭
            printf("File descriptor closed\n");
            break;
        } else if (errno != EAGAIN && errno != EWOULDBLOCK) {
            // 其他错误
            perror("read");
            break;
        }
        // 短暂休眠以避免忙等待
        usleep(1000);
    }

    close(fd);
    return 0;
}