Question

我正在编写一个程序来监视何时使用C ++将文件写入Mac OSX文件系统。我直接调用fsevents，这样我就可以获得将文件写入文件系统的进程的PID。

当我在用户名下运行程序时，我收到错误＆＃34; kevent寄存器：错误的文件描述符＆＃34;属于我的计划的第43行。如果我以sudo身份运行它，程序运行时没有错误，但从未收到写入文件的通知。我通过发出：echo "blah" >> /tmp/1234来测试它。

代码：

#include "fcntl.h"      //for O_RDONLY
#include "errno.h"      //for errno
#include "stdio.h"    //for fprintf()
#include "string.h"     //for strerror()
#include "stdlib.h"     //for EXIT_SUCCESS
#include "sys/event.h"  //for kqueue() & more
#include "unistd.h"     //for close()
#include <err.h>
#include <sys/ioctl.h>  //for iotcl control working with fsevents

int main(int argc, char *argv[])
{
    printf("Exectuted");

    struct kevent kev_set;  /* Event we want to monitor */
    struct kevent kev_retr; /* Event triggered */
    int kq, fd, ret;

    // directory to monitor, NO checks for errors here
    fd = open ("/dev/fsevents", O_RDONLY);

    //if (ioctl(fd, TIOCMGET, &status) >= 0)
    //    err(EXIT_FAILURE, "TIOCMGET failed:");

    kq = kqueue();
    if (kq  == -1)
        err(EXIT_FAILURE, "kqueue() failed");

    /* Initialize kevent structure. */
        EV_SET(&kev_set, fd, EVFILT_VNODE, EV_ADD | EV_CLEAR, NOTE_WRITE, 0, NULL);

        /* Attach event to the  kqueue. */
        ret = kevent(kq, &kev_set, 1, NULL, 0, NULL);
        if (ret == -1)
            err(EXIT_FAILURE, "kevent register");

    for (;;) {
        /* Sleep until something happens */
        printf("Starting loop\n");
        ret = kevent(kq, NULL, 0, &kev_retr, 1, NULL);
        if (ret == -1)
        {
            err(EXIT_FAILURE, "kevent wait");
        }
        else if (ret > 0) {
                 printf("Something was written: ");
                }
    }

    close(fd);

}

输出：

$ ./fsmon-test 
fsmon-test: kevent register: Bad file descriptor

提前谢谢！

Mac OSX Filesystem修改程序。错误：＆＃34; kevent注册：错误的文件描述符＆＃34;

0 个答案: