inotify系列函数来监控文件事件

Posted 2021-09-06 sesiria

在实际开发中有时候回遇到许多文件的操作，或者需要对文件事件进行排查。。

可以使用inotify函数来完成这项工作

代码如下：

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/inotify.h>

#define EVENT_SIZE      (sizeof (struct inotify_event))
#define BUF_LEN         (10 * (EVENT_SIZE + 256))

static const char * filetype[] = {"directory", "file"};

static void
displayInotifyEvent(struct inotify_event * event)
{
    const char * type = (event->mask & IN_ISDIR) ? filetype[0] : filetype[1];
    if(event->len) {
        if(event->mask & IN_CREATE) {
            printf("The %s %s was created.\\n", type, event->name);
        }
        else if(event->mask & IN_DELETE) {
            printf("The %s %s was deleted.\\n", type, event->name);
        }
        else if(event->mask & IN_MODIFY) {
            printf("The %s %s was modified.\\n", type, event->name);
        }
    }    
}

int main(int argc, char *argv[])
{
    int length, i = 0;
    int fd;
    int wd;
    char buffer[BUF_LEN] __attribute__((aligned(8)));
    
    const char * type;
    char *p;
    struct inotify_event *event;

    if(argc < 2) {
        printf("usage: %s [pathname...]\\n", argv[0]);
        exit(EXIT_SUCCESS);
    } 

    printf("%s %s\\n", filetype[0], filetype[1]);

    fd = inotify_init();

    if(fd < 0) {
        perror("inotify_init");
    }

    wd = inotify_add_watch(fd, argv[1],
                           IN_MODIFY | IN_CREATE | IN_DELETE);
    if(wd == -1) {
        perror("error inotify_add_watch\\n");
        exit(EXIT_FAILURE);
    }

    for(;;) {
        length = read(fd, buffer, BUF_LEN);

        if(length < 0) {
            perror("read\\n");
            exit(EXIT_FAILURE);
        }
        for(p = buffer; p < buffer + length;) {
            event = (struct inotify_event *) p;
            displayInotifyEvent(event);

            p += sizeof(struct inotify_event) + event->len;
        }
    }

    inotify_rm_watch(fd, wd);
    close(fd);

    exit(EXIT_SUCCESS);
}

使用方法：