Inotify example

inotify_example.c

#include <stdio.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/types.h>
#include <sys/inotify.h>
#include <unistd.h>
#include <limits.h>
#include <string.h>
#define EVENT_SIZE  ( sizeof (struct inotify_event) )
#define EVENT_BUF_LEN     ( 1024 * ( EVENT_SIZE + 16 ) )
#define BUF_LEN (10 * (sizeof(struct inotify_event) + NAME_MAX + 1))

int main() {

    char *ptr, *ptr2;
    char *bufPtr, *bufPtr2;
    ssize_t numRead;
    int inotifyFd, wd, wd2;
    char buf[BUF_LEN] __attribute__ ((aligned(8)));
    struct inotify_event* event;
    char *p;
    
    inotifyFd = inotify_init();
    
    printf("inotify started\n");
    long size = pathconf(".", _PC_PATH_MAX);
    if ((bufPtr = (char *)malloc((size_t)size)) != NULL) {
        ptr = getcwd(bufPtr, (size_t)size);
    }
    printf("added notify to %s\n", bufPtr);
    size = pathconf("..", _PC_PATH_MAX);
    if ((bufPtr2 = (char *)malloc((size_t)size+3)) != NULL) {
        ptr2 = strcat(getcwd(bufPtr2, (size_t)size), "/..");
    }
    printf("added notify to %s\n", bufPtr2);
    wd = inotify_add_watch( inotifyFd, bufPtr, IN_ALL_EVENTS );

    wd2 = inotify_add_watch( inotifyFd, bufPtr2, IN_ALL_EVENTS );

    for(;;) {
        numRead = read(inotifyFd, buf, BUF_LEN);
        if (numRead == 0) {
            printf("read() from inotify fd returned 0!\n");
            exit(1);
        }

        for (p = buf; p < buf + numRead; ) {
            event = (struct inotify_event *) p;
            if(event->wd == wd) {
                if(event->mask & IN_OPEN) {
                    printf("event from current directory: %d\n", event->mask & IN_OPEN);

                }
            }
            else if(event->wd == wd2) {
                if(event->mask & IN_OPEN) {
                    printf("event from parent: %d\n", event->mask & IN_OPEN);

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

    return 0;
}