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


#define BUF_LEN (10 * (sizeof(struct inotify_event) + NAME_MAX + 1))

char buffer[BUF_LEN];


void display_inotify_event(struct inotify_event * e) {

	printf("inotify_event wd=%d\n", e->wd);

	// che tipo di evento su file è accaduto?

	if (e->mask & IN_ACCESS) {
		printf("IN_ACCESS [read()]\n");
	}
	if (e->mask & IN_ATTRIB) {
		printf("IN_ATTRIB\n");
	}
	if (e->mask & IN_CLOSE_NOWRITE) {
		printf("IN_CLOSE_NOWRITE\n");
	}
	if (e->mask & IN_CLOSE_WRITE) {
		printf("IN_CLOSE_WRITE\n");
	}
	if (e->mask & IN_CREATE) {
		printf("IN_CREATE\n");
	}
	if (e->mask & IN_DELETE) {
		printf("IN_DELETE\n");
	}
	if (e->mask & IN_DELETE_SELF) {
		printf("IN_DELETE_SELF\n");
	}
	if (e->mask & IN_MODIFY) {
		printf("IN_MODIFY\n");
	}
	if (e->mask & IN_OPEN) {
		printf("IN_OPEN\n");
	}

	if (e->len > 0) {
		printf("filename = %s\n", e->name);
	} else {
		printf("filename non specificato perchè è il file che sto monitorando\n");
	}


}


int main() {

	int inotify_fd;
	char * dir_name = ".";
	int wd;

	inotify_fd = inotify_init();
	if (inotify_fd == -1) {
		perror("inotify_init");
		exit(1);
	}

	wd = inotify_add_watch(inotify_fd, dir_name, IN_ALL_EVENTS);
	if (wd == -1) {
		perror("inotify_add_watch");
		exit(1);
	}

	int bytes_read;
	char * p;

	while (1) {

		bytes_read = read(inotify_fd, buffer, BUF_LEN);

		if (bytes_read == -1) {
			perror("read");
			exit(1);
		}

		printf("read returns %d bytes\n", bytes_read);

		for (p = buffer; p < buffer + bytes_read; ) {
			struct inotify_event * event;

			event = (struct inotify_event *) p;

			display_inotify_event(event);

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

		}

	}


}