/*
 * inotify-watchdir.c
 *
 * Watch a file or directory for changes using inotify
 *
 * Copyright (c) 2008-2009 Tobias Klauser <tklauser@distanz.ch>
 *
 * All rights reserved.
 */

#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <sys/inotify.h>

struct mask2string {
	uint32_t mask;
	const char *desc;
};

static const struct mask2string events[] = {
	{ IN_ACCESS, "ACCESS" },
	{ IN_MODIFY, "MODIFY" },
	{ IN_ATTRIB, "ATTRIB" },
	{ IN_CLOSE_WRITE, "CLOSE_WRITE" },
	{ IN_CLOSE_NOWRITE, "CLOSE_NOWRITE" },
	{ IN_OPEN, "OPEN" },
	{ IN_MOVED_FROM, "MOVED_FROM" },
	{ IN_MOVED_TO, "MOVED_TO" },
	{ IN_CREATE, "CREATE" },
	{ IN_DELETE, "DELETE" },
	{ IN_DELETE_SELF, "DELETE_SELF" },
	{ IN_MOVE_SELF, "MOVE_SELF" },
	{ IN_UNMOUNT, "UNMOUNT" },
	{ IN_Q_OVERFLOW, "Q_OVERFLOW" },
	{ IN_IGNORED, "IGNORED" },
	/* special flags */
	{ IN_ONLYDIR, "ONLYDIR" },
	{ IN_DONT_FOLLOW, "DONT_FOLLOW" },
	{ IN_MASK_ADD, "MASK_ADD" },
	{ IN_ONESHOT, "ONESHOT" },
	/* end of array */
	{ -1, NULL }
};

static void inotify_print_event(struct inotify_event *inev)
{
	int i;

	/* stat? */
	printf("(%s) wd=%04x, cookie=%04x, len=%04x, name=\"%s\" :",
			inev->mask & IN_ISDIR ? "dir" : "file",
			inev->wd, inev->cookie, inev->len,
			inev->len > 0 ? inev->name : "");

	for (i = 0; events[i].desc; i++)
		if (inev->mask & events[i].mask)
			printf(" %s", events[i].desc);

	printf("\n");
}

int main(int argc, char *argv[])
{
	int fd, len;
	int *watches;
	struct inotify_event *inev;
	char buf[1024];

	if (argc < 2) {
		printf("Usage: %s <path> ...\n", *argv);
		exit(EXIT_FAILURE);
	}

	++argv;

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

	watches = malloc((argc - 1) * sizeof(int));
	if (!watches) {
		perror("malloc");
		exit(EXIT_FAILURE);
	}

	while (*argv) {
		*watches = inotify_add_watch(fd, *argv, IN_ALL_EVENTS|IN_UNMOUNT);
		if (*watches < 0) {
			perror("inotify_add_watch");
			exit(EXIT_FAILURE);
		}
		++watches;
		++argv;
	}

	while (1) {
		len = read(fd, buf, sizeof(buf));
		inev = (struct inotify_event *) &buf;
		while (len > 0) {
			inotify_print_event(inev);

			len -= sizeof(struct inotify_event) + inev->len;
			inev = (struct inotify_event *) ((char *) inev
					+ sizeof(struct inotify_event) + inev->len);
		}
	}

	return 0;
}