Detects change of ~/.plan

changeofplan.cpp

/*
 * Copyright (c) 2009 Gaute Hope <eg@gaute.vetsj.com>
 * Distributed under the terms of the GNU General Public Licence v2
 *
 * Waits for change of ~/.plan
 *
 */

# include <iostream>
# include <sys/inotify.h>
# include <cstdlib>
# include <cstring>

using namespace std;

const char * get_event_name (uint32_t);

int main () {
    int ifd = inotify_init ();

    char *home = getenv ("HOME");
    int dir = inotify_add_watch (ifd, home, IN_CLOSE_WRITE | IN_DELETE | IN_MOVED_TO);
    if (dir == -1) {
        close (ifd);
        exit (1);
    }

    const int event_size = sizeof (inotify_event);

    /* buffer of max 1024 events.
     *
     * the string inotify_event->name, if present,
     * increases the size of the event structure.
     */
    const int buf_len = 1024 * (event_size);

    while (1) {
        char buf[buf_len];

        /* read() reads in events as long as there
         * is space in buf[], then continues.
         *
         * but it will also block when there are no events pending
         * and buf[] is empty, otherwise continue.
         */
        int len = read (ifd, buf, buf_len);

        if (len < 1) {
            close (ifd);
            exit (1);
        }

        int i = 0;
        while (i < len) {
            inotify_event *e = reinterpret_cast<inotify_event *> (&buf[i]);

            if (e->len && (strcmp (e->name, ".plan") == 0))
                cout << get_event_name (e->mask) << ":: CHANGE OF PLAN!" << endl;

            i += event_size + e->len;
        }
    }
    close (ifd);
    exit (0);
}

const char * get_event_name (uint32_t mask) {
    if (mask & IN_ACCESS) return "IN_ACCESS";
    if (mask & IN_ATTRIB) return "IN_ATTRIB";
    if (mask & IN_CLOSE_WRITE) return "IN_CLOSE_WRITE";
    if (mask & IN_CLOSE_NOWRITE) return "IN_CLOSE_NOWRITE";
    if (mask & IN_CREATE) return "IN_CREATE";
    if (mask & IN_DELETE) return "IN_DELETE";
    if (mask & IN_DELETE_SELF) return "IN_DELETE_SELF";
    if (mask & IN_MODIFY) return "IN_MODIFY";
    if (mask & IN_MOVE_SELF) return "IN_MOVE_SELF";
    if (mask & IN_MOVED_FROM) return "IN_MOVED_FROM";
    if (mask & IN_MOVED_TO) return "IN_MOVED_TO";
    if (mask & IN_OPEN) return "IN_OPEN";

    if (mask & IN_IGNORED) return "IN_IGNORED";
    if (mask & IN_ISDIR) return "IN_ISDIR";
    if (mask & IN_Q_OVERFLOW) return "IN_Q_OVERFLOW";
    if (mask & IN_UNMOUNT) return "IN_UNMOUNT";
}