Ticket #9834: modified_time_monitor.cpp

#include <errno.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>

#include <Looper.h>
#include <Node.h>
#include <NodeMonitor.h>


struct Looper : BLooper {
    Looper(const char* path)
        :
        BLooper(),
        fPath(path)
    {
    }

    virtual void MessageReceived(BMessage* message)
    {
        if (message->what != B_NODE_MONITOR)
            return BLooper::MessageReceived(message);

        if (message->GetInt32("opcode", 0) == B_STAT_CHANGED
            && (message->GetInt32("fields", 0) & B_STAT_MODIFICATION_TIME)
                != 0) {
            struct stat st;
            if (lstat(fPath, &st) == 0) {
                printf("node %" B_PRIdDEV ":%" B_PRIdINO " modification time "
                    "changed: %ld.%ld\n", st.st_dev, st.st_ino,
                    (long)st.st_mtim.tv_sec, (long)st.st_mtim.tv_nsec);
            }
        }
    }

private:
    const char* fPath;
};


int
main(int argc, const char* const* argv)
{
    if (argc < 2) {
        fprintf(stderr, "Usage: %s <path>\n", argv[0]);
        return 1;
    }

    const char* path = argv[1];

    struct stat st;
    if (lstat(path, &st) != 0) {
        fprintf(stderr, "Error: Failed to stat() \"%s\": %s\n", path,
            strerror(errno));
        return 1;
    }

    Looper* looper = new Looper(path);
    thread_id thread = looper->Run();

    node_ref nodeRef(st.st_dev, st.st_ino);
    status_t error = watch_node(&nodeRef, B_WATCH_STAT, looper);
    if (error != B_OK) {
        fprintf(stderr, "Error: Failed to start watching node: %s\n",
            strerror(error));
        return 1;
    }

    wait_for_thread(thread, NULL);

    return 0;
}