GFileMonitor sample application. Watches the specified path, registers events and prints it on the screen.

gistfile1.c

#include <glib.h>
#include <gio/gio.h>
#include <string.h>

static GMainLoop *gMainLoop = NULL;

char *
decode (GFileMonitorEvent ev)
{
    char *fmt = g_malloc0 (1024);
    int caret = 0;

#define dc(x)  \
    case G_FILE_MONITOR_EVENT_##x: \
        strcat(fmt, #x); \
        caret += strlen(#x); \
        fmt[caret] = ':'; \
        break;

    switch (ev) {
        dc(CHANGED);
        dc(CHANGES_DONE_HINT);
        dc(DELETED);
        dc(CREATED);
        dc(ATTRIBUTE_CHANGED);
        dc(PRE_UNMOUNT);
        dc(UNMOUNTED);
        dc(MOVED);
    }
#undef dc

    return fmt;
}

void
callback (GFileMonitor      *mon,
          GFile             *first,
          GFile             *second,
          GFileMonitorEvent  event,
          gpointer           udata)
{
    char *msg = decode (event);
   
#define fn(x) ((x) ? g_file_get_basename (x) : "--")
    g_printf ("Received event %s (code %d), first file \"%s\", second file \"%s\"\n",
              msg,
              event,
              fn(first),
              fn(second));
#undef fn

    g_free (msg);
}

int
main (int argc, char *argv[])
{
    GFile *file;
    GFileMonitor *mon;

    if (argc < 2) {
        g_printf ("No!");
        return 1;
    }

    g_type_init ();

    file = g_file_new_for_path (argv[1]);
    g_assert (file != NULL);

    mon = g_file_monitor (file, G_FILE_MONITOR_SEND_MOVED, NULL, NULL);
    g_assert (mon != NULL); 

    g_signal_connect (mon, "changed", G_CALLBACK (callback), NULL);
    
    gMainLoop = g_main_loop_new (NULL, FALSE);
    g_main_loop_run (gMainLoop);

    g_object_unref (mon);

    return 0;
}