I am also interested in the response to that question.
From the previous thread, it would seem you could:
- touch the file of interest through a regular call to the filesystem
- implement for instance the following callback in your FUSE code:
int (*utimens) (const char *, const struct timespec tv[2]);
I could just write the code and see if it works, but maybe somebody
could say if this is the kind of trick that would do the job?
thanks!
charles
On May 24, 2007, at 10:30 AM, Hamish wrote:
>
>
> Hi,
>
> The changelog for MacFUSE mentions that as of release 0.2.0, MacFUSE
> contains support for the kqueue/kevent notification mechanism. Given
> that any libc program can use this mechanism to listen for filesystem
> events, I take this to mean that MacFUSE now has support for causing
> those events to be generated -- i.e., a MacFUSE file system daemon can
> cause notifications to be received by any other program listening for
> EVFILT_VNODE events for a descriptor on that file system.
>
> The changelog recommends reading the man page for kqueue(2), but as
> far as I can tell this only details the mechanism for user programs to
> set themselves up to receive events, rather than to generate them.
> (Indeed, one would expect a FUSE-specific mechanism for generating
> events on a FUSE filesystem.)
>
> To illustrate what I am trying to achieve: consider a simple
> filesystem containing a single file whose name is the current time
> (for simplicity's sake, just hours and minutes without a colon). To
> find out the time, the user can just check the contents of the
> directory at the mount point. But the time appearing in a Finder
> window will be the time at which that window was opened, rather than
> the present time. To keep it updated, you would need to arrange for a
> kevent to be sent every minute, e.g.:
>
> // Assume callbacks exist for returning the value of the following
> string
> // as the sole filename residing at the root of the filesystem:
>
> static char *clock_string = "0000";
>
> int main(int argc, char **argv)
> {
> pid_t pid = fork();
>
> if (pid < 0)
> return pid;
> else if (pid > 0)
> return fuse_main(argc, argv, &callbacks, NULL);
> else
> {
> struct timeval tp;
> char *old_clock_path = "/0000";
> while (gettimeofday(&tp) > -1)
> {
> usleep((60 - (tp.tv_sec % 60)) * 1000000 - tp.tv_usec);
> strncpy(&old_clock_path[1], clock_string, 4);
> struct tm *info = localtime(tp->tv_sec);
> sprintf(clock_string, "%2d%2d", info->tm_hour, info-
>> tm_min);
> fuse_notify(old_clock_path, NOTE_RENAME);
> }
> return 0;
> }
> }
>
> Perhaps one would also have to notify of changes to the parent
> directory. Anyway, the main thing I'm looking for is the functionality
> of fuse_notify() above -- i.e. a "push" function rather than the
> "pull" functions passed to fuse_main(). Does such functionality exist
> in MacFUSE?
>
> I have searched the archives and found a thread in which the same
> question was asked, and Amit replied that it was theoretically
> possible, but did not expand upon that:
>
> http://groups.google.com/group/macfuse-devel/browse_thread/thread/
> de16dc338835b7b3/cc3f636d17d9e180
>
> Many thanks,
> Hamish
>
>
> >
--
Xgrid-at-Stanford
Help science move fast forward:
http://cmgm.stanford.edu/~cparnot/xgrid-stanford
Charles Parnot
[EMAIL PROTECTED]
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups
"macfuse-devel" group.
To post to this group, send email to [email protected]
To unsubscribe from this group, send email to [EMAIL PROTECTED]
For more options, visit this group at
http://groups.google.com/group/macfuse-devel?hl=en
-~----------~----~----~----~------~----~------~--~---
