[xmonad] how to redirect dynamicLogXinerama output to a FIFO/named pipe?

Brandon Allbery allbery.b at gmail.com
Thu Jun 28 21:00:35 CEST 2012

On Thu, Jun 21, 2012 at 9:31 AM, Lara Michaels
<laramichaels1978 at yahoo.com>wrote:

> thank you for this, now I no longer get the error message upon starting
> xmonad. However, still nothing gets read by 'tail -f .xmonad-fifo'.

Sorry for the delay on this, things have been "interesting" here of late.

It belatedly occurred to me that this *is* a FIFO, and as such the reader
has to open it first, with O_RDWR (or what Haskell calls ReadWriteMode) or
it won't get hooked up properly.  (This is a POSIXism, and Linux at least
is very strict about it; depending on the kernel version, you may see
ENXDEV ("No such device or address") or what gets "opened" is a dummy node
that will never successfully read or write data.)

> Is there some other way to the dynamicLogXinerama information so that I
> can display it on an applet/appindicator?

dynamicLogXinerama is not very flexible; the documentation notes this, and
suggests an alternative which provides most of the same information while
giving you flexibility

All in all, POSIX FIFOs are remarkably useless (and I'm still amazed POSIX
found a way to make them even less useful than they were originally) and
should probably be avoided.

brandon s allbery                                      allbery.b at gmail.com
wandering unix systems administrator (available)     (412) 475-9364 vm/sms
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://www.haskell.org/pipermail/xmonad/attachments/20120628/b7c43963/attachment.htm>

More information about the xmonad mailing list