On Fri, Apr 06, 2018 at 06:45:20PM +0200, Mikhail Morfikov wrote: > Basically even the standard "exec ..." in the /etc/X11/Xsession file (with > changed $ERRFILE) works fine, but I have to "cat" the FIFO device first > (without > using systemd). The same with your exec command -- there's no difference in > working.
Opening one end of a FIFO blocks until the OTHER end is also opened. This is why the first process to open the FIFO should be launched in the background (it is going to block), if both ends are coming from the same parent script. I'm assuming that when you speak of "cat" you mean a process that opens the FIFO for reading.
