@User as far as i know, redirecting xschem's I/O to /dev/null is also ok, in this case i suggest launching xschem with the '-r' option. If tclreadline package is installed xschem uses readline. However it's better to disable if you redirect to /dev/null.

-r  --no_readline    Start without the tclreadline package ( this is

necessary if stdin and stdout are to be redirected

for example to /dev/null).

Thank you!