# -*- tcl -*-

cd /u/ian/things/Bessar/trains
exec xsetroot -solid #00000f

set trainscmd {
    set -x
    savelog -c 7 bessar.log
#    (set -ex
    cd /u/ian/things/trains-bessar/hostside
    ./stopgap-controller | ./gui-displayer -
#    ) 2>&1 | tee bessar.log
}

proc trains_start {} {
    global trainsf trainscmd
    trains_stop
    set cmdl [list sh -ec $trainscmd 2>@ stderr]
    set trainsf [open |$cmdl w]
    fconfigure $trainsf -buffering none -blocking no
}

proc tw {s} {
    global trainsf
    if {![info exists trainsf]} return
    if {[catch {
	puts $trainsf $s
    } emsg]} {
	puts stderr "tw: $emsg"
	trains_stop
    }
}

proc okagain {} {
    global okagain
    set okagain 1
}

proc trains_stop {} {
    global trainsf okagain
    if {![info exists trainsf]} return
    catch { close $trainsf }
    unset trainsf
    after 3000 okagain
    vwait okagain
}