tv xkiller: init

tv/5pkgs/simple/xkiller.nix

@@ -0,0 +1,25 @@
+{ pkgs }:
+pkgs.writeDash "xkiller" ''
+  set -efu
+  exec >&2
+  ${pkgs.iproute}/bin/ss -lp src unix:/tmp/.X11-unix/X* |
+  ${pkgs.gnused}/bin/sed -n '
+    s|.*/tmp/.X11-unix/X\([0-9]\+\)\>.*("X[^"]*",pid=\([0-9]\+\)\>.*|\1 \2|p
+  ' |
+  while read -r display pid; do
+    {
+      exit_code=$(
+        DISPLAY=:$display ${pkgs.coreutils}/bin/timeout 1 \
+            ${pkgs.xorg.xset}/bin/xset q >/dev/null 2>&1 &&
+            echo 0 || echo $?
+      )
+      if test $exit_code = 124; then
+        echo "X on display :$display is locked up; killing PID $pid..."
+        ${pkgs.coreutils}/bin/kill -SIGKILL "$pid"
+      else
+        echo "X on display :$display is healthy"
+      fi
+    } &
+  done
+  wait
+''