From 7c4f48df57bf94beba40635c9c8cdc7be18510d8 Mon Sep 17 00:00:00 2001
From: Kolan Sh <mecareful@gmail.com>
Date: Tue, 20 Mar 2012 16:46:24 +0400
Subject: [PATCH 1/2] sudo removed

---
 etc/init.d/snail-watcher                      | 26 ++++++
 etc/init.d/{snail => snail-xserver}           |  9 ++-
 etc/local.d/snail.start                       |  3 -
 usr/local/sbin/snail.install => snail.install |  8 +-
 snail.uninstall                               | 34 ++++++++
 usr/local/bin/nvrun                           | 80 +++++--------------
 usr/local/bin/snail.nvoff                     |  4 -
 usr/local/bin/snail.nvon                      |  4 -
 usr/local/bin/snail.nvrun                     | 16 ----
 usr/local/bin/snail.nvstat                    | 11 ---
 usr/local/sbin/snail.autostop                 | 34 --------
 usr/local/sbin/snail.dmidecode                |  4 -
 usr/local/{bin => sbin}/snail.nv_pwr_off      |  2 +-
 usr/local/{bin => sbin}/snail.nv_pwr_on       |  2 +-
 usr/local/sbin/snail.uninstall                | 18 -----
 usr/local/sbin/snail.watcher                  | 31 +++++++
 16 files changed, 121 insertions(+), 165 deletions(-)
 create mode 100755 etc/init.d/snail-watcher
 rename etc/init.d/{snail => snail-xserver} (80%)
 delete mode 100755 etc/local.d/snail.start
 rename usr/local/sbin/snail.install => snail.install (70%)
 create mode 100755 snail.uninstall
 delete mode 100755 usr/local/bin/snail.nvoff
 delete mode 100755 usr/local/bin/snail.nvon
 delete mode 100755 usr/local/bin/snail.nvrun
 delete mode 100755 usr/local/bin/snail.nvstat
 delete mode 100755 usr/local/sbin/snail.autostop
 delete mode 100755 usr/local/sbin/snail.dmidecode
 rename usr/local/{bin => sbin}/snail.nv_pwr_off (98%)
 rename usr/local/{bin => sbin}/snail.nv_pwr_on (97%)
 delete mode 100755 usr/local/sbin/snail.uninstall
 create mode 100755 usr/local/sbin/snail.watcher

diff --git a/etc/init.d/snail-watcher b/etc/init.d/snail-watcher
new file mode 100755
index 0000000..fa96087
--- /dev/null
+++ b/etc/init.d/snail-watcher
@@ -0,0 +1,26 @@
+#!/sbin/runscript
+
+DAEMON="/usr/local/sbin/snail.watcher"
+DAEMON_ARGS=""
+PIDFILE=/var/run/snail.pid
+PATH=$PATH:/usr/local/bin
+
+depend() {
+        need localmount
+}
+
+start() {
+        ebegin "Starting ${SVCNAME}"
+        start-stop-daemon -m -b --start --exec $DAEMON \
+            --pidfile $PIDFILE \
+            -- $DAEMON_ARGS
+        eend $?
+}
+
+stop() {
+        ebegin "Stopping ${SVCNAME}"
+        start-stop-daemon --stop --exec $DAEMON \
+            --pidfile $PIDFILE
+        eend $?
+}
+
diff --git a/etc/init.d/snail b/etc/init.d/snail-xserver
similarity index 80%
rename from etc/init.d/snail
rename to etc/init.d/snail-xserver
index 56983b4..d258dd1 100755
--- a/etc/init.d/snail
+++ b/etc/init.d/snail-xserver
@@ -15,9 +15,13 @@ start() {
 	export LD_LIBRARY_PATH=/usr/lib/opengl/nvidia/lib:/usr/lib/opengl/nvidia/lib
 	start-stop-daemon --start --quiet --background --pidfile $PIDFILE --exec $DAEMON -- $DAEMON_ARGS
 	status=$?
+	# FIXME: remove --background flag and next cycle
         let i=300
-        while [ 0 -lt $i ]; do snail.nvstat >/dev/null && break; sleep 0.01; let i--; done
-	(nohup snail.autostop &>/dev/null)&
+        while [ 0 -lt $i ]; do
+		[ -f $PIDFILE ] && pgrep -s `cat $PIDFILE` &>/dev/null && break
+		sleep 0.01
+		let i--
+	done
 	eend $status
 }
 
@@ -27,4 +31,3 @@ stop() {
 	snail.nv_pwr_off || eend -1
 	eend $result
 }
-
diff --git a/etc/local.d/snail.start b/etc/local.d/snail.start
deleted file mode 100755
index 99c819c..0000000
--- a/etc/local.d/snail.start
+++ /dev/null
@@ -1,3 +0,0 @@
-# /etc/conf.d/local.start
-
-snail.nv_pwr_off
diff --git a/usr/local/sbin/snail.install b/snail.install
similarity index 70%
rename from usr/local/sbin/snail.install
rename to snail.install
index 2f6511f..7c3d665 100755
--- a/usr/local/sbin/snail.install
+++ b/snail.install
@@ -4,7 +4,7 @@ PREFIX=/usr/local
 
 # Tell the system to use xorg-x11 OpenGL libraries and nVidia GLX extensions
 eselect opengl set xorg-x11
-for arch in 32bit 64bit; do for chip in i915 i965 r300 r600 sw; do sudo eselect mesa set $arch $chip classic &>/dev/null; done; done
+for arch in 32bit 64bit; do for chip in i915 i965 r300 r600 sw; do eselect mesa set $arch $chip classic &>/dev/null; done; done
 
 # Create backups of original xorg.conf.* files and replacing with snail's versions
 [[ -f /etc/X11/xorg.conf && ! -f /etc/X11/xorg.conf.snail-bkp ]] && mv /etc/X11/xorg.conf /etc/X11/xorg.conf.snail-bkp
@@ -19,9 +19,3 @@ BusIDIntel="PCI:`lspci | grep VGA | grep Intel | cut -d" " -f1 | sed 's~\.~\:~g
 BusIDNvidia="PCI:`lspci | grep VGA | grep nVidia | cut -d" " -f1 | sed 's~\.~\:~g ; s~0\([0-9]\)~\1~g'`"
 sed -i "s~BusIDIntel~$BusIDIntel~" /etc/X11/xorg.conf.intel
 sed -i "s~BusIDNvidia~$BusIDNvidia~" /etc/X11/xorg.conf.nvidia
-
-# Allow in sudo for %video group to start/stop second X-server with nVidia card and run snail.dmidecode
-sed -i '/snail/d' /etc/sudoers
-sudoers_lines=`wc -l /etc/sudoers | cut -d" " -f1`
-sed -i "${sudoers_lines}a#snail:\n#snail: Allow %video group to start/stop second X-server with nVidia card\n#snail:\n%video ALL= NOPASSWD: /etc/init.d/snail start\n%video ALL= NOPASSWD: /etc/init.d/snail stop\n%video ALL= NOPASSWD: /usr/local/sbin/snail.dmidecode" /etc/sudoers
-
diff --git a/snail.uninstall b/snail.uninstall
new file mode 100755
index 0000000..b3bcd02
--- /dev/null
+++ b/snail.uninstall
@@ -0,0 +1,34 @@
+#!/bin/sh
+
+# Tell the system to use both xorg-x11 OpenGL and GLX libraries
+eselect opengl set xorg-x11
+
+# Restore xorg.conf.* files from backups
+[ -f /etc/X11/xorg.conf.snail-bkp ] && rm -f /etc/X11/xorg.conf && mv /etc/X11/xorg.conf.snail-bkp /etc/X11/xorg.conf
+[ -f /etc/X11/xorg.conf.intel.snail-bkp ] && rm -f /etc/X11/xorg.conf.intel && mv /etc/X11/xorg.conf.intel.snail-bkp /etc/X11/xorg.conf.intel
+[ -f /etc/X11/xorg.conf.nvidia.snail-bkp ] && rm -f /etc/X11/xorg.conf.nvidia && mv /etc/X11/xorg.conf.nvidia.snail-bkp /etc/X11/xorg.conf.nvidia
+
+# Remove backup files
+for f in "" .intel .nvidia ; do
+	rm -f /etc/X11/xorg.conf${f}.snail-bkp
+done
+
+# Remove all Snail files
+rm -f /etc/X11/xorg.conf.intel.snail
+rm -f /etc/X11/xorg.conf.nvidia
+rm -f /etc/init.d/snail-watcher
+rm -f /etc/init.d/snail-xserver
+rm -f /usr/local/bin/nvrun
+rm -f /usr/local/bin/snail.vglrun
+rm -f /usr/local/lib64/libdlfaker.so
+rm -f /usr/local/lib64/libgefaker.so
+rm -f /usr/local/lib64/librrfaker.so
+rm -f /usr/local/lib64/snail/extensions
+rm -f /usr/local/lib64/snail/modules/drivers
+rm -f /usr/local/lib64/snail/modules/extensions
+rm -f /usr/local/lib64/snail/modules/libfb.so
+rm -f /usr/local/lib64/snail/modules/libwfb.so
+rmdir /usr/local/lib64/snail/modules 2>/dev/null
+rm -f /usr/local/sbin/snail.nv_pwr_off
+rm -f /usr/local/sbin/snail.nv_pwr_on
+rm -f /usr/local/sbin/snail.watcher
diff --git a/usr/local/bin/nvrun b/usr/local/bin/nvrun
index 8ecb30e..3ddd719 100755
--- a/usr/local/bin/nvrun
+++ b/usr/local/bin/nvrun
@@ -1,68 +1,30 @@
-#!/bin/sh
+#!/bin/bash
 
-LOCK_FILE=/tmp/.snail.nvrun.lock
-NVRUN=snail.nvrun
+PATH=/usr/local/sbin:/usr/local/bin:$PATH
 
-(
-        let i=16
-        while [ 0 -lt $i ]; do
-		flock -n 9
-		status=$?
+TIMEOUT=5           # wait timeout for X server start
+let INTEL_IF_FAIL=1 # run on Intel if nVidia fails
 
-		if [[ 0 -ne $status && 5 -eq $i ]]; then
-			echo "Cann't lock $COUNT_FILE. Exiting..."
-			exit -1
+SERVICE=/etc/init.d/snail-xserver
+PROC=nvrun
 
-		elif [ 0 -eq $status ]; then
-			break
-		fi
+LOCK_FILE=/tmp/.snail.lock
+FIFO_FILE=/tmp/.snail.fifo
 
-                sleep 0.01
-                let i--
-	done
 
-	snail.nvstat || snail.nvon
+{
+  echo -n >$FIFO_FILE
+  flock -w $TIMEOUT -s 9
 
-	if [ 0 -ne $? ]; then
-		echo "Cann't switch on nVidia graphics. Exiting..."
-		exit -1
-	fi
+  if [ 0 -eq $? ]; then
+	echo "Running $@ on nVidia"
+	LD_PRELOAD="/usr/lib/opengl/nvidia/lib/libGL.so:/usr/lib/opengl/nvidia/lib/libnvidia-tls.so" snail.vglrun -d :1 "$@"
+	echo "Application $@ was performed on nVidia"
 
-) 9>$LOCK_FILE || exit $?
-
-snail.nvrun "$@"
-
-(
-        let i=16
-        while [ 0 -lt $i ]; do
-		flock -n 9
-		status=$?
-
-		if [[ 0 -ne $status && 5 -eq $i ]]; then
-			echo "Cann't lock $COUNT_FILE. Exiting..."
-			exit -1
-
-		elif [ 0 -eq $status ]; then
-			break
-		fi
-
-                sleep 0.01
-                let i--
-	done
-
-	pgrep $NVRUN &>/dev/null
-
-	if [ 0 -eq $? ]; then
-		echo "Other applications still use nVidia chip. So we aren't switching off it, just exiting..."
-		exit 0
-	else
-		snail.nvoff
-		[ 0 -ne $? ] && echo "Error: Cann't switch off nVidia graphics. Exiting..." && exit -1
-		echo "nVidia chip powered off."
-		exit 0
-	fi
-
-) 9>$LOCK_FILE
-
-exit $?
+  elif [ 0 -ne $INTEL_IF_FAIL ]; then
+	echo "Running $@ on Intel"
+	"$@"
+	echo "Application $@ was performed on Intel"
+  fi
 
+} 9 > $LOCK_FILE
diff --git a/usr/local/bin/snail.nvoff b/usr/local/bin/snail.nvoff
deleted file mode 100755
index d979229..0000000
--- a/usr/local/bin/snail.nvoff
+++ /dev/null
@@ -1,4 +0,0 @@
-#!/bin/sh
-
-sudo /etc/init.d/snail stop
-
diff --git a/usr/local/bin/snail.nvon b/usr/local/bin/snail.nvon
deleted file mode 100755
index c6e3214..0000000
--- a/usr/local/bin/snail.nvon
+++ /dev/null
@@ -1,4 +0,0 @@
-#!/bin/sh
-
-sudo /etc/init.d/snail start
-
diff --git a/usr/local/bin/snail.nvrun b/usr/local/bin/snail.nvrun
deleted file mode 100755
index 3625894..0000000
--- a/usr/local/bin/snail.nvrun
+++ /dev/null
@@ -1,16 +0,0 @@
-#!/bin/sh
-
-snail.nvstat
-
-if [ "$?" == 0 ]; then
-	echo "Running $@ on nVidia Optimus"
-	LD_PRELOAD="/usr/lib/opengl/nvidia/lib/libGL.so:\
-/usr/lib/opengl/nvidia/lib/libnvidia-tls.so" snail.vglrun -d :1 "$@"
-	echo "Application $@ was performed on nVidia Optimus"
-
-else
-	echo "Running $@ on Intel GPU"
-	"$@"
-	echo "Application $@ was performed on Intel GPU"
-fi
-
diff --git a/usr/local/bin/snail.nvstat b/usr/local/bin/snail.nvstat
deleted file mode 100755
index e22ed95..0000000
--- a/usr/local/bin/snail.nvstat
+++ /dev/null
@@ -1,11 +0,0 @@
-#!/bin/sh
-
-[ -f /tmp/.X1-lock ] &&  pgrep -s `cat /tmp/.X1-lock` &>/dev/null
-
-let status=$?
-
-[ 0 -eq $status ] && echo "nVidia graphics is ACTIVE" \
-                  || echo "nVidia graphics is NOT ACTIVE"
-
-exit $status
-
diff --git a/usr/local/sbin/snail.autostop b/usr/local/sbin/snail.autostop
deleted file mode 100755
index daeba88..0000000
--- a/usr/local/sbin/snail.autostop
+++ /dev/null
@@ -1,34 +0,0 @@
-#!/bin/sh
-
-LOCK_FILE=/tmp/.snail.nvrun.lock
-NVRUN=nvrun
-
-while [ 1 ]; do
-	if [ ! `pgrep $NVRUN` ]; then
-
-		(
-		for i in 0 1 2 3 4 5; do
-			flock -n 9
-			status=$?
-	
-			if [[ 0 -ne $status && 5 -eq $i ]]; then
-				echo "Cann't lock $COUNT_FILE. Exiting..."
-				exit -1
-	
-			elif [ 0 -eq $status ]; then
-				break
-			fi
-	
-			sleep 0.01
-		done
-
-		snail.nvoff
-		[ 0 -ne $? ] && echo "Error: Cann't switch off nVidia graphics. Exiting..." && exit -1
-		echo "nVidia chip powered off."
-		exit 0
-		) 9>$LOCK_FILE ; exit $?
-	fi
-
-	sleep 0.1
-done
-
diff --git a/usr/local/sbin/snail.dmidecode b/usr/local/sbin/snail.dmidecode
deleted file mode 100755
index fd8af70..0000000
--- a/usr/local/sbin/snail.dmidecode
+++ /dev/null
@@ -1,4 +0,0 @@
-#!/bin/sh
-
-dmidecode $@ -s system-product-name
-
diff --git a/usr/local/bin/snail.nv_pwr_off b/usr/local/sbin/snail.nv_pwr_off
similarity index 98%
rename from usr/local/bin/snail.nv_pwr_off
rename to usr/local/sbin/snail.nv_pwr_off
index 016aea4..e8bf408 100755
--- a/usr/local/bin/snail.nv_pwr_off
+++ b/usr/local/sbin/snail.nv_pwr_off
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-model=`sudo snail.dmidecode`
+model=`dmidecode $@ -s system-product-name`
 
 let retry=8
 while [ 0 -lt $retry ]; do
diff --git a/usr/local/bin/snail.nv_pwr_on b/usr/local/sbin/snail.nv_pwr_on
similarity index 97%
rename from usr/local/bin/snail.nv_pwr_on
rename to usr/local/sbin/snail.nv_pwr_on
index f35ec3e..2ede6e2 100755
--- a/usr/local/bin/snail.nv_pwr_on
+++ b/usr/local/sbin/snail.nv_pwr_on
@@ -1,6 +1,6 @@
 #!/bin/sh
 
-model=`sudo snail.dmidecode`
+model=`dmidecode $@ -s system-product-name`
 
 let retry=8
 while [ 0 -lt $retry ]; do
diff --git a/usr/local/sbin/snail.uninstall b/usr/local/sbin/snail.uninstall
deleted file mode 100755
index 43bdcbd..0000000
--- a/usr/local/sbin/snail.uninstall
+++ /dev/null
@@ -1,18 +0,0 @@
-#!/bin/sh
-
-# Tell the system to use both xorg-x11 OpenGL and GLX libraries
-eselect opengl set xorg-x11
-
-# Restore xorg.conf.* files from backups
-[ -f /etc/X11/xorg.conf.snail-bkp ] && rm -f /etc/X11/xorg.conf && mv /etc/X11/xorg.conf.snail-bkp /etc/X11/xorg.conf
-[ -f /etc/X11/xorg.conf.intel.snail-bkp ] && rm -f /etc/X11/xorg.conf.intel && mv /etc/X11/xorg.conf.intel.snail-bkp /etc/X11/xorg.conf.intel
-[ -f /etc/X11/xorg.conf.nvidia.snail-bkp ] && rm -f /etc/X11/xorg.conf.nvidia && mv /etc/X11/xorg.conf.nvidia.snail-bkp /etc/X11/xorg.conf.nvidia
-
-# Remove backup files
-for f in "" .intel .nvidia ; do
-	rm -f /etc/X11/xorg.conf${f}.snail-bkp
-done
-
-# Remove records in sudoers
-sed -i '/snail/d' /etc/sudoers
-
diff --git a/usr/local/sbin/snail.watcher b/usr/local/sbin/snail.watcher
new file mode 100755
index 0000000..6420e32
--- /dev/null
+++ b/usr/local/sbin/snail.watcher
@@ -0,0 +1,31 @@
+#!/bin/bash
+
+PATH=/usr/local/sbin:/usr/local/bin:$PATH
+
+SERVICE=/etc/init.d/snail-xserver
+PROC=nvrun
+
+LOCK_FILE=/tmp/.snail.lock
+FIFO_FILE=/tmp/.snail.fifo
+
+$SERVICE stop && snail.nv_pwr_off # stop X service
+
+touch $LOCK_FILE && chown 0:0 $LOCK_FILE # create lock file
+rm -f $FIFO_FILE && mkfifo --mode 640 $FIFO_FILE && chgrp video $FIFO_FILE # create fifo
+
+{
+  echo >$FIFO_FILE | cat <$FIFO_FILE >/dev/null # flush fifo
+  flock -n 9 # make exclusive lock
+
+  while [ 1 ]; do
+    cat <$FIFO_FILE >/dev/null
+    flock -u 9 # unlock to get access for clients
+    flock -n 9
+    if [ 0 -ne $? ]; then # test is $LOCK_FILE locked by any client
+      snail.nv_pwr_on && $SERVICE start # starting X server
+      flock 9
+      echo >$FIFO_FILE | cat <$FIFO_FILE >/dev/null # flush fifo
+      $SERVICE stop && snail.nv_pwr_off # stopping X server
+    fi
+  done
+} 9 > $LOCK_FILE

From 7d36cbda32d3269546d9295f5046f7263874448c Mon Sep 17 00:00:00 2001
From: Kolan Sh <mecareful@gmail.com>
Date: Wed, 21 Mar 2012 00:15:32 +0400
Subject: [PATCH 2/2] fifo/lock fixes

---
 etc/init.d/snail-watcher        | 18 +++++++++++-------
 usr/local/bin/nvrun             |  8 +++++---
 usr/local/sbin/snail.watcher    | 31 -------------------------------
 usr/local/sbin/snail.watcher.sh | 28 ++++++++++++++++++++++++++++
 4 files changed, 44 insertions(+), 41 deletions(-)
 delete mode 100755 usr/local/sbin/snail.watcher
 create mode 100755 usr/local/sbin/snail.watcher.sh

diff --git a/etc/init.d/snail-watcher b/etc/init.d/snail-watcher
index fa96087..1ccdf30 100755
--- a/etc/init.d/snail-watcher
+++ b/etc/init.d/snail-watcher
@@ -1,8 +1,9 @@
 #!/sbin/runscript
 
-DAEMON="/usr/local/sbin/snail.watcher"
+DAEMON="/usr/local/sbin/snail.watcher.sh"
 DAEMON_ARGS=""
 PIDFILE=/var/run/snail.pid
+#PATH=/usr/local/sbin:/usr/local/bin:$PATH
 PATH=$PATH:/usr/local/bin
 
 depend() {
@@ -11,16 +12,19 @@ depend() {
 
 start() {
         ebegin "Starting ${SVCNAME}"
-        start-stop-daemon -m -b --start --exec $DAEMON \
-            --pidfile $PIDFILE \
-            -- $DAEMON_ARGS
+        start-stop-daemon --make-pidfile \
+			  --background \
+                          --start \
+                          --exec $DAEMON \
+                          --pidfile $PIDFILE \
+                          -- $DAEMON_ARGS
         eend $?
 }
 
 stop() {
         ebegin "Stopping ${SVCNAME}"
-        start-stop-daemon --stop --exec $DAEMON \
-            --pidfile $PIDFILE
+        start-stop-daemon --stop \
+                          --exec $DAEMON \
+                          --pidfile $PIDFILE
         eend $?
 }
-
diff --git a/usr/local/bin/nvrun b/usr/local/bin/nvrun
index 3ddd719..d8bf067 100755
--- a/usr/local/bin/nvrun
+++ b/usr/local/bin/nvrun
@@ -2,7 +2,7 @@
 
 PATH=/usr/local/sbin:/usr/local/bin:$PATH
 
-TIMEOUT=5           # wait timeout for X server start
+TIMEOUT=10           # wait timeout for X server start
 let INTEL_IF_FAIL=1 # run on Intel if nVidia fails
 
 SERVICE=/etc/init.d/snail-xserver
@@ -13,7 +13,7 @@ FIFO_FILE=/tmp/.snail.fifo
 
 
 {
-  echo -n >$FIFO_FILE
+  echo -n > $FIFO_FILE &
   flock -w $TIMEOUT -s 9
 
   if [ 0 -eq $? ]; then
@@ -27,4 +27,6 @@ FIFO_FILE=/tmp/.snail.fifo
 	echo "Application $@ was performed on Intel"
   fi
 
-} 9 > $LOCK_FILE
+  flock -u 9
+
+} 9>$LOCK_FILE
diff --git a/usr/local/sbin/snail.watcher b/usr/local/sbin/snail.watcher
deleted file mode 100755
index 6420e32..0000000
--- a/usr/local/sbin/snail.watcher
+++ /dev/null
@@ -1,31 +0,0 @@
-#!/bin/bash
-
-PATH=/usr/local/sbin:/usr/local/bin:$PATH
-
-SERVICE=/etc/init.d/snail-xserver
-PROC=nvrun
-
-LOCK_FILE=/tmp/.snail.lock
-FIFO_FILE=/tmp/.snail.fifo
-
-$SERVICE stop && snail.nv_pwr_off # stop X service
-
-touch $LOCK_FILE && chown 0:0 $LOCK_FILE # create lock file
-rm -f $FIFO_FILE && mkfifo --mode 640 $FIFO_FILE && chgrp video $FIFO_FILE # create fifo
-
-{
-  echo >$FIFO_FILE | cat <$FIFO_FILE >/dev/null # flush fifo
-  flock -n 9 # make exclusive lock
-
-  while [ 1 ]; do
-    cat <$FIFO_FILE >/dev/null
-    flock -u 9 # unlock to get access for clients
-    flock -n 9
-    if [ 0 -ne $? ]; then # test is $LOCK_FILE locked by any client
-      snail.nv_pwr_on && $SERVICE start # starting X server
-      flock 9
-      echo >$FIFO_FILE | cat <$FIFO_FILE >/dev/null # flush fifo
-      $SERVICE stop && snail.nv_pwr_off # stopping X server
-    fi
-  done
-} 9 > $LOCK_FILE
diff --git a/usr/local/sbin/snail.watcher.sh b/usr/local/sbin/snail.watcher.sh
new file mode 100755
index 0000000..16384ad
--- /dev/null
+++ b/usr/local/sbin/snail.watcher.sh
@@ -0,0 +1,28 @@
+#!/bin/bash
+
+PATH=/usr/local/sbin:/usr/local/bin:$PATH
+
+SERVICE=/etc/init.d/snail-xserver
+PROC=nvrun
+
+LOCK_FILE=/tmp/.snail.lock
+FIFO_FILE=/tmp/.snail.fifo
+
+$SERVICE stop && snail.nv_pwr_off # stop X service
+
+touch $LOCK_FILE && chown root:video $LOCK_FILE && chmod 660 $LOCK_FILE # create lock file
+rm -f $FIFO_FILE && mkfifo --mode 660 $FIFO_FILE && chgrp video $FIFO_FILE # create fifo
+
+{
+  echo >$FIFO_FILE | cat $FIFO_FILE >/dev/null # flush fifo
+  flock -n 9 # make exclusive lock
+
+  while [ 1 ]; do
+    read <$FIFO_FILE
+    snail.nv_pwr_on && $SERVICE start # starting X server
+    flock -u 9
+    flock 9
+    echo >$FIFO_FILE | cat $FIFO_FILE >/dev/null # flush fifo
+    $SERVICE stop && snail.nv_pwr_off # stopping X server
+  done
+} 9>$LOCK_FILE