diff --git a/bin/brightness b/bin/brightness
index 17c562c..aa7596a 100755
--- a/bin/brightness
+++ b/bin/brightness
@@ -1,5 +1,11 @@
 #!/bin/bash
+source $HOME/.config/sway/bin/helpers
 DEVICE=sysfs/backlight/intel_backlight
+APP=light
+
+## main
+_log BRIGHTNESS INFO args: $*
+_check_app $APP
 
 case $1 in
   d*)
@@ -9,6 +15,7 @@ case $1 in
     light -s $DEVICE -A 10
     ;;
   *)
-    echo "ERROR: invalid command: \"$1\""
+    echo "invalid argument: \"$1\""
+    echo "arguments: [decrease|increase]"
     ;;
 esac
diff --git a/bin/helpers b/bin/helpers
new file mode 100644
index 0000000..7c5c424
--- /dev/null
+++ b/bin/helpers
@@ -0,0 +1,38 @@
+#!/bin/bash
+LOGFILE=$HOME/log/sway.log
+
+## helpers
+function _log() {
+  mkdir -p $(dirname $LOGFILE)
+  echo $(date) $* | tee -a $LOGFILE
+}
+
+function _check_app() {
+  which $1 &> /dev/null
+  if [ $? -ne 0 ]; then
+    _log _check_app: ERROR missing app \"$1\"
+    exit 1
+  fi
+}
+
+function _check_inhibit() {
+  if [ -e $1 ]; then
+    _log _check_inhibit: INFO found inhibit file $1
+    exit 1
+  fi
+}
+
+function _set_inhibit() {
+  file=$1
+  action=$2
+  case "$action" in
+    0|off)
+      rm -f $file
+      _log _set_inhibit: INFO inhibit disabled
+      ;;
+    *)
+      touch $file
+      _log _set_inhibit: INFO inhibit enabled
+      ;;
+  esac
+}
diff --git a/bin/lock b/bin/lock
index 85a810e..243a1ac 100755
--- a/bin/lock
+++ b/bin/lock
@@ -1,50 +1,18 @@
 #!/bin/bash
+source $HOME/.config/sway/bin/helpers
 IMAGE=$HOME/.lockscreen.jpg
 SCROT_APP=grim
 SCROT_ARGS=" -t jpeg"
 LOCK_APP=swaylock
 LOCK_ARGS=" -f -c 000000 -i $IMAGE"
-INHIBIT_FILE=$HOME/.inhibit
-
-
-function _check_app() {
-  which $1 &> /dev/null
-  if [ $? -ne 0 ]; then
-    echo "ERROR: missing app \"$1\""
-    exit 1
-  fi
-}
-
-function _check_inhibit() {
-  if [ -e $INHIBIT_FILE ]; then
-    echo "ERROR: found inhibit file $INHIBIT_FILE"
-    exit 1
-  fi
-}
-
-function _inhibit() {
-  case "$1" in
-    0|off)
-      rm -f $INHIBIT_FILE
-      echo "inhibit disabled"
-      ;;
-    1|on)
-      touch $INHIBIT_FILE
-      echo "inhibit enabled"
-      ;;
-    *)
-      echo "ERROR: unknown argument: $1"
-      ;;
-  esac
-}
+INHIBIT_FILE=$HOME/.inhibit_lock
 
 function _clean() {
   rm -vf $IMAGE
 }
 
 function _lock() {
-  _check_inhibit
-  _check_app $LOCK_APP
+  _check_inhibit $INHIBIT_FILE
   $LOCK_APP $LOCK_ARGS
 }
 
@@ -57,22 +25,18 @@ function _on() {
 }
 
 function _screenshot() {
-  _check_app $SCROT_APP
   $SCROT_APP $SCROT_ARGS $IMAGE
   convert -blur 4x4 $IMAGE $IMAGE
 }
 
-function _suspend() {
-  _check_inhibit
-  systemctl suspend-then-hibernate
-}
-
-mkdir -p $HOME/log
-echo "lock: $(date) args: $*" >> $HOME/log/sway.log
+## main
+_log LOCK INFO args: $*
+_check_app $LOCK_APP
+_check_app $SCROT_APP
 
 case "$1" in
   inhibit)
-    _inhibit $2
+    _set_inhibit $INHIBIT_FILE $2
     ;;
   lock)
     _on
@@ -96,12 +60,9 @@ case "$1" in
     _on
     _screenshot
     ;;
-  suspend)
-    _suspend
-    ;;
   *)
-    echo "invalid argument \"$1\"."
-    echo "arguments: [lock|lockonly|off|on|screenshot]"
+    echo "invalid argument \"$1\""
+    echo "arguments: [inhibit [on|off]|lock|lockonly|off|on|screenshot]"
 esac
 
 
diff --git a/bin/suspend b/bin/suspend
index 823e9b3..2372b00 100755
--- a/bin/suspend
+++ b/bin/suspend
@@ -1,13 +1,16 @@
 #!/bin/bash
+source $HOME/.config/sway/bin/helpers
 BAT_PATH=/sys/class/power_supply
 BAT=BAT0
 MODE=suspend-then-hibernate
+INHIBIT_FILE=$HOME/.inhibit_suspend
 
+## helpers
 # 0: charging
 # 1: discharging/unknown
 function _state() {
   f=$BAT_PATH/$BAT/status
-  s=1 
+  s=1
   if [ -e $f ]; then
     s=$(grep -c Discharging $f)
   fi
@@ -15,20 +18,23 @@ function _state() {
 }
 
 function _suspend() {
+  _check_inhibit $INHIBIT_FILE
   state=$(_state)
   force=${1:-0}
-  echo "INFO: state: $state, force: $force"
   if [ $state -eq 1 -o $force -eq 1 ]; then
     systemctl $MODE
   else
-    echo "ERROR: state: $state, force: $force"
+    _log SUSPEND INFO aborting. state: $state, force: $force
   fi
 }
 
-mkdir -p $HOME/log
-echo "suspend: $(date) args: $*" >> $HOME/log/sway.log
+## main
+_log SUSPEND INFO args: $*
 
 case $1 in
+  inhibit)
+    _set_inhibit $INHIBIT_FILE $2
+    ;;
   suspend)
     _suspend 0
     ;;
@@ -36,7 +42,7 @@ case $1 in
     _suspend 1
     ;;
   *)
-    echo "ERROR: invalid command: \"$1\""
-    echo "possible options: [suspend|force]"
+    echo "invalid argument: \"$1\""
+    echo "arguments: [inhibit [on|off]|suspend|force]"
     ;;
 esac
diff --git a/bin/volume b/bin/volume
index 0c3f0c7..7d7a0a0 100755
--- a/bin/volume
+++ b/bin/volume
@@ -1,13 +1,9 @@
 #!/bin/bash
-sink=$(pacmd list-sinks | grep "* index" | grep -oE '[0-9]*')
-cmd=""
-app="pavucontrol"
-
-if [ -z "$sink" ]; then
-  echo "ERROR: invalid sink: \"$sink\""
-  exit 1
-fi
+source $HOME/.config/sway/bin/helpers
+SINK=$(pacmd list-sinks | grep "* index" | grep -oE '[0-9]*')
+APP="pavucontrol"
 
+##  helpers
 function _toggle() {
   a=$1
   if [ $(pgrep $a) ]; then
@@ -17,20 +13,28 @@ function _toggle() {
   fi
 }
 
+## main
+if [ -z "$SINK" ]; then
+  _log VOLUME ERROR args: $*
+  exit 1
+fi
+
 case $1 in
   d*)
-    pactl set-sink-volume $sink -5%
+    pactl set-sink-volume $SINK -5%
     ;;
   i*)
-    pactl set-sink-volume $sink +5%
+    pactl set-sink-volume $SINK +5%
     ;;
   m*)
-    pactl set-sink-mute $sink toggle
+    pactl set-sink-mute $SINK toggle
     ;;
   gui)
-    _toggle $app
+    _check_app $APP
+    _toggle $APP
     ;;
   *)
-    echo "ERROR: invalid command: \"$1\""
+    echo "invalid command: \"$1\""
+    echo "arguments: [decrease|increase|mute|gui]"
     ;;
 esac