From 59a0831fa6cc31cda02ae474d38b10a4d7f1d216 Mon Sep 17 00:00:00 2001
From: Jean Delvare <khali@linux-fr.org>
Date: Tue, 12 Jun 2007 11:36:15 +0000
Subject: [PATCH] More cleanups to fancontrol: * No longer depend on grep. We
 already depend on egrep so let's use it everywhere. * Don't depend on awk to
 compute the target PWM value. Bash has an arithmetic expression evaluation
 engine which does the job just fine. * Use read instead of cat to read the
 sensor values. read is built-in, so it's cheaper. * When sysfs is used (2.6
 kernel), do not postproces the sensor value reads with cut, as it is not
 needed. * Update the dependency list.

git-svn-id: http://lm-sensors.org/svn/lm-sensors/branches/lm-sensors-3.0.0@4441 7894878c-1315-0410-8ee3-d5d059ff63e0
---
 CHANGES             |  2 ++
 prog/pwm/fancontrol | 34 ++++++++++++++++++----------------
 2 files changed, 20 insertions(+), 16 deletions(-)

diff --git a/CHANGES b/CHANGES
index 35f2b803..3f3f84b9 100644
--- a/CHANGES
+++ b/CHANGES
@@ -20,6 +20,8 @@ SVN HEAD
                    Fix Super-I/O exit sequence for Winbond/Fintek chips
   Program mkpatch: Delete
   Program fancontrol: Use let for arithmetic evaluation
+                      No longer need awk and grep
+                      Limit calls to external programs (Linux 2.6 only)
   Program pwmconfig: Use smaller steps for low PWM values
   Program rrd: Support only hwmon class devices
                Look for rrd in /usr/bin by default
diff --git a/prog/pwm/fancontrol b/prog/pwm/fancontrol
index d1007b1c..d70016fb 100755
--- a/prog/pwm/fancontrol
+++ b/prog/pwm/fancontrol
@@ -2,12 +2,12 @@
 #
 # Simple script implementing a temperature dependent fan speed control
 #
-# Version 0.64
+# Version 0.65
 #
 # Usage: fancontrol [CONFIGFILE]
 #
 # Dependencies:
-#   bash, awk, egrep, sed, lm_sensors :)
+#   bash, egrep, sed, cut, sleep, lm_sensors :)
 #
 # Please send any questions, comments or success stories to
 # marius.reiner@hdev.de
@@ -104,7 +104,7 @@ DIR=/proc/sys/dev/sensors
 if [ ! -d $DIR ]
 then
 	# For Linux 2.6, detect if config file uses the hwmon class or not yet
-	if echo "$AFCPWM[0]" | grep '^hwmon[0-9]'
+	if echo "${AFCPWM[0]}" | egrep -q '^hwmon[0-9]'
 	then
 		SDIR=/sys/class/hwmon
 	else
@@ -196,11 +196,6 @@ function restorefans()
 
 trap restorefans SIGHUP SIGINT SIGQUIT SIGTERM SIGKILL
 
-# function doing all the math
-function calc () {
-	awk "BEGIN { print $@ }"
-}
-
 # main function
 function UpdateFanSpeeds {
 	let fcvcount=0
@@ -215,36 +210,43 @@ function UpdateFanSpeeds {
 		minsa=${AFCMINSTART[$fcvcount]}
 		minso=${AFCMINSTOP[$fcvcount]}
 		
-		tval=`cat ${tsens}`
+		read tval < ${tsens}
 		if [ $? -ne 0 ]
 		then
 			echo "Error reading temperature from $DIR/$tsens"
 			restorefans
 		fi
-		tval=`echo ${tval} |cut -d' ' -f3 |cut -d'.' -f1`
 		if [ "$SYSFS" = "1" ]
 		then
-			let tval="$tval / 1000"
+			let tval="($tval+500)/1000"
+		else
+			tval=`echo ${tval} | cut -d' ' -f3 | cut -d'.' -f1`
 		fi
 
-		pwmpval=`cat ${pwmo}`
+		read pwmpval < ${pwmo}
 		if [ $? -ne 0 ]
 		then
 			echo "Error reading PWM value from $DIR/$pwmo"
 			restorefans
 		fi
-		pwmpval=`echo ${pwmpval} | cut -d' ' -f1`
+		if [ "$SYSFS" != "1" ]
+		then
+			pwmpval=`echo ${pwmpval} | cut -d' ' -f1`
+		fi
 		
 		# If fanspeed-sensor output shall be used, do it
 		if [[ -n ${fan} ]]
 		then
-			fanval=`cat ${fan}`
+			read fanval < ${fan}
 			if [ $? -ne 0 ]
 			then
 				echo "Error reading Fan value from $DIR/$fan"
 				restorefans
 			fi
-			fanval=`echo ${fanval} | cut -d' ' -f2`
+			if [ "$SYSFS" != "1" ]
+			then
+				fanval=`echo ${fanval} | cut -d' ' -f2`
+			fi
 		else
 			fanval=1  # set it to a non zero value, so the rest of the script still works
 		fi
@@ -270,7 +272,7 @@ function UpdateFanSpeeds {
 		  then pwmval=255 # at specified maxtemp switch to 100%
 		else 
 		  # calculate the new value from temperature and settings
-		  pwmval=`calc "(((${tval}-${mint})/(${maxt}-${mint}))^2*(255-${minso})+${minso})" |cut -d'.' -f1`
+		  let pwmval="((${tval}-${mint})**2)*(255-${minso})/((${maxt}-${mint})**2)+${minso}"
 		  if [ $pwmpval -eq 0 -o $fanval -eq 0 ]
 		  then # if fan was stopped start it using a safe value
 		  	echo $minsa > $pwmo