Speed improvements to several of the status programs.

* cpu_freq:
   from: 0m4.911s, 0m0.060s, 0m0.270s
   to__: 0m0.147s, 0m0.130s, 0m0.010s
 * wifi_quality:
   from: 0m21.201s, 0m0.260s, 0m0.540s
   to__: 0m6.418s,  0m0.190s, 0m0.140s
 * uptime:
   from: 0m9.262s, 0m0.150s, 0m0.380s
   to__: 0m0.103s, 0m0.050s, 0m0.040s
 * load_avg:
   from: 0m4.964s, 0m0.060s, 0m0.240s
   to__: 0m0.083s, 0m0.040s, 0m0.040s
 * disk_io, network:
   speed improvements were harder to track to due caching.  Several forks
   were removed in each.
   These are less tested though at the moment.
 * Add 'fpdiv' function to do floating-point-like math in shell.
 * Add 'rtrim' function like php 'rtrim'

Time output above is ordered as 'real, user, sys' for 1000 runs on my T400
laptop, which was otherwise generally idle

The 'loopit' command below is used to test speed improvements like this:
   time loopit 1000 . ./usr/lib/byobu/cpu_freq

## begin loopit
#!/bin/sh
cr() { "$@"; echo; }
times=$1
shift
i=0;
. ./usr/lib/byobu/.shutil
while [ $i -lt $times ]; do
   "$@"
   i=$(($i+1))
done
## end loopit

usr/lib/byobu/.shutil

@@ -36,3 +36,32 @@ find_script() {
 		_RET="/dev/null"
 	fi
 }
+
+# divide 2 integers and return a floating point number
+# third argument indicates how many digits after the decimal
+fpdiv() {
+	local a=$1 b=$2 pres=${3:-3}
+	local i=0 mp="10" whole="" part=""
+	while i=$(($i+1)) && [ $i -le $pres ]; do
+		mp="${mp}0"
+	done
+	whole=$(($a/$b))
+	part=$((((($a%$b)*${mp})/$b)))
+	if [ $part -eq 0 ]; then
+		part=$(($mp/10)); part=${part#1};
+	elif [ $((${part}%(${mp}/10))) -ge 5 ]; then
+		part=$(($part+5))
+	fi
+	_RET="${whole}.${part%?}"
+}
+
+# rtrim(string,chars)
+rtrim() {
+	local tab=' ' cr="
+"
+	local cur="${1}" set="[${2:- ${tab}${cr}}]" n=""
+	while n=${cur%${set}} && [ "$n" != "$cur" ]; do cur=${n}; done
+	_RET=${cur}
+}
+
+# vi: syntax=sh ts=4 noexpandtab

usr/lib/byobu/cpu_freq

@@ -26,7 +26,9 @@ if [ "$1" = "--detail" ]; then
 fi
 
 if [ -r "/sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq" ]; then
-	freq=$(awk '{ printf "%.1f", $1 / 1000000 }' /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq)
+	read hz < /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
+	fpdiv $hz "1000000" 1 # 1Ghz
+   freq="$_RET"
 else
 	if egrep -q -s -i -m 1 "^cpu MHz|^clock" /proc/cpuinfo; then
 		freq=$(egrep -i -m 1 "^cpu MHz|^clock" /proc/cpuinfo | awk -F"[:.]" '{ printf "%.1f", $2 / 1000 }')

usr/lib/byobu/disk_io

@@ -20,20 +20,26 @@
 PKG="byobu"
 DATA="$HOME/.$PKG"
 color 2>/dev/null || color() { true; }
+getdisk() {
+	local t=""
+	if [ -L "${1}" ]; then
+		command -v greadlink >/dev/null && READLINK=greadlink || READLINK=readlink
+		t=$($READLINK -f "$1")
+	else
+		t="$1"
+	fi
+	t="${t##*/}";
+	rtrim "$t" "0-9"
+}
+
 [ "$UTF8" = "1" ] && ICON_RD="◀" || ICON_RD="<"
 [ "$UTF8" = "1" ] && ICON_WR="▶" || ICON_WR=">"
 
 # Default to disk providing /, but let users override with MONITORED_DISK
 [ -z "$MONITORED_DISK" ] && MP="/" ||  MP="$MONITORED_DISK"
-case $MP in
-	/dev/*) disk="$MP" ;;
-	*) disk=$(grep -m 1 " $MP " /etc/mtab | sed -e "s: .*$::") ;;
-esac
-which greadlink 2>/dev/null && READLINK="greadlink" || READLINK="readlink"
-disk=$($READLINK -f "$disk" | sed -e "s: .*$::" -e "s:^.*/::" -e "s:\([hsv]d[a-z]\)[0-9]*$:\1:")
 
 if [ "$1" = "--detail" ]; then
-	if which iostat >/dev/null; then
+	if command -v >/dev/null; then
 		iostat -d -m -h
 	else
 		echo "Please install iostat if you want detailed information on your disk throughput"
@@ -41,6 +47,13 @@ if [ "$1" = "--detail" ]; then
 	exit 0
 fi
 
+case "$MP" in
+	/dev/*) part="${MP}";;
+	*) part=$(awk '$2 == mp { print $1 ; exit(0); }' "mp=$MP" /etc/mtab);;
+esac
+getdisk "$part"
+disk=${_RET}
+
 [ -d "/var/run/screen/S-$USER" ] && DIR="/var/run/screen/S-$USER" || DIR="$DATA"
 t2=`date +%s`
 for i in "read" "write"; do
@@ -50,20 +63,21 @@ for i in "read" "write"; do
 	if [ $t2 -le $t1 ]; then
 		rate=0
 	else
-		x1=`cat "$cache"` 2>/dev/null || tx1=0
+		[ -r "$cache" ] && read x1 < "$cache" || x1=0
+		read a1 a2 a3 a4 a5 a6 a7 a8 a9 a10 other < "/sys/block/$disk/stat"
 		if [ "$i" = "read" ]; then
 			symbol="$ICON_RD"
-			x2=`awk '{print $3}' /sys/block/$disk/stat`
+			x2="$a3"
 		else
 			symbol="$ICON_WR"
-			x2=`awk '{print $7}' /sys/block/$disk/stat`
+			x2="$a7"
 		fi
 		echo "$x2" > "$cache"
-		rate=`echo "$t1" "$t2" "$x1" "$x2" | awk '{printf "%.0f", ($4 - $3) / ($2 - $1) * 512 / 1024 }'`
+		rate=$((($x2-$x1) / ($t2 - $t1) * 512 / 1024))
 		if [ "$rate" -lt 0 ]; then
 			rate=0
 		elif [ "$rate" -gt 1024 ]; then
-			rate=`echo "$rate" | awk '{printf "%.1f", $1/1024}'`
+			fpdiv "$rate" 1024 1
 			unit="MB/s"
 		fi
 	fi

usr/lib/byobu/load_average

@@ -24,5 +24,5 @@ if [ "$1" = "--detail" ]; then
 	cat /proc/loadavg
 	exit 0
 fi
-
-color Y k; printf "%s" "$(awk '{print $1}' /proc/loadavg)"; color --
+read one five fifteen other < /proc/loadavg
+color Y k; printf "$one"; color --

usr/lib/byobu/network

@@ -27,7 +27,8 @@ color 2>/dev/null || color() { true; }
 if [ -n "$MONITORED_NETWORK" ]; then
 	interface="$MONITORED_NETWORK"
 else
-	interface=`tail -n1 /proc/net/route  | awk '{print $1}'`
+	# get the last interface listed in /proc/net/route
+	while read cn other; do interface=$cn; done < /proc/net/route
 fi
 
 if [ "$1" = "--detail" ]; then
@@ -48,24 +49,27 @@ for i in up down; do
 	if [ $t2 -le $t1 ]; then
 		rate=0
 	else
-		x1=`cat "$cache"` 2>/dev/null || tx1=0
-		if [ "$i" = "up" ]; then
-			x2=`grep -m1 "\b$interface:" /proc/net/dev | sed "s/^.*://" | awk '{print $9}'`
-		else
-			x2=`grep -m1 "\b$interface:" /proc/net/dev | sed "s/^.*://" | awk '{print $1}'`
-		fi
+		[ -r "$cache" ] && read x1 < "$cache" || tx1=0
+		while read iface rbytes rpackets rerrs rdrop rfifo rframe rcompressed rmulticast tbytes tpackets terrs tdrop tfifo tcolls tcarrier tcompressed; do
+			if [ "$iface" = "${interface}:" ]; then
+				[ "$i" = "up" ] && x2=${tbytes} || x2=${rbytes}
+				break;
+			fi
+		done < /proc/net/dev
 		echo "$x2" > "$cache"
-		rate=`echo "$t1" "$t2" "$x1" "$x2" | awk '{printf "%.0f", ($4 - $3) / ($2 - $1) / 1024 }'`
+		rate=$((($x2 - $x1) / ($t2 - $t1) / 1024))
 		if [ "$rate" -lt 0 ]; then
 			rate=0
 		fi
 		case "$NETWORK_UNITS" in
 			bytes)
 				if [ "$rate" -gt 1048576 ]; then
-					rate=`echo "$rate" | awk '{printf "%.1f", $1/1048576}'`
+					fpdiv "$rate" 1048576 1
+					rate=${_RET}
 					unit="GB/s"
 				elif [ "$rate" -gt 1024 ]; then
-					rate=`echo "$rate" | awk '{printf "%.1f", $1/1024}'`
+					fpdiv "$rate" 1024 1
+					rate=${_RET}
 					unit="MB/s"
 				else
 					unit="kB/s"
@@ -73,13 +77,15 @@ for i in up down; do
 			;;
 			*)
 				# Default to bps
-				rate=`echo "$rate" | awk '{printf "%.0f", $1*8}'`
+				rate=$(($rate*8))
 				# Why 1000 and not 1024?  http://en.wikipedia.org/wiki/Data_rate_units
 				if [ "$rate" -gt 1000000 ]; then
-					rate=`echo "$rate" | awk '{printf "%.1f", $1/1000000}'`
+					fpdiv "$rate" 1000000 1
+					rate=${_RET}
 					unit="Gbps"
 				elif [ "$rate" -gt 1000 ]; then
-					rate=`echo "$rate" | awk '{printf "%.1f", $1/1000}'`
+					fpdiv "$rate" 1000 1
+					rate=${_RET}
 					unit="Mbps"
 				fi
 			;;

usr/lib/byobu/uptime

@@ -28,15 +28,17 @@ if [ "$1" = "--detail" ]; then
 	exit 0
 fi
 
-u=$(sed "s/\..*$//" /proc/uptime)
+read u idle < /proc/uptime
+u=${u%.*}
 color w b
 if [ "$u" -gt 86400 ]; then
-	echo "$u" | awk '{printf "%dd%dh", $1 / 86400, ($1 % 86400)/3600 }'
+	str="$(($u / 86400))d%$((($u % 86400) / 3600))h"
 elif [ "$u" -gt 3600 ]; then
-	echo "$u" | awk '{printf "%dh%dm", $1 / 3600, ($1 % 3600 )/60}'
+	str="$(($u / 3600))h$((($u % 3600) / 60))m"
 elif [ "$u" -gt 60 ]; then
-	echo "$u" | awk '{printf "%dm", $1 / 60 }'
+	str="$(($u / 60))m"
 else
-	printf "%ds" "$u"
+	str="${u}s"
 fi
+printf "%s" "${str}"
 color --

usr/lib/byobu/wifi_quality

@@ -26,14 +26,22 @@ if [ "$1" = "--detail" ]; then
 	exit 0
 fi
 
-iwconfig=`/sbin/iwconfig $MONITORED_NETWORK 2>/dev/null`
-bitrate=`echo "$iwconfig" | grep "Bit Rate." | sed -e "s/^.*Bit Rate.//" -e "s/ .*$//g"`
+# iwconfig is expected to output lines like:
+#    Bit Rate=54 Mb/s   Tx-Power=15 dBm
+#    Link Quality=60/70  Signal level=-50 dBm
+# the awk below tokenizes the output and prints shell evalable results
+out=`iwconfig $MONITORED_NETWORK 2>/dev/null |
+	awk '$0 ~ /[ ]*Link Quality./ {
+   sub(/.*=/,"",$2); split($2,a,"/");
+   printf "quality=%.0f\n", 100*a[1]/a[2] };
+   $0 ~ /[ ]*Bit Rate/ { sub(/.*=/,"",$2); printf("bitrate=%s\n", $2); }
+   '`
+eval "$out"
+
 [ -z "$bitrate" ] && bitrate="0"
-quality=`echo "$iwconfig" | grep "Link Quality." | sed -e "s/^.*Link Quality.//" -e "s/ .*$//g"`
+
 if [ -z "$quality" ] || [ "$quality" = "0" ]; then
 	quality="0"
-else
-	quality=`echo "$quality" | awk -F/ '{printf "%.0f", 100*$1/$2}'`
 fi
 [ "$quality" = "0" ] && exit 0