BASH: NetSpark IO Geeklet

netspark

#!/usr/bash
INTF=en0
MAXPOINTS=30

echo $1;
if [ "$1" == "RESET" ]; then
	defaults write netspark in ""
	defaults write netspark out ""
	defaults write netspark lastIn 0
	defaults write netspark lastOut 0
	defaults read netspark
	echo "Reset complete";
	exit
fi

Z0i=`defaults read netspark in`
Z0o=`defaults read netspark out`
lastIn=`defaults read netspark lastIn`
lastOut=`defaults read netspark lastOut`

S=(`/usr/sbin/netstat -ib | awk "/$INTF/"'{print $7" "$10; exit}'`)
normIn=`echo ${S[0]}-$lastIn | bc`;
normOut=`echo ${S[1]}-$lastOut | bc`;

cnt=0
for i in $Z0i ;
do
	let cnt=$cnt+1;
done

if [ "$cnt" -lt "$MAXPOINTS" ]; then
	Z0i=`echo $Z0i $normIn`
	Z0o=`echo $Z0o $normOut`
else
	Z1i=`echo $Z0i | sed "s/[0-9]*\ //"`
	Z1o=`echo $Z0o | sed "s/[0-9]*\ //"`
	Z0i=`echo $Z1i $normIn`
	Z0o=`echo $Z1o $normOut`
fi

defaults write netspark in "$Z0i"
defaults write netspark out "$Z0o"
defaults write netspark lastIn "${S[0]}"
defaults write netspark lastOut "${S[1]}"

echo "In : `printf '%7d' $normIn` `/usr/local/bin/spark $Z0i`"
echo "Out: `printf '%7d' $normOut` `/usr/local/bin/spark $Z0o`"