calc

#!/bin/bash

#A simple script to do floating point maths
#Author: David Dickinson
#Date: 22/06/2010
#Updated: 30/05/2012

#Define expected number of arguements
EXPECTED_ARGS=1

#Check we get sufficient parameters
if [ ! $# -eq $EXPECTED_ARGS ] 
then
	echo "Error: recieved "$#" args when expected exactly "$EXPECTED_ARGS
	echo $0 "usage: "$0" calculation"
	echo "Tip: Consider wrapping your command in quotes!"
	exit 1
fi


#Split options string
NPAR=`echo ${1} | awk -F";" '{print NF}'`
if [ ${NPAR} -eq 1 ]
then
    VAL=${1}
    OPT=""
else
    VAL=`echo ${1} | awk -F";" '{print $2}'`
    OPT=`echo ${1} | awk -F";" '{print $1}'`"; "
fi

#Handle continued lines
VAL=`echo ${VAL} | sed ':a;N;$!ba;s/\\\n//g' | sed 's/\\\ //g'`

#Handle exponential notation
VAL=`echo ${VAL} | sed 's/[eEdD]\([-+0-9]*\)/\*10\^(0\1)/g'`

#ECHO calculation to bc and make sure normal formatting used!
echo "scale=8; ${OPT}${VAL}" | bc | sed 's/\-\./\-0\./g' | sed 's/^\./0./g'

exit 0