[Bash] sum numbers in an array

#!/bin/bash # sum all/part the numbers in an array using bc # usage: #           mysum number-array [index0 index1] #           Note: the index starts from 1 # e.g., #      myA=(34 23 32.5 33.2 25) #      mysum "${myA[*]}" ==> 147.7 #      mysum "${myA[*]}" 1 2 ==> 57 #      mysum "${myA[*]}" 2 4 ==> 88.7 #      mysum "12 23 12" ==> 47 # # http://scriptdemo.blogspot.com isDebug=0 if [ $# -eq 0 ]; then    sed -n '3,8p' `which mysum`    exit else   myA=($1)   [ ${isDebug} -eq 1 ] && echo ${myA[*]}   [ ${isDebug} -eq 1 ] && echo "narg: $#"   if [ $# -eq 1 ]; then      if [ ${isDebug} -eq 1 ]; then         echo "sum: `echo ${myA[*]} | sed 's/\ /+/g' | bc -l`"      else         echo "`echo ${myA[*]} | sed 's/\ /+/g' | bc -l`"      fi   elif [ $# -eq 2 ]; then      ind0=`expr $2 - 1`      nC=`expr ${#myA[*]} - ${ind0}`      if [ ${isDebug} -eq 1 ]; then         echo "sum: `echo ${myA[*]:${ind0}:${nC}} | sed 's/\ /+/g' | bc -l`"      else         echo "`echo ${myA[*]:${ind0}:${nC}} | sed 's/\ /+/g' | bc -l`"      fi   elif [ $# -eq 3 ]; then      ind0=`expr $2 - 1`      nC=`expr $3 - ${ind0}`      if [ ${isDebug} -eq 1 ]; then         echo "sum: `echo ${myA[*]:${ind0}:${nC}} | sed 's/\ /+/g' | bc -l`"      else         echo "`echo ${myA[*]:${ind0}:${nC}} | sed 's/\ /+/g' | bc -l`"      fi   fi