Shell Programming and Scripting

i=0
for true in DMGLIST[@]
	do
	let DMGSIZES2[i]="${DMGSIZES[i]}"*2
	let i++
done
unset i

echo ${DMGSIZES2[@]}

DMGLIST=(1 2 3 4)
for (( i = 0 ; i < "${#DMGLIST[@]}"; i++ )) 
do
    DMGLIST2[$i]=$((${DMGLIST[$i]}*2))
    echo "${DMGLIST2[$i]}";
done

[root@~]# bash array.sh 
2 4 6
[root@~]# cat array.sh 
#!/bin/bash
b=(1 2 3)
a=0
for i in ${b[@]}
do
    narray[${a}]=$((${b[$a]}*2))
    ((a++))
done
echo ${narray[@]}
 
Test environment : centos 5.5 64bit
GNU bash, version 3.2.25

#!/bin/bash
b=(2 4 6)
a=0
for i in ${b[@]}
do
    narray[a++]=$((i*2))
done
echo ${narray[@]}