create arrays from for loop output - arrays

Question

I'm trying to understand what I'm doing wrong here, but can't seem to determine the cause. I would like to create a set of arrays from an output for a for loop in bash. Below is the code I have so far:
for i in `onedatastore list | grep pure02 | awk '{print $1}'`;
do
arr${i}=($(onedatastore show ${i} | sed 's/[A-Z]://' | cut -f2 -d\:)) ;
echo "Output of arr${i}: ${arr${i}[#]}" ;
done
The output for the condition is as such:
107
108
109
What I want to do is based on these unique IDs is create arrays:
arr107
arr108
arr109
The arrays will have data like such in each:
[oneadmin#opennebula/]$ arr107=($(onedatastore show 107 | sed 's/[A-Z]://' | cut -f2 -d\:))
[oneadmin#opennebula/]$ echo ${arr107[#]}
DATASTORE 107 INFORMATION 107 pure02_vm_datastore_1 oneadmin oneadmin 0 IMAGE vcenter vcenter /var/lib/one//datastores/107 FILE READY DATASTORE CAPACITY 60T 21.9T 38.1T - PERMISSIONS um- u-- --- DATASTORE TEMPLATE CLONE_TARGET="NONE" DISK_TYPE="FILE" DS_MAD="vcenter" LN_TARGET="NONE" RESTRICTED_DIRS="/" SAFE_DIRS="/var/tmp" TM_MAD="vcenter" VCENTER_CLUSTER="CLUSTER01" IMAGES
When I try this in the script section though I get output errors as such:
./test.sh: line 6: syntax error near unexpected token `$(onedatastore show ${i} | sed 's/[A-Z]://' | cut -f2 -d\:)'
I can't seem to figure out the syntax to use on this scenario.
In the end what I want to do is be able to compare different datastores and based on which on has more free space, deploy VMs to it.
Hope someone can help. Thanks

Answer 1

You can use the eval (potentially unsafe) and declare (safer) commands:
for i in $(onedatastore list | grep pure02 | awk '{print $1}');
do
declare "arr$i=($(onedatastore show ${i} | sed 's/[A-Z]://' | cut -f2 -d\:))"
eval echo 'Output of arr$i: ${arr'"$i"'[#]}'
done

Answer 2

readarray or mapfile, added in bash 4.0, will read directly into an array:
while IFS= read -r i <&3; do
readarray -t "arr$i" < <(onedatastore show "$i" | sed 's/[A-Z]://' | cut -f2 -d:)
done 3< <(onedatastore list | awk '/pure02/ {print $1}')
Better, back through bash 3.x, one can use read -a to read to an array:
shopt -s pipefail # cause pipelines to fail if any element does
while IFS= read -r i <&3; do
IFS=$'\n' read -r -d '' -a "arr$i" \
< <(onedatastore show "$i" | sed 's/[A-Z]://' | cut -f2 -d: && printf '\0')
done 3< <(onedatastore list | awk '/pure02/ {print $1}')
Alternately, one can use namevars to create an alias for an array with an arbitrarily-named array in bash 4.3:
while IFS= read -r i <&3; do
declare -a "arr$i"
declare -n arr="arr$i"
# this is buggy: expands globs, string-splits on all characters in IFS, etc
# ...but, well, it's what the OP is asking for...
arr=( $(onedatastore show "$i" | sed 's/[A-Z]://' | cut -f2 -d:) )
done 3< <(onedatastore list | awk '/pure02/ {print $1}')