Bash 4 Generate Associative Array - bash

Question

I'm trying to create a nice neat table from output. Here's the code that working off of now:
vmnumber=0
declare -A vm_array=()
for vm in $vms; do
declare vm_array[$vmnumber][cpu]="10"
echo "Test ${vm_array[$vmnumber][cpu]}"
declare vm_array[$vmnumber][memory]="20"
declare vm_array[$vmnumber][diskspace]="20"
vmnumber=$(($vmnumber + 1))
done
# Table output
for((i=0;i<$vmnumber;i++)); do
printf "%10s %10s %10s" vm_array[$i][cpu] vm_array[$i][memory] vm_array[$i][diskspace]"
done
Echo is not working and only the variable names come out in printf.
How can I generate an associative array of out of these values?

Answer 1

Associative arrays support non-numeric keys. They are not multidimensional, and cannot have other arrays as your values. For your use case, use a separate non-associative array per VM, as follows:
# Why this is this associative at all, if your keys are numeric?
vmnumber=0
vm_cpu=() vm_memory=() vm_diskspace=( )
for vm in $vms; do ## aside: don't use for this way
vm_cpu[$vmnumber]="10"
vm_memory[$vmnumber]="20"
vm_diskspace[$vmnumber]="20"
(( ++vmnumber ))
done
# test output
declare -p vm_cpu vm_memory vm_diskspace
# Table output
for i in "${!vm_cpu[#]}"; do # iterate over keys
printf '%10s %10s %10s\n' "${vm_cpu[$i]}" "${vm_memory[$i]}" "${vm_diskspace[$i]}"
done
If you really want a single associative array, that would look like the following:
vmnumber=0
declare -A vm_data=( )
for vm in $vms; do ## aside: don't use for this way
vm_data[cpu_$vmnumber]="10"
vm_data[memory_$vmnumber]="20"
vm_data[diskspace_$vmnumber]="20"
(( ++vmnumber ))
done
# test output
declare -p vm_data
# Table output
for ((i=0; i<vmnumber; i++)); do
printf '%10s %10s %10s\n' "${vm_data[cpu_$i]}" "${vm_data[memory_$i]}" "${vm_data[diskspace_$i]}"
done