I am writing a loop in bash where I want to include one variable in another variable:
printf "Number of volumes to add: "
read -r num_volumes
for volume_number in "$num_volumes"
do
vol_id_{$volume_number}="create_volume"
done
Is this the correct syntax to use?
First, when ever you're tempted to use variables like foo_1, foo_2, etc., just don't. Use an array instead:
foo=()
foo[0]=123; foo[1]=456;
printf "%s\n" "${foo[@]}"
Or, if you need non-numeric keys, an associative array:
declare -A bar=()
bar[abc]=123; bar[def]=456;
for key in "${!bar[@]}"; do echo "$key: ${bar[$key]}"; done
As for your code, for volume_number in "$num_volumes" will run the loop body once, with volume_number set to the contents of num_volumes. The quotes prevent any splitting of num_volumes so there's only one word for for to loop over. Given that your prompt and variable name refer to a number of something, you probably don't even want to split, but to loop over a list of numbers:
read num
vars=()
for (( i=0; i < num; i++ )); do
vars[i]="some value for $i"
done
