I am refactoring a script that displays a text menu similar to this:
Select a mounted BTRFS device on your local machine to backup to.
1) 123456789abc-def012345-6789abcdef012 (/)
2) 123456789abc-def012345-6789abcdef012 (/home)
...
26) 3e3456789abc-def012345-6789abcdef369 (/mnt/backup2)
27) 223456789abc-def012345-6789abcdef246 (/mnt/backup3)
Note that the menu displays two items of information: the UUID and the target path. Replicating that with the select command is one of the things I do not know how to do.
In this menu, the user enters a number (e.g. 26) and the script performs a BTRFS send|receive to that device & path. I want the script menu to continue working the same way i.e., to display the UUID plus path and take a simple 1 or 2 digit or char input.
However, I want to refactor the code. I did not write the original code. It uses two arrays to display the menu and to handle the selection.
I want to use an associative array. This is purely an exercise for me to gain experience with associative arrays. The script is working as is.
I would like to use the following code which I wrote as a basis for the menu:
declare -A UUID_TARGETS
for target in $TARGETS; do
if ! [[ "$target" =~ ^/mnt|^/backup ]] ; then
echo "skipped $target"
else
UUID_TARGETS["$target"]=$(findmnt -n -t btrfs -o UUID -M "$target")
fi
done
for target in "${!UUID_TARGETS[@]}"; do
#testing
echo UUID [${UUID_TARGETS["$target"]}] has mountpoint [$target]
done
The bash select command doesn't seem to make the menu I want because I need two items of information displayed in the menu: the UUID and the target path. The naive use of select like this isn't quite sufficient:
PS3="Please enter your choice (q to quit): "
select target in "${!UUID_TARGETS[@]}" "quit";
do
case "$target" in
"quit")
echo "Exited"
break
;;
*)
selected_uuid=${UUID_TARGETS["$target"]}
selected_mnt="$target"
;;
esac
done
I'm hoping someone here has an elegant solution for making a menu like this from an associative array. I want to do this in bash without extra packages.
In the end, I still need to assign the correct value to selected_uuid and selected_mnt. The original code does it like this:
selected_uuid="${UUIDS_ARRAY[$((disk))]}"
selected_mnt="${TARGETS_ARRAY[$((disk))]}"
For reference, here is the whole section of original code:
TARGETS="$(findmnt -n -l -t btrfs -o TARGET --list -F /etc/fstab)"
UUIDS="$(findmnt -n -l -t btrfs -o UUID --list -F /etc/fstab)"
declare -a TARGETS_ARRAY
declare -a UUIDS_ARRAY
i=0
disk=-1
disk_count=0
for x in $UUIDS; do
UUIDS_ARRAY[$i]=$x
if [[ "$x" == "$uuid_cmdline" ]]; then
disk=$i
disk_count=$(($disk_count+1))
fi
i=$((i+1))
done
i=0
for x in $TARGETS; do
TARGETS_ARRAY[$i]=$x
i=$((i+1))
done
if [[ "$disk_count" > 1 ]]; then
disk="-1"
fi
if [[ "$disk" == -1 ]]; then
if [[ "$disk_count" == 0 && "$uuid_cmdline" != "none" ]]; then
error "A device with UUID $uuid_cmdline was not found to be mounted, or it is not a BTRFS device."
fi
if [[ -z $ssh ]]; then
printf "Select a mounted BTRFS device on your local machine to backup to.\n"
else
printf "Select a mounted BTRFS device on $remote to backup to.\n"
fi
while [[ $disk -lt 0 || $disk -gt $i ]]; do
for x in "${!TARGETS_ARRAY[@]}"; do
printf "%4s) %s (%s)\n" "$((x+1))" "${UUIDS_ARRAY[$x]}" "${TARGETS_ARRAY[$x]}"
done
printf "%4s) Exit\n" "0"
read -r -p "Enter a number: " disk
if ! [[ $disk == ?(-)+([0-9]) ]]; then
printf "\nNo disk selected. Select a disk to continue.\n"
disk=-1
fi
done
if [[ $disk == 0 ]]; then
exit 0
fi
disk=$(($disk-1))
fi
selected_uuid="${UUIDS_ARRAY[$((disk))]}"
selected_mnt="${TARGETS_ARRAY[$((disk))]}"
printf "\nYou selected the disk with UUID %s.\n" "$selected_uuid" | tee $PIPE
printf "The disk is mounted at %s.\n" "$selected_mnt" | tee $PIPE
123456789abc-def012345-6789abcdef012 (/)and do the "naive select" on that array?