sign automatic number to my file in bash - bash

Question

I am trying to assign a unique number to my strings that are redirected and stored in a file.
You have to fill in a form, and I want to send a unique number with it.
example:
echo fill in the form
echo place
read place
date
"place: $place, time $(date) >> List
It has to look something like this.
outcome in List
number 1, place, time
number 2, place, time
number 3, place, time
I used a loop but I got the following outcome.
number 0, place, time
number 0, place, time.
I think I need a function that checks the last number given in the file and add 1 to it, but I wonder if there is an easier way.

Answer 1

Perhaps this one:
#!/bin/bash
# Optionally truncate file
# : > List
I=0
while
read -p "Place: " PLACE
read -p "Time: " TIME
echo "number $((++I)), $PLACE, $TIME" >> List
read -n 1 -p "Continue? " && [[ $REPLY == [yY] ]]
do
continue
done
Update:
#!/bin/bash
# Optionally truncate file
# : > List
shopt -s extglob
for (( I = 1;; ++I )); do
for (( ;; )); do
read -p "Place: " PLACE
read -p "Time: " TIME
until
read -p "Save data? "
[[ $REPLY == [nN]?([oO]) ]]
do
[[ $REPLY == [yY]?([eE][sS]) ]] && break 2
echo "Please answer Y[es] or N[o]."
done
done
echo "Saving \"number $I, $PLACE, $TIME\"."
echo "number $I, $PLACE, $TIME" >> List
until
read -p "Continue? "
[[ $REPLY == [yY]?([eE][sS]) ]]
do
[[ $REPLY == [nN]?([oO]) ]] && break 2
echo "Please answer Y[es] or N[o]."
done
echo
done

Answer 2

To generate a 16-char random hex string, you can use r=$(openssl rand -hex 8)
To find the last number used and increment it, you can do
prev=$(awk -F, 'END {print $1}' List)
printf "%d, place:%s, time:%s\n" $((prev+1)) "$place" "$(date)" >> List
This is subject to a race condition if the script can be executed simultaneously
To start at 1:
if [[ ! -f List ]]; then
prev=1
else
prev=$(awk -F, 'END {print $1}' List)
fi
printf "%d, place:%s, time:%s\n" $((prev+1)) "$place" "$(date)" >> List