Question

Hello I want to ask a question that is repeated here.

I have four servers in bash script defined like in the code below.
For each server, I want to maintain the ID of the process I have started on it.
Just for testing, I wanted to initialize each array with 10 20 30 40.
And see if I can access these elements as expected. However I cannot access the elements.
Could someone tell me what exactly I am doing wrong.

#!/bin/bash
SERVER_LIST=("server1" "server2" "server3")

for server in ${SERVER_LIST[@]} ; do
    echo $server
    arrayName=$server"process"
    echo $arrayName
    set -a "$arrayName=(10 20 30 40)"
done

current_sever=${SERVER_LIST[0]}
arrayName=$current_server"process"
# The attempt below is failing.
eval "echo Server ${current_server} \${$arrayName[*]}"
echo $(eval echo \${arrayName[*]})Server server1

server1process

It gives me output as follows –

Server server1

server1process

Can someone help please.
Also can you please tell me how to append new element to the array?
I tried the following, but it doesn’t work –

sleep 10 &
arrayName=$current_server"process"
eval "\${$arrayName[*]}+=$!"

Answer 1

Try replacing line 8:

set -a "$arrayName=(10 20 30 40)"

with:

eval "$arrayName=(10 20 30 40)"