Bash - ssh'ing to hosts in associative array

Question

I am writing a script that stores client connection data such as session ID, server, and port in an associative array. I need to ssh onto these hosts, and run an lsof command to find what process is using this port.

declare -A HOSTMAP
HOSTMAP[session]=$session_ids
HOSTMAP[cname]=$cnames
HOSTMAP[port]=$ports

When printed, data in the array is displayed as so (host names and ports have been changed to protect the innocent)

for g in "${!HOSTMAP[@]}"
do
   printf "[%s]=%s\n" "$g" "${HOSTMAP[$g]}"
done

[cname]=hostname1
hostname2
hostname3
hostname4
hostname5
hostname6
hostname7
hostname8
[session]=44
5
3
9
14
71
65
47
[port]=11111
22222
33333
44444
55555
66666
77777
88888

I would like to do an operation akin to the following:

for session in $session_id
    do
    echo "Discovering application mapped to session ${session} on ${cname}:${port}"
    ssh -tq ${cname} "lsof -Tcp | grep ${port}"
done

Many thanks in advance for advising on an elegant solution

Answer 1

bash doesn't allow nesting of arrays. Here, I would just use separate indexed arrays. However, since your session appears to be an integers, and indexed arrays are sparse, you can use the session id as the index for the cnames and the ports.

cnames=([44]=hostname1 [5]=hostname2 [3]=hostname3)
ports=([44]=1111 [5]=2222 [3]=3333)

for session in "${!cnames[@]}"; do
  cname=${cnames[$session]}
  port=${ports[$session]}
  echo "Discovering application mapped to session ${session} on ${cname}:${port}"
  ssh -tq ${cname} "lsof -Tcp | grep ${port}"
done

Answer 2

You can assign the output of ssh to a variable

result=$(ssh -tq ${cname} "lsof -Tcp | grep ${port}")

Then you can extract the data you want from $result .