Finds and connects to a UG04 lab machine.

ctl

#!/bin/bash

# will hold available machine hostnames
alive=()

# iterate through a subset of machines in UG04
for suffix in {10..100}; do

    # ping each one
    ping -c 1 -t 1 "cca-ug04-130$suffix" > /dev/null 2>&1

    # if the ping command succeeded, the machine is available
    if [ $? -eq 0 ]; then

        # add it to the list
        alive+=("cca-ug04-130$suffix")
    fi
done

# count the number of available machines
count=${#alive[@]}
echo "Found $count machines."

# pick a machine from the list at random
theChosenOne=${alive[$((RANDOM % $count))]}

# connect to it, accepting any unseen host key
echo "Connecting to $theChosenOne..."
ssh -o StrictHostKeyChecking=no "$theChosenOne"