switch_ec2_creds.sh

#!/bin/bash
BASE_DIRECTORY=$HOME/opt/ec2/credentials/


function outputChoices {
    local count=0
    for directory in ${directories[@]}
    do
        echo -e "$count:\t$(basename $directory)"
        ((count++))
    done

    echo -n "Select one of [0-$numberOfDirectories] - any other input leaves creds unchanged:  "
}

function changeCredDirectory {
    if [[ -n $(echo -n $inputChoice | grep '^[0-9][0-9]*$')  && $inputChoice -ge 0 && $inputChoice -le $numberOfDirectories ]]
    then
        newCredDirectory=${directories[$inputChoice]} 
        ln -nsf $newCredDirectory $BASE_DIRECTORY/current
        echo; echo "Credentials set to $newCredDirectory"
    else
        echo ;echo "Invalid selection - creds unchanged"
    fi
}

alias echo="echo -e"
directories=($(find $BASE_DIRECTORY -type d -maxdepth 1 -mindepth 1))
numberOfDirectories=$(( ${#directories[@]} - 1 ))
outputChoices
read inputChoice
changeCredDirectory 
unalias echo