BASH function to test what version of AWS CLI you're using.

aws_cli_simple_test.sh

[[ $(aws --version 2>&1) == aws-cli/1* ]] && echo "AWS CLI is V1" || echo "AWS CLI IS > V1"

aws_cli_version_helper.sh

aws_cli_is_v1 () {
  [[ $(aws --version 2>&1) == aws-cli/1* ]] && return 0 || return 1
}

aws_cli_is_v2 () {
  [[ $(aws --version 2>&1) == aws-cli/2* ]] && return 0 || return 1
}

if [[ $(aws_cli_is_v1) ]]; then
  echo "You're using AWS CLI v1"
elif [[ $(aws_cli_is_v2) ]]; then
  echo "You're using AWS VLI v2"
else
  echo "Are you from the future? Or maybe you don't have aws installed?"
fi

# Why is this helpful? I've had an issue where I'm trying to login into docker via ECR. 
# AWS CLI V1 has a completely different docker login command from AWS CLI V2.