How to switch between runtime versions on Bash, Zsh or Fish

example_switching_version_asdf.sh

## Install
asdf plugin add terraform
asdf install terraform 0.13.0
asdf install terraform 0.14.7
asdf install terraform 0.12.29
##

## Command
terraform version
##

## Output
No version set for command terraform
Consider adding one of the following versions in your config file at /tmp/.tool-versions
terraform 0.12.20
terraform 0.12.23
terraform 0.12.24
terraform 0.11.14
terraform 0.12.29
terraform 0.13.0
terraform 0.14.7
## 

## Command
asdf local terraform 0.13.0
terraform version
##

## Output
Your version of Terraform is out of date! The latest version
is 0.14.7. You can update by downloading from https://www.terraform.io/downloads.html
Terraform v0.13.0
##

## Command
cd  ..
asdf global terraform 0.14.7
terraform version
##

## Output
Terraform v0.14.7
##

## Command
asdf shell terraform 0.12.29
terraform version
##

## Output
Terraform v0.12.29

Your version of Terraform is out of date! The latest version
is 0.14.7. You can update by downloading from https://www.terraform.io/downloads.html
##

## Command
declare -p | grep -i terraform
##

## Output
declare -x ASDF_TERRAFORM_VERSION="0.12.29"
##