# pda function cross-references another key
$ pda set base https://example.com
$ fecho tpl1 {{ pda "base" }}/api
$ pda set endpoint@tplr < tpl1
$ pda get endpoint@tplr
https://example.com/api
# pda with substitution vars passed through
$ fecho tpl2 Hello, {{ default "World" .NAME }}
$ pda set greeting@tplr < tpl2
$ fecho tpl3 {{ pda "greeting@tplr" }}!
$ pda set shout@tplr < tpl3
$ pda get shout@tplr NAME=Alice
Hello, Alice!