```console
$ teller export yaml
FOO_BAR: foo
FOO_BAZ: baz
PRINT_MOOD: happy
PRINT_NAME: linus
$ teller export csv
FOO_BAR,foo
PRINT_NAME,linus
FOO_BAZ,baz
PRINT_MOOD,happy
$ teller export json
{"FOO_BAR":"foo","FOO_BAZ":"baz","PRINT_MOOD":"happy","PRINT_NAME":"linus"}
$ teller export env
FOO_BAR=foo
PRINT_NAME=linus
FOO_BAZ=baz
PRINT_MOOD=happy
$ teller sh
export FOO_BAR='foo'
export PRINT_NAME='linus'
export FOO_BAZ='baz'
export PRINT_MOOD='happy'
$ teller env
FOO_BAR=foo
PRINT_NAME=linus
FOO_BAZ=baz
PRINT_MOOD=happy
```