Add --replace flag to run command

[zueve]

As a developer i need usually quick change environment, without changing .env file. That's why I need replace some parameters by fly.What should i do:

Without -r flag:

devenv run env | grep PORT
PORT=8000

With -r flag:

PORT=5000 devenv run -r 0 env | grep PORT
PORT=8000

[zueve]

#303

[colllin]

Can you just dotenv run PORT=5000 env | grep PORT (move override into [COMMAND] instead of prefixing)? Or I take it you want to override from outer ENV? Then maybe you can do dotenv run PORT=$PORT env | grep PORT?

I’m sorry. Dotenv doesn’t work this way. It doesn’t eval the full command in a sub-shell, like some other similar tools. So in this case it looks for a program named PORT instead of a program named env. In hindsight, this could be an interesting way to solve this problem (as opposed to introducing a new flag). Another idea might be to allow to inline “set” variables, like dotenv run --set PORT=5000 env. Anyway, it’s clear to me now that this is a limitation of dotenv, and I see you’ve already submitted a PR to address it. 🙌

[zueve]

I use python-dotenv in Makefile and sometimes wants to change Environment like:

PORT=1222 make start