Custom Environment Variables Setup about cli HOT 3 OPEN

@kudla not sure I understand. What exactly do you want to do ? You can define flag values in a file and have urfave/cli read from there. You can set the ZZZFlag.FilePath

from cli.

	&cli.StringFlag{
		Name:    "some-flag",
		EnvVars: []string{"FLAG_ENV"},
	},

Similar to the way we explicitly provide args into the app

app.Run([]string{"command", "--some-flag", "some-value"})

Could we inject into the app env variables set to be parsed (e.g. FLAG_ENV=some-value) instead of implicit read form os.Environ

I.e. could app be ran in kind of virtual sandbox (args + envs) regardless OS level setup for the process.

from cli.