I cannot find in the docs how to set this up. Let's say I have
#[derive(Parser, Debug)]
pub struct Opts {
#[clap(long)]
dry_run: bool,
}
What do I need to do to get dry_run from APP_DRY_RUN env variable?
You have to enable the env
feature:
Cargo.toml
...
clap = { version = "...", features = ["env"] }
Then you have to add the env
clap derive option, which will by default read from an ALLCAPS recased env var:
#[derive(Parser, Debug)]
pub struct Opts {
#[clap(long, env)]
dry_run: bool, // --dry-run or DRY_RUN env var
}