mirror of
https://github.com/clap-rs/clap
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26 lines
733 B
Rust
26 lines
733 B
Rust
//! How to use environment variable fallback an how it
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//! interacts with `default_value`.
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use clap::Clap;
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/// Example for allowing to specify options via environment variables.
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#[derive(Clap, Debug)]
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#[clap(name = "env")]
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struct Opt {
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// Use `env` to enable specifying the option with an environment
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// variable. Command line arguments take precedence over env.
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/// URL for the API server
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#[clap(long, env = "API_URL")]
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api_url: String,
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// The default value is used if neither argument nor environment
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// variable is specified.
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/// Number of retries
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#[clap(long, env = "RETRIES", default_value = "5")]
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retries: u32,
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}
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fn main() {
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let opt = Opt::parse();
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println!("{:#?}", opt);
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}
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