1 //! Somewhat complex example of usage of structopt.
2
3 use structopt::StructOpt;
4
5 #[derive(StructOpt, Debug)]
6 #[structopt(name = "example")]
7 /// An example of StructOpt usage.
8 struct Opt {
9 // A flag, true if used in the command line.
10 #[structopt(short, long)]
11 /// Activate debug mode
12 debug: bool,
13
14 // An argument of type float, with a default value.
15 #[structopt(short, long, default_value = "42")]
16 /// Set speed
17 speed: f64,
18
19 // Needed parameter, the first on the command line.
20 /// Input file
21 input: String,
22
23 // An optional parameter, will be `None` if not present on the
24 // command line.
25 /// Output file, stdout if not present
26 output: Option<String>,
27
28 // An optional parameter with optional value, will be `None` if
29 // not present on the command line, will be `Some(None)` if no
30 // argument is provided (i.e. `--log`) and will be
31 // `Some(Some(String))` if argument is provided (e.g. `--log
32 // log.txt`).
33 #[structopt(long)]
34 #[allow(clippy::option_option)]
35 /// Log file, stdout if no file, no logging if not present
36 log: Option<Option<String>>,
37
38 // An optional list of values, will be `None` if not present on
39 // the command line, will be `Some(vec![])` if no argument is
40 // provided (i.e. `--optv`) and will be `Some(Some(String))` if
41 // argument list is provided (e.g. `--optv a b c`).
42 #[structopt(long)]
43 optv: Option<Vec<String>>,
44
45 // Skipped option: it won't be parsed and will be filled with the
46 // default value for its type (in this case it'll be an empty string).
47 #[structopt(skip)]
48 skipped: String,
49 }
50
main()51 fn main() {
52 let opt = Opt::from_args();
53 println!("{:?}", opt);
54 }
55