// include the latest version of the regex crate in your Cargo.toml
extern crate regex;
use regex::Regex;
fn main() {
let regex = Regex::new(r"(?i)(?:^|\n)([^\n]*options:[^\n]*(?=\n?)(?:\n+[ \t].*?(?=\n|$))*)").unwrap();
let string = "Usage:
diagrammer [--debug] [--output=<file>] <input-file>
diagrammer --help
Options:
--debug, -d Draw the diagram upon a grid.
--help Show this message and exit.
--output=<file> Place output in file 'file'. [default: output.png]
Copyright Evgeny Gagauz, 2016.
";
// result will be a tuple containing the start and end indices for the first match in the string
let result = regex.captures(string);
let (start, end) = match result {
Some((s, e)) => (s, e),
None => {
// ...
}
};
println!("{}", &string[start, end]);
}
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Rust, please visit: https://docs.rs/regex/latest/regex/