coreutils/src/uucore/coreopts.rs

extern crate getopts;
use std::io::Write;

pub struct HelpText<'a> {
    pub name : &'a str,
    pub version : &'a str,
    pub syntax : &'a str,
    pub summary : &'a str,
    pub long_help : &'a str,
    pub display_usage : bool
}

pub struct CoreOptions<'a> {
    options : getopts::Options,
    help_text : HelpText<'a>
}

impl<'a> CoreOptions<'a> {
    pub fn new(help_text: HelpText<'a>) -> Self {
        let mut ret = CoreOptions {
            options : getopts::Options::new(),
            help_text : help_text
        };
        ret.options
            .optflag("", "help", "print usage information")
            .optflag("", "version", "print name and version number");
        ret
    }
    pub fn optopt(&mut self, short_name: &str, long_name: &str, desc: &str, hint: &str) -> &mut CoreOptions<'a> {
        self.options.optopt(short_name, long_name, desc, hint);
        self
    }
    pub fn optflag(&mut self, short_name: &str, long_name: &str, desc: &str) -> &mut CoreOptions<'a> {
        self.options.optflag(short_name, long_name, desc);
        self
    }
    pub fn usage(&self, summary : &str) -> String {
        self.options.usage(summary)
    }
    pub fn parse(&mut self, args : Vec<String>) -> getopts::Matches {
        let matches = match self.options.parse(&args[1..]) {
            Ok(m) => { Some(m) },
            Err(f) => {
                crash!(1, "{}", f);
            }
        }.unwrap();
        if matches.opt_present("help") {            
            let usage_str = if self.help_text.display_usage {
                    format!("\n {}\n\n Reference\n", 
                        self.options.usage(self.help_text.summary)
                    ).replace("Options:", " Options:") 
                } else { String::new() };
            print!("
 {0} {1}

 {0} {2}
{3}{4}
", self.help_text.name, self.help_text.version, self.help_text.syntax, usage_str, self.help_text.long_help);
            exit!(0);
        } else if matches.opt_present("version") {
            println!("{} {}", self.help_text.name, self.help_text.version);
            exit!(0);
        }
        matches
    }
}

#[macro_export]
macro_rules! new_coreopts { 
    ($syntax: expr, $summary: expr, $long_help: expr) => (
        uucore::coreopts::CoreOptions::new(uucore::coreopts::HelpText {
            name: executable!(),
            version: env!("CARGO_PKG_VERSION"),
            syntax: $syntax,
            summary: $summary,
            long_help: $long_help,
            display_usage: true
        })
    );
    ($syntax: expr, $summary: expr, $long_help: expr, $display_usage: expr) => (
        uucore::coreopts::CoreOptions::new(uucore::coreopts::HelpText {
            name: executable!(),
            version: env!("CARGO_PKG_VERSION"),
            syntax: $syntax,
            summary: $summary,
            long_help: $long_help,
            display_usage: $display_usage
        })
    );
}