A crate for creating custom line-oriented command interpreters.

A tour of cmd

cmd consists of three crates:

• cmd: Used for creating the cmd::Cmd struct that contains the CommandHandler implementations as in a HashMap
• command_handler: Contains the CommandHandler trait
• handlers: Contains ready-to-use Quit CommandHandler struct

Example

use std::io;
use std::io::Write;

use cmd::command_handler::CommandHandler;
use cmd::cmd::Cmd;
use cmd::handlers::Quit;


/// CommandHandler that prints out help message
#[derive(Debug, Default)]
pub struct Help;

impl CommandHandler for Help {
fn execute(&self, _stdout: &mut io::Stdout, _args: String) -> usize {
writeln!(_stdout, "Help message").unwrap();
1
}
}

/// CommandHandler that emulates the basic bash touch command to create a new file
#[derive(Debug, Default)]
pub struct Touch;

impl CommandHandler for Touch {
fn execute(&self, _stdout: &mut io::Stdout, _args: String) -> usize {
let filename = _args.split_whitespace().next().unwrap_or_default();

if filename.len() == 0 {
println!("Need to specify a filename");
} else {
let fs_result = std::fs::File::create(filename);
match fs_result {
Ok(file) => println!("Created file: {:?}", file),
Err(_) => println!("Could not create file: {}", filename)
}
}
1
}
}


fn main() -> Result<(), std::io::Error>{
let mut cmd = Cmd::new(
io::BufReader::new(io::stdin()),
io::stdout())
;

let help = Help::default();
let hello = Touch::default();
let quit = Quit::default();

cmd.add_cmd(String::from("help"), Box::new(help))?;
cmd.add_cmd(String::from("touch"), Box::new(hello))?;
cmd.add_cmd(String::from("quit"), Box::new(quit))?;

// cmd.run()?; uncommend to run cmd

Ok(())

}