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use std::io::Write;
use clap::{Parser, Subcommand};
fn main() -> Result<(), String> {
loop {
let line = readline()?;
let line = line.trim();
if line.is_empty() {
continue;
}
match respond(line) {
Ok(quit) => {
if quit {
break;
}
}
Err(err) => {
write!(std::io::stdout(), "{err}").map_err(|e| e.to_string())?;
std::io::stdout().flush().map_err(|e| e.to_string())?;
}
}
}
Ok(())
}
fn respond(line: &str) -> Result<bool, String> {
let args = shlex::split(line).ok_or("error: Invalid quoting")?;
let cli = Cli::try_parse_from(args).map_err(|e| e.to_string())?;
match cli.command {
Commands::Ping => {
write!(std::io::stdout(), "Pong").map_err(|e| e.to_string())?;
std::io::stdout().flush().map_err(|e| e.to_string())?;
}
Commands::Exit => {
write!(std::io::stdout(), "Exiting ...").map_err(|e| e.to_string())?;
std::io::stdout().flush().map_err(|e| e.to_string())?;
return Ok(true);
}
}
Ok(false)
}
#[derive(Debug, Parser)]
#[command(multicall = true)]
struct Cli {
#[command(subcommand)]
command: Commands,
}
#[derive(Debug, Subcommand)]
enum Commands {
Ping,
Exit,
}
fn readline() -> Result<String, String> {
write!(std::io::stdout(), "$ ").map_err(|e| e.to_string())?;
std::io::stdout().flush().map_err(|e| e.to_string())?;
let mut buffer = String::new();
std::io::stdin()
.read_line(&mut buffer)
.map_err(|e| e.to_string())?;
Ok(buffer)
}