paiza.ioでrust その18

概要

paiza.ioでrustやってみた。
shell見つけたので、やってみた。

参考にしたページ

サンプルコード

use std::{
    env,
    io::{stdin, stdout, Write},
    path::Path,
    process::{Child, Command, Stdio},
};

fn main() {
    loop {
        print!("> ");
        stdout().flush().unwrap();
        let mut input = String::new();
        stdin().read_line(&mut input).unwrap();
        let mut commands = input.trim().split("|").peekable();
        let mut previous_command = None;
        while let Some(command) = commands.next() 
        {
            let mut parts = command.trim().split_whitespace();
            let command = parts.next().unwrap();
            let args = parts;
            match command {
                "cd" => {
                    let new_dir = args.peekable().peek().map_or("/", |x| *x);
                    let root = Path::new(new_dir);
                    if let Err(e) = env::set_current_dir(&root) {
                        eprintln!("{}", e);
                    }
                    previous_command = None;
                }
                "exit" => return,
                command => {
                    let stdin = previous_command.map_or(Stdio::inherit(), |output: Child| {
                        Stdio::from(output.stdout.unwrap())
                    });
                    let stdout = if commands.peek().is_some() 
                    {
                        Stdio::piped()
                    } 
                    else 
                    {
                        Stdio::inherit()
                    };
                    let output = Command::new(command)
                        .args(args)
                        .stdin(stdin)
                        .stdout(stdout)
                        .spawn();
                    match output {
                        Ok(output) => {
                            previous_command = Some(output);
                        }
                        Err(e) => {
                            previous_command = None;
                            eprintln!("{}", e);
                        }
                    };
                }
            }
        }
        if let Some(mut final_command) = previous_command 
        {
            final_command.wait().unwrap();
        }
    }
}

投入したソース

ls
pwd
exit

実行結果

> build_command
build_exit_code.txt
build_stderr.txt
build_stdout.txt
build_time.txt
exec_command
exec_stderr.txt
exec_stdin.txt
exec_stdout.txt
Main
Main.rs
main.tar.gz
runner_mysql
run_user
> /workspace
> 

成果物

以上。