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|
use std::ffi::OsStr;
use std::io::{self, IsTerminal, Read, Write};
use std::os::unix::ffi::OsStrExt;
use std::os::unix::io::AsRawFd;
use std::path::Path;
use std::process::{Child, Command, Stdio};
pub mod cursor;
pub mod linebuf;
pub mod panic;
pub mod parse;
pub mod raw;
use linebuf::LineBuf;
use raw::*;
use crate::cursor::{Direction, move_cursor};
use crate::parse::Ast;
macro_rules! print {
($($x:tt)*) => {{
write!(io::stdout(), $($x)*).unwrap();
io::stdout().flush().unwrap();
}}
}
macro_rules! println {
() => {{
println!("")
}};
($($x:tt)*) => {{
write!(io::stdout(), $($x)*).unwrap();
write!(io::stdout(), "\r\n").unwrap();
io::stdout().flush().unwrap();
}};
}
const PROMPT: &str = "> ";
fn run_command(raw: &ScopedRawMode, line: Vec<u8>) {
let parsed = parse::do_parse(&line);
let parsed = match parsed {
Ok(p) => p,
Err(err) => {
println!("{line:?}");
print!("{err:?}\r\n{PROMPT}");
return;
}
};
let Ast::Pipes(pipes) = parsed else {
todo!("can only handle pipes");
};
// simple command that can probably be builtin
// TODO: handle builtins uniformly instead of big if case
if pipes.cmds.len() == 1 {
let c = &pipes.cmds[0];
match &c.cmd[..] {
b"cd" => {
let target: &Path = match c.args.get(0).map(|v| &v[..]) {
Some(b"-") => todo!("prev"),
Some(path) => OsStr::from_bytes(path).as_ref(),
None => todo!("homedir"),
};
if let Err(_) = std::env::set_current_dir(target) {
print!("ERR {PROMPT}");
} else {
print!("{PROMPT}");
}
return;
}
b"from" => todo!("read from file"),
b"to" | b"into" => todo!("write into file"),
b"append" => todo!("append to file"),
_ => (),
}
}
let mut children: Vec<Child> = Vec::new();
let mut prev_stdout = None;
let mut spawn_error = false;
raw.disable();
for (i, cmd) in pipes.cmds.iter().enumerate() {
let mut command = Command::new(OsStr::from_bytes(&cmd.cmd));
for arg in cmd.args.iter() {
command.arg(OsStr::from_bytes(arg));
}
if let Some(stdout) = prev_stdout.take() {
command.stdin(Stdio::from(stdout));
}
if i < pipes.cmds.len() - 1 {
command.stdout(Stdio::piped());
}
let mut child = match command.spawn() {
Ok(c) => c,
Err(e) => {
println!("failed to spawn {:?} - {e:?}", OsStr::from_bytes(&cmd.cmd));
spawn_error = true;
break;
}
};
prev_stdout = child.stdout.take();
children.push(child);
}
let status_string;
if spawn_error {
for child in children.iter_mut() {
if let Err(e) = child.kill() {
println!("failed to kill child - {e:?}");
}
}
status_string = "ERR".into();
} else {
let mut code = 0;
for mut child in children {
match child.wait() {
Ok(ec) => {
if let Some(c) = ec.code() {
code = c;
}
}
Err(e) => {
println!("failed to wait for child - {e:?}")
}
}
}
if code == 0 {
status_string = String::new();
} else {
status_string = format!("{code}");
}
}
raw.enable();
print!("\r{status_string}{PROMPT}");
}
fn env_path() {
let path = std::env::var("PATH").unwrap();
for p in path.split(":") {
println!("{p}");
}
}
fn event_loop() {
env_path();
let stdin = io::stdin();
let stdout = io::stdout();
let fd = stdin.as_raw_fd();
let raw = ScopedRawMode::on_fd(fd);
raw.enable();
let mut stdin = stdin.lock();
let mut stdout = stdout.lock();
let mut buffer = [0u8; 1];
let mut line = LineBuf::new();
let mut history = Vec::new();
print!("{PROMPT}");
loop {
let Ok(_) = stdin.read_exact(&mut buffer) else {
break;
};
match buffer[0] {
// EOF
4 => {
break;
}
// Ctrl+L
12 => todo!(),
// Ctrl+R
18 => {
// restart shell
raw.disable();
let _ = Command::new("cargo").arg("run").status();
raw.disable();
std::process::exit(0);
},
// Enter
b'\r' => {
let line = line.dump();
if !line.is_empty() {
print!("\r\n");
history.push(line.clone());
run_command(&raw, line);
}
}
// Backspace (127 on most systems)
127 => {
if line.is_empty() && !line.is_dirty() && !history.is_empty() {
// take previous command for editing
let cmd = history[history.len() - 1].clone();
io::stdout().write_all(&cmd).unwrap();
io::stdout().flush().unwrap();
line.set_content(cmd);
} else if line.del_left().is_some() {
print!("\x08 \x08");
}
}
b'\t' => {
todo!()
}
// Escape sequence
27 => {
let mut seq = [0u8; 2];
stdin.read_exact(&mut seq).unwrap();
if seq[0] == b'[' {
match seq[1] {
b'A' => {
// up
}
b'B' => {
// down
}
b'C' => {
move_cursor(Direction::Right, 1);
line.right();
}
b'D' => {
move_cursor(Direction::Left, 1);
line.left();
}
x => todo!("escape character {x}"),
}
}
}
b'|' if line.is_empty() && !history.is_empty() => {
let mut cmd = history[history.len() - 1].clone();
cmd.extend_from_slice(b" | ");
io::stdout().write_all(&cmd).unwrap();
io::stdout().flush().unwrap();
line.set_content(cmd);
}
// Normal character
x => {
line.add(x);
stdout.write_all(&[x]).unwrap();
line.display_post();
}
}
}
raw.disable();
}
fn main() {
if !io::stdin().is_terminal() {
println!("need to run in a tty");
return;
}
crate::panic::hook();
// it is quite annoying when the terminal window closes due to a crash, so let's just catch all panics
loop {
let res = std::panic::catch_unwind(event_loop);
match res {
Ok(_) => break,
Err(_) => continue,
}
}
println!("bye");
}
|
