yom 2.2.0-part1

// Copyright (C) 2026 The YOM Contributors
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License Version 2 as
// published by the Free Software Foundation.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License Version 2 for more details.
//
// You should have received a copy of the GNU General Public License
// Version 2 along with this program. If not, see
// <https://www.gnu.org/licenses/old-licenses/gpl-2.0.html#SEC1>.

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#[cfg(not(unix))]
compile_error!("YOM is available on UNIX-like systems only.");
// Makes sure YOM dosn't compile on windows

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#[cfg(unix)]
use std::fs::File;
use std::io;
use std::io::Write;
use std::io::{BufRead, BufReader};
mod builtins; // adds all the builtins as a module
mod externals; // adds all the functions for externals as a module
mod internals; // adds all dev functions as a module 
use internals::helpers::*; // adds the dev functions like they were written in this file
use std::process::exit;

fn main() {
    let mut args = std::env::args_os();
    args.next();

    let path = match args.next() {
        Some(p) => p,
        None => return,
    };
    let f = File::open(&path).expect("Expected file");

    let mut input_stack: Vec<BufReader<File>> = Vec::new();
    input_stack.push(BufReader::new(f));

    let mut line = String::new();
    let stdout = io::stdout();
    let mut lock = stdout.lock();
    let mut stderr = std::io::stderr();

    let mut error_continue: bool = true;

    let mut cd_hook: String = "".into();
    let mut echo_hook: String = "".into();
    let mut exit_hook: String = "".into();
    let mut pwd_hook: String = "".into();
    let mut read_hook: String = "".into();
    let mut core_hook: String = "".into();
    let mut eval_hook: String = "".into();

    while !input_stack.is_empty() {
        let bytes = input_stack
            .last_mut()
            .unwrap()
            .read_line(&mut line)
            .unwrap();

        if bytes == 0 {
            input_stack.pop();
            continue;
        }

        line = line.trim().into();
        eval::<false, _, _>(
            &mut line,
            &mut input_stack,
            &mut lock,
            &mut stderr,
            &mut error_continue,
            &mut cd_hook,
            &mut echo_hook,
            &mut exit_hook,
            &mut pwd_hook,
            &mut read_hook,
            &mut core_hook,
            &mut eval_hook,
        );
    }

    if !core_hook.is_empty() {
        use std::env;
        use std::fs;
        use std::os::unix::net::UnixListener;
        use std::process::{Command, Stdio};

        let mut core = Command::new(&core_hook)
            .arg("core")
            .stdin(Stdio::inherit())
            .stdout(Stdio::inherit())
            .stderr(Stdio::inherit())
            .spawn()
            .expect("Failed to start the core process binary");

        let socket_path = "/tmp/yom_core.sock";
        let _ = fs::remove_file(socket_path);

        let listener = match UnixListener::bind(socket_path) {
            Ok(listener) => listener,
            Err(_) => {
                err_write("failed to bind to socket_path", &mut stderr);
                let _ = fs::remove_file(socket_path);
                exit(1);
            }
        };

        let (stream, _address) = listener
            .accept()
            .expect("Failed to accept an incoming client connection");

        let mut old_cwd = env::current_dir().expect("Failed to get current working directory");

        let mut stream_clone = stream.try_clone().expect("Failed to clone stream");
        let mut reader = io::BufReader::new(stream);
        let mut line_buf = String::new();

        loop {
            line_buf.clear();
            match reader.read_line(&mut line_buf) {
                Ok(0) => {
                    let _ = std::fs::remove_file("/tmp/yom_core.sock");

                    match core.wait() {
                        Ok(status) => {
                            if let Some(code) = status.code() {
                                exit(code);
                            } else {
                                let _ = write!(stderr, "core was terminated by a signal\n");
                            }
                        }

                        Err(_) => { 
                            err_write("failed to get core's exit code", &mut stderr);
                            let _ = write!(stderr, "defaulting to code 0\n");
                            exit(0);
                        }
                    }
                }
                Ok(_) => {
                    let incoming = line_buf.trim();
                    if incoming.starts_with("eval ") {
                        let mut core_line = incoming.strip_prefix("eval ").unwrap().to_string();
                        eval_call(
                            &mut core_line,
                            &mut input_stack,
                            &mut lock,
                            &mut stderr,
                            &mut error_continue,
                            &mut cd_hook,
                            &mut echo_hook,
                            &mut exit_hook,
                            &mut pwd_hook,
                            &mut read_hook,
                            &mut core_hook,
                            &mut eval_hook,
                        );

                        let cwd =
                            env::current_dir().expect("Failed to get current working directory");
                        if old_cwd != cwd {
                            old_cwd = cwd.clone();
                            let cwd_string = format!(":{}\n", cwd.to_string_lossy());
                            let _ = stream_clone.write_all(cwd_string.as_bytes());
                        } else {
                            let _ = stream_clone.write_all(b"C\n");
                        }
                    }
                }
                Err(_) => {
                    err_write("[FATAL] STREAM READ ERROR", &mut stderr);
                    exit(2);
                }
            }
        }
    } else {
        return;
    }
}

#[inline(never)]
fn eval_call<W: Write, E: Write>(
    mut line: &mut String,
    input_stack: &mut Vec<BufReader<File>>,
    mut lock: &mut W,
    mut stderr: &mut E,
    error_continue: &mut bool,
    cd_hook: &mut String,
    echo_hook: &mut String,
    exit_hook: &mut String,
    pwd_hook: &mut String,
    read_hook: &mut String,
    core_hook: &mut String,
    eval_hook: &mut String,
) {
    eval::<true, W, E>(
        &mut line,
        input_stack,
        &mut lock,
        &mut stderr,
        error_continue,
        cd_hook,
        echo_hook,
        exit_hook,
        pwd_hook,
        read_hook,
        core_hook,
        eval_hook,
    )
}

#[inline(always)]
fn eval<const NO_INLINE: bool, W: Write, E: Write>(
    mut line: &mut String,
    input_stack: &mut Vec<BufReader<File>>,
    mut lock: &mut W,
    mut stderr: &mut E,
    error_continue: &mut bool,
    cd_hook: &mut String,
    echo_hook: &mut String,
    exit_hook: &mut String,
    pwd_hook: &mut String,
    read_hook: &mut String,
    core_hook: &mut String,
    eval_hook: &mut String
) {
    let status = exec_hooks(eval_hook, "eval", line, error_continue, &mut stderr);
    if status == 0 { 
        line.clear(); 
        return; 
    }

    if line.starts_with("#") || line == "" {
        // ignores line
        line.clear();
        return;
    } else if line == "then" {
        // ignores line
        line.clear();
        return;
    } else if line == "fi" {
        // ignores line
        line.clear();
        return;
    } else if line.starts_with(". ") || line.starts_with("source ") {
        let mut parts = line.split_whitespace();
        parts.next(); // skip "." or "source"
        if let Some(path) = parts.next() {
            let f = File::open(path).expect("Expected file");
            input_stack.push(BufReader::new(f));
        } else {
            err_write("source requires a path", &mut stderr);
            if !*error_continue {
                exit(1);
            }
        }
        line.clear();
        return;
    } else if line.starts_with("/") || line.starts_with("$") {
        if line.ends_with(" &") {
            externals::entry::background(line.strip_suffix(" &").unwrap()); // lets the program continue (ignoring the zombie)
            line.clear();
            return;
        } else {
            externals::entry::waitfor(line.as_str()); // waits for the program to finish
            line.clear();
            return;
        }
    } else if line.starts_with("set ") {
        let options = line.strip_prefix("set ").unwrap();
        let mut flag = ' ';
        if let Some(c) = options.chars().next() {
            flag = c;
        } else {
            err_write("no flag included in set", &mut stderr);
            if !*error_continue {
                exit(1);
            }
        }
        let options = options.strip_prefix("-").unwrap_or(options);
        let options = options.strip_prefix("+").unwrap_or(options);
        if options.contains("e") {
            if flag == '+' {
                *error_continue = true;
            } else if flag == '-' {
                *error_continue = false;
            }
        } else {
            err_write("you missed (or mispelt) an option in set", &mut stderr);
            if !*error_continue {
                exit(1);
            }
        }
        line.clear();
        return;
    } else if line.starts_with('e') {
        if line.starts_with("exec ") {
            externals::entry::exec(line.as_str()); // changes yom into said program
            err_write("exec failed to overwrite process", &mut stderr);
            if !*error_continue {
                exit(1);
            }
            line.clear();
            return;
        } else if line.starts_with("echo ") {
            // echos the string back to you
            let str = line.strip_prefix("echo ").unwrap(); // removes the string "echo " from the start
            if str.starts_with('"') && str.ends_with('"') {
                // does a bit of trimming for quotes
                let str = str.strip_prefix('"').unwrap();
                let str = str.strip_suffix('"').unwrap();
                builtins::echo::echo(str, &mut lock, &echo_hook, &mut stderr, *error_continue); // calls echo (handing the stdout lock over)
                line.clear();
                return;
            } else {
                builtins::echo::echo(str, &mut lock, &echo_hook, &mut stderr, *error_continue); // calls echo (handing the stdout lock over)
                line.clear();
                return;
            }
        } else if line.starts_with("export ") {
            let tmp = line.strip_prefix("export ").unwrap();

            if let Some((name, data)) = tmp.split_once('=') {
                unsafe {
                    let split = shell_words::split(data).expect("Invalid command syntax");
                    let data: String = split.join(" ");
                    std::env::set_var(name, data);
                }
            }
            line.clear();
            return;
        } else {
            err_write("syntax error", &mut stderr);
            if !*error_continue {
                exit(1);
            }
            line.clear();
            return;
        }
    } else if line.starts_with("cd ") {
        let dir = line.strip_prefix("cd ").unwrap(); // trims the "cd " string from the dir
        if dir.starts_with('"') && dir.ends_with('"') {
            let dir = dir.strip_prefix('"').unwrap(); // trims quotes from start shadowing old dir
            let dir = dir.strip_suffix('"').unwrap(); // trims quotes from start shadowing old dir
            let _ = builtins::cd::cd(dir, &cd_hook, &mut stderr, *error_continue); // calls cd 
            line.clear();
            return;
        } else {
            let _ = builtins::cd::cd(dir, &cd_hook, &mut stderr, *error_continue); // calls cd 
            line.clear();
            return;
        }
    } else if line == "pwd" {
        // echos the current working directory to stdout
        let _ = builtins::pwd::pwd(&mut lock, &mut stderr, &pwd_hook); // calls pwd (handing stdout lock over)
        line.clear();
        return;
    } else if line.starts_with("read") {
        let prompt = line.strip_prefix("read ").unwrap(); // removes the string "read " from the prompt
        if prompt.starts_with('"') && prompt.ends_with('"') {
            let prompt = prompt.strip_prefix('"').unwrap(); // trims quotes
            let prompt = prompt.strip_suffix('"').unwrap(); // trims quotes while shadowing old prompt
            let val = builtins::read::read(prompt, &read_hook); // executes read
            unsafe {
                std::env::set_var(prompt, val);
            }
            line.clear();
            return;
        } else {
            let val = builtins::read::read(prompt, &read_hook); // executes read
            unsafe {
                std::env::set_var(prompt, val);
            }
            line.clear();
            return;
        }
    } else if line == "exit" {
        builtins::exit::exit(0, &exit_hook, &mut stderr, *error_continue); // calls exit on exit code 0
        line.clear();
        return;
    } else if line.starts_with("exit ") {
        let code = line.strip_prefix("exit ").unwrap();
        let val = str_or_int(code, code);
        if val == true {
            let code: i32 = code.parse().unwrap_or(1); // trims "exit " and the newline, then parses it into i32
            builtins::exit::exit(code, &exit_hook, &mut stderr, *error_continue); // executes exit on exit code specified in the file
            line.clear();
            return;
        } else {
            err_write("exit requires an integer", &mut stderr);
            if !*error_continue {
                exit(1);
            }
            line.clear();
            return;
        }
    } else if line.starts_with("if [") {
        let split = shell_words::split(&line).unwrap();
        let left: &str = &split[2];
        let operator: &str = &split[3];
        let right: &str = &split[4];

        let mut indent: i64 = 1;

        // checking if it is a env variable
        if left.starts_with("$") || right.starts_with("$") {
            let tmp = left.strip_prefix("$").unwrap_or(left);
            let left = std::env::var_os(tmp).unwrap_or(tmp.into());
            let left = left.to_str().expect("Not valid UTF-8");

            let tmp = right.strip_prefix("$").unwrap_or(right);
            let right = std::env::var_os(tmp).unwrap_or(tmp.into());
            let right = right.to_str().expect("Not valid UTF-8");

            let val = str_or_int(left, right);

            if val == true {
                let left: i64 = left.parse().unwrap();
                let right: i64 = right.parse().unwrap();
                let val = ncmp(left, right, operator);

                if val == true {
                    line.clear();
                    return;
                } else {
                    line.clear();

                    while input_stack
                        .last_mut()
                        .unwrap()
                        .read_line(&mut line)
                        .unwrap()
                        > 0
                    {
                        let trimmed = line.trim();
                        if trimmed.starts_with("if [") {
                            indent += 1;
                        }

                        if trimmed == "fi" {
                            line.clear();
                            indent -= 1;
                        }

                        if indent == 0 {
                            line.clear();
                            break;
                        }
                        line.clear();
                    }
                }
            } else {
                let val = strcmp(left, right, operator);

                if val == true {
                    line.clear();
                    return;
                } else {
                    line.clear();

                    while input_stack
                        .last_mut()
                        .unwrap()
                        .read_line(&mut line)
                        .unwrap()
                        > 0
                    {
                        let trimmed = line.trim();
                        if trimmed.starts_with("if [") {
                            indent += 1;
                        }

                        if trimmed == "fi" {
                            line.clear();
                            indent -= 1;
                        }

                        if indent == 0 {
                            line.clear();
                            break;
                        }
                        line.clear();
                    }
                }
                return;
            }
        } else {
            let val = str_or_int(left, right);

            if val == true {
                let left: i64 = left.parse().unwrap();
                let right: i64 = right.parse().unwrap();
                let val = ncmp(left, right, operator);

                if val == true {
                    line.clear();
                    return;
                } else {
                    line.clear();

                    while input_stack
                        .last_mut()
                        .unwrap()
                        .read_line(&mut line)
                        .unwrap()
                        > 0
                    {
                        let trimmed = line.trim();
                        if trimmed.starts_with("if [") {
                            indent += 1;
                        }

                        if trimmed == "fi" {
                            line.clear();
                            indent -= 1;
                        }

                        if indent == 0 {
                            line.clear();
                            break;
                        }
                        line.clear();
                    }
                }
                return;
            } else {
                let val = strcmp(left, right, operator);

                if val == true {
                    line.clear();
                    return;
                } else {
                    line.clear();

                    while input_stack
                        .last_mut()
                        .unwrap()
                        .read_line(&mut line)
                        .unwrap()
                        > 0
                    {
                        let trimmed = line.trim();
                        if trimmed.starts_with("if [") {
                            indent += 1;
                        }

                        if trimmed == "fi" {
                            line.clear();
                            indent -= 1;
                        }

                        if indent == 0 {
                            line.clear();
                            break;
                        }
                        line.clear();
                    }
                }
            }
        }
        line.clear();
        return;
    } else if line.starts_with("hook ") {
        let split = shell_words::split(&line).unwrap();
        let injected: &str = &split[1];
        let path = &split[2..];
        let mut path: String = path.join("");
        if path.starts_with("~/") {
            path = path.strip_prefix("~").unwrap().to_string();
            if let Some(home_path) = home::home_dir() {
                if let Some(home_str) = home_path.to_str() {
                    path.insert_str(0, home_str);
                }
            }
        }

        if injected == "cd" {
            *cd_hook = path
        } else if injected == "echo" {
            *echo_hook = path;
        } else if injected == "exit" {
            *exit_hook = path;
        } else if injected == "pwd" {
            *pwd_hook = path;
        } else if injected == "read" {
            *read_hook = path;
        } else if injected == "core" {
            *core_hook = path;
        } else if injected == "builtins" {
            *cd_hook = path.to_owned();
            *echo_hook = path.to_owned();
            *exit_hook = path.to_owned();
            *pwd_hook = path.to_owned();
            *read_hook = path.to_owned();
        } else if injected == "eval" {
            eval_hook.push_str(&path);
        } else {
            err_write("hook not valid", stderr);
            if !*error_continue {
                exit(1);
            }
        }

        line.clear();
        return;
    } else {
        err_write("syntax error", &mut stderr);
        if !*error_continue {
            exit(1);
        }
        line.clear();
        return;
    }
}