Move all functions of main.rs into modules (#7803)

The affected modules are:
- `command.rs`
- `config_files.rs`
- `terminal.rs`

src/command.rs

@@ -0,0 +1,300 @@
+use nu_cli::report_error;
+use nu_engine::{get_full_help, CallExt};
+use nu_parser::parse;
+use nu_protocol::{
+    ast::{Call, Expr, Expression, PipelineElement},
+    engine::{Command, EngineState, Stack, StateWorkingSet},
+    Category, Example, IntoPipelineData, PipelineData, ShellError, Signature, Spanned, SyntaxShape,
+    Value,
+};
+use nu_utils::stdout_write_all_and_flush;
+
+pub(crate) fn parse_commandline_args(
+    commandline_args: &str,
+    engine_state: &mut EngineState,
+) -> Result<NushellCliArgs, ShellError> {
+    let (block, delta) = {
+        let mut working_set = StateWorkingSet::new(engine_state);
+        working_set.add_decl(Box::new(Nu));
+
+        let (output, err) = parse(
+            &mut working_set,
+            None,
+            commandline_args.as_bytes(),
+            false,
+            &[],
+        );
+        if let Some(err) = err {
+            report_error(&working_set, &err);
+
+            std::process::exit(1);
+        }
+
+        working_set.hide_decl(b"nu");
+        (output, working_set.render())
+    };
+
+    engine_state.merge_delta(delta)?;
+
+    let mut stack = Stack::new();
+
+    // We should have a successful parse now
+    if let Some(pipeline) = block.pipelines.get(0) {
+        if let Some(PipelineElement::Expression(
+            _,
+            Expression {
+                expr: Expr::Call(call),
+                ..
+            },
+        )) = pipeline.elements.get(0)
+        {
+            let redirect_stdin = call.get_named_arg("stdin");
+            let login_shell = call.get_named_arg("login");
+            let interactive_shell = call.get_named_arg("interactive");
+            let commands: Option<Expression> = call.get_flag_expr("commands");
+            let testbin: Option<Expression> = call.get_flag_expr("testbin");
+            #[cfg(feature = "plugin")]
+            let plugin_file: Option<Expression> = call.get_flag_expr("plugin-config");
+            let config_file: Option<Expression> = call.get_flag_expr("config");
+            let env_file: Option<Expression> = call.get_flag_expr("env-config");
+            let log_level: Option<Expression> = call.get_flag_expr("log-level");
+            let log_target: Option<Expression> = call.get_flag_expr("log-target");
+            let execute: Option<Expression> = call.get_flag_expr("execute");
+            let threads: Option<Value> = call.get_flag(engine_state, &mut stack, "threads")?;
+            let table_mode: Option<Value> =
+                call.get_flag(engine_state, &mut stack, "table-mode")?;
+
+            fn extract_contents(
+                expression: Option<Expression>,
+            ) -> Result<Option<Spanned<String>>, ShellError> {
+                if let Some(expr) = expression {
+                    let str = expr.as_string();
+                    if let Some(str) = str {
+                        Ok(Some(Spanned {
+                            item: str,
+                            span: expr.span,
+                        }))
+                    } else {
+                        Err(ShellError::TypeMismatch("string".into(), expr.span))
+                    }
+                } else {
+                    Ok(None)
+                }
+            }
+
+            let commands = extract_contents(commands)?;
+            let testbin = extract_contents(testbin)?;
+            #[cfg(feature = "plugin")]
+            let plugin_file = extract_contents(plugin_file)?;
+            let config_file = extract_contents(config_file)?;
+            let env_file = extract_contents(env_file)?;
+            let log_level = extract_contents(log_level)?;
+            let log_target = extract_contents(log_target)?;
+            let execute = extract_contents(execute)?;
+
+            let help = call.has_flag("help");
+
+            if help {
+                let full_help = get_full_help(
+                    &Nu.signature(),
+                    &Nu.examples(),
+                    engine_state,
+                    &mut stack,
+                    true,
+                );
+
+                let _ = std::panic::catch_unwind(move || stdout_write_all_and_flush(full_help));
+
+                std::process::exit(1);
+            }
+
+            if call.has_flag("version") {
+                let version = env!("CARGO_PKG_VERSION").to_string();
+                let _ = std::panic::catch_unwind(move || {
+                    stdout_write_all_and_flush(format!("{}\n", version))
+                });
+
+                std::process::exit(0);
+            }
+
+            return Ok(NushellCliArgs {
+                redirect_stdin,
+                login_shell,
+                interactive_shell,
+                commands,
+                testbin,
+                #[cfg(feature = "plugin")]
+                plugin_file,
+                config_file,
+                env_file,
+                log_level,
+                log_target,
+                execute,
+                threads,
+                table_mode,
+            });
+        }
+    }
+
+    // Just give the help and exit if the above fails
+    let full_help = get_full_help(
+        &Nu.signature(),
+        &Nu.examples(),
+        engine_state,
+        &mut stack,
+        true,
+    );
+    print!("{}", full_help);
+    std::process::exit(1);
+}
+
+pub(crate) struct NushellCliArgs {
+    pub(crate) redirect_stdin: Option<Spanned<String>>,
+    pub(crate) login_shell: Option<Spanned<String>>,
+    pub(crate) interactive_shell: Option<Spanned<String>>,
+    pub(crate) commands: Option<Spanned<String>>,
+    pub(crate) testbin: Option<Spanned<String>>,
+    #[cfg(feature = "plugin")]
+    pub(crate) plugin_file: Option<Spanned<String>>,
+    pub(crate) config_file: Option<Spanned<String>>,
+    pub(crate) env_file: Option<Spanned<String>>,
+    pub(crate) log_level: Option<Spanned<String>>,
+    pub(crate) log_target: Option<Spanned<String>>,
+    pub(crate) execute: Option<Spanned<String>>,
+    pub(crate) threads: Option<Value>,
+    pub(crate) table_mode: Option<Value>,
+}
+
+#[derive(Clone)]
+struct Nu;
+
+impl Command for Nu {
+    fn name(&self) -> &str {
+        "nu"
+    }
+
+    fn signature(&self) -> Signature {
+        let mut signature = Signature::build("nu")
+            .usage("The nushell language and shell.")
+            .named(
+                "commands",
+                SyntaxShape::String,
+                "run the given commands and then exit",
+                Some('c'),
+            )
+            .named(
+                "execute",
+                SyntaxShape::String,
+                "run the given commands and then enter an interactive shell",
+                Some('e'),
+            )
+            .switch("interactive", "start as an interactive shell", Some('i'))
+            .switch("login", "start as a login shell", Some('l'))
+            .named(
+                "table-mode",
+                SyntaxShape::String,
+                "the table mode to use. rounded is default.",
+                Some('m'),
+            )
+            .named(
+                "threads",
+                SyntaxShape::Int,
+                "threads to use for parallel commands",
+                Some('t'),
+            )
+            .switch("version", "print the version", Some('v'))
+            .named(
+                "config",
+                SyntaxShape::String,
+                "start with an alternate config file",
+                None,
+            )
+            .named(
+                "env-config",
+                SyntaxShape::String,
+                "start with an alternate environment config file",
+                None,
+            );
+
+        #[cfg(feature = "plugin")]
+        {
+            signature = signature.named(
+                "plugin-config",
+                SyntaxShape::String,
+                "start with an alternate plugin signature file",
+                None,
+            );
+        }
+
+        signature = signature
+            .named(
+                "log-level",
+                SyntaxShape::String,
+                "log level for diagnostic logs (error, warn, info, debug, trace). Off by default",
+                None,
+            )
+            .named(
+                "log-target",
+                SyntaxShape::String,
+                "set the target for the log to output. stdout, stderr(default), mixed or file",
+                None,
+            )
+            .switch(
+                "stdin",
+                "redirect standard input to a command (with `-c`) or a script file",
+                None,
+            )
+            .named(
+                "testbin",
+                SyntaxShape::String,
+                "run internal test binary",
+                None,
+            )
+            .optional(
+                "script file",
+                SyntaxShape::Filepath,
+                "name of the optional script file to run",
+            )
+            .rest(
+                "script args",
+                SyntaxShape::String,
+                "parameters to the script file",
+            )
+            .category(Category::System);
+
+        signature
+    }
+
+    fn usage(&self) -> &str {
+        "The nushell language and shell."
+    }
+
+    fn run(
+        &self,
+        engine_state: &EngineState,
+        stack: &mut Stack,
+        call: &Call,
+        _input: PipelineData,
+    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
+        Ok(Value::String {
+            val: get_full_help(&Nu.signature(), &Nu.examples(), engine_state, stack, true),
+            span: call.head,
+        }
+        .into_pipeline_data())
+    }
+
+    fn examples(&self) -> Vec<nu_protocol::Example> {
+        vec![
+            Example {
+                description: "Run a script",
+                example: "nu myfile.nu",
+                result: None,
+            },
+            Example {
+                description: "Run nushell interactively (as a shell or REPL)",
+                example: "nu",
+                result: None,
+            },
+        ]
+    }
+}

src/config_files.rs

@@ -1,4 +1,6 @@
 use log::info;
+#[cfg(feature = "plugin")]
+use nu_cli::read_plugin_file;
 use nu_cli::{eval_config_contents, eval_source, report_error};
 use nu_parser::ParseError;
 use nu_path::canonicalize_with;
@@ -7,6 +9,7 @@ use nu_protocol::{PipelineData, Spanned};
 use nu_utils::{get_default_config, get_default_env};
 use std::fs::File;
 use std::io::Write;
+use std::path::Path;
 
 pub(crate) const NUSHELL_FOLDER: &str = "nushell";
 const CONFIG_FILE: &str = "config.nu";
@@ -190,3 +193,53 @@ fn eval_default_config(
         }
     }
 }
+
+pub(crate) fn setup_config(
+    engine_state: &mut EngineState,
+    stack: &mut Stack,
+    #[cfg(feature = "plugin")] plugin_file: Option<Spanned<String>>,
+    config_file: Option<Spanned<String>>,
+    env_file: Option<Spanned<String>>,
+    is_login_shell: bool,
+) {
+    #[cfg(feature = "plugin")]
+    read_plugin_file(engine_state, stack, plugin_file, NUSHELL_FOLDER);
+
+    info!("read_config_file {}:{}:{}", file!(), line!(), column!());
+
+    read_config_file(engine_state, stack, env_file, true);
+    read_config_file(engine_state, stack, config_file, false);
+
+    if is_login_shell {
+        read_loginshell_file(engine_state, stack);
+    }
+
+    // Give a warning if we see `$config` for a few releases
+    {
+        let working_set = StateWorkingSet::new(engine_state);
+        if working_set.find_variable(b"$config").is_some() {
+            println!("warning: use `let-env config = ...` instead of `let config = ...`");
+        }
+    }
+}
+
+pub(crate) fn set_config_path(
+    engine_state: &mut EngineState,
+    cwd: &Path,
+    default_config_name: &str,
+    key: &str,
+    config_file: &Option<Spanned<String>>,
+) {
+    let config_path = match config_file {
+        Some(s) => canonicalize_with(&s.item, cwd).ok(),
+        None => nu_path::config_dir().map(|mut p| {
+            p.push(NUSHELL_FOLDER);
+            p.push(default_config_name);
+            p
+        }),
+    };
+
+    if let Some(path) = config_path {
+        engine_state.set_config_path(key, path);
+    }
+}

src/main.rs

@@ -1,138 +1,37 @@
+mod command;
 mod config_files;
 mod logger;
 mod signals;
+mod terminal;
 mod test_bins;
 #[cfg(test)]
 mod tests;
 
 #[cfg(feature = "plugin")]
 use crate::config_files::NUSHELL_FOLDER;
-use crate::logger::{configure, logger};
+use crate::{
+    command::parse_commandline_args,
+    config_files::{set_config_path, setup_config},
+    logger::{configure, logger},
+    terminal::acquire_terminal,
+};
 use log::{info, Level};
 use miette::Result;
 #[cfg(feature = "plugin")]
 use nu_cli::read_plugin_file;
 use nu_cli::{
     evaluate_commands, evaluate_file, evaluate_repl, gather_parent_env_vars, get_init_cwd,
-    report_error, report_error_new,
+    report_error_new,
 };
 use nu_command::create_default_context;
-use nu_engine::{get_full_help, CallExt};
+use nu_parser::{escape_for_script_arg, escape_quote_string};
-use nu_parser::{escape_for_script_arg, escape_quote_string, parse};
+use nu_protocol::{util::BufferedReader, PipelineData, RawStream};
-use nu_path::canonicalize_with;
-use nu_protocol::{
-    ast::{Call, Expr, Expression, PipelineElement},
-    engine::{Command, EngineState, Stack, StateWorkingSet},
-    util::BufferedReader,
-    Category, Example, IntoPipelineData, PipelineData, RawStream, ShellError, Signature, Spanned,
-    SyntaxShape, Value,
-};
-use nu_utils::stdout_write_all_and_flush;
 use signals::{ctrlc_protection, sigquit_protection};
+use std::str::FromStr;
 use std::{
     io::BufReader,
     sync::{atomic::AtomicBool, Arc},
 };
-use std::{path::Path, str::FromStr};
-
-// Inspired by fish's acquire_tty_or_exit
-#[cfg(unix)]
-fn take_control(interactive: bool) {
-    use nix::{
-        errno::Errno,
-        sys::signal::{self, SaFlags, SigAction, SigHandler, SigSet, Signal},
-        unistd::{self, Pid},
-    };
-
-    let shell_pgid = unistd::getpgrp();
-
-    match unistd::tcgetpgrp(nix::libc::STDIN_FILENO) {
-        Ok(owner_pgid) if owner_pgid == shell_pgid => {
-            // Common case, nothing to do
-            return;
-        }
-        Ok(owner_pgid) if owner_pgid == unistd::getpid() => {
-            // This can apparently happen with sudo: https://github.com/fish-shell/fish-shell/issues/7388
-            let _ = unistd::setpgid(owner_pgid, owner_pgid);
-            return;
-        }
-        _ => (),
-    }
-
-    // Reset all signal handlers to default
-    for sig in Signal::iterator() {
-        unsafe {
-            if let Ok(old_act) = signal::sigaction(
-                sig,
-                &SigAction::new(SigHandler::SigDfl, SaFlags::empty(), SigSet::empty()),
-            ) {
-                // fish preserves ignored SIGHUP, presumably for nohup support, so let's do the same
-                if sig == Signal::SIGHUP && old_act.handler() == SigHandler::SigIgn {
-                    let _ = signal::sigaction(sig, &old_act);
-                }
-            }
-        }
-    }
-
-    let mut success = false;
-    for _ in 0..4096 {
-        match unistd::tcgetpgrp(nix::libc::STDIN_FILENO) {
-            Ok(owner_pgid) if owner_pgid == shell_pgid => {
-                success = true;
-                break;
-            }
-            Ok(owner_pgid) if owner_pgid == Pid::from_raw(0) => {
-                // Zero basically means something like "not owned" and we can just take it
-                let _ = unistd::tcsetpgrp(nix::libc::STDIN_FILENO, shell_pgid);
-            }
-            Err(Errno::ENOTTY) => {
-                if !interactive {
-                    // that's fine
-                    return;
-                }
-                eprintln!("ERROR: no TTY for interactive shell");
-                std::process::exit(1);
-            }
-            _ => {
-                // fish also has other heuristics than "too many attempts" for the orphan check, but they're optional
-                if signal::killpg(Pid::from_raw(-shell_pgid.as_raw()), Signal::SIGTTIN).is_err() {
-                    if !interactive {
-                        // that's fine
-                        return;
-                    }
-                    eprintln!("ERROR: failed to SIGTTIN ourselves");
-                    std::process::exit(1);
-                }
-            }
-        }
-    }
-    if !success && interactive {
-        eprintln!("ERROR: failed take control of the terminal, we might be orphaned");
-        std::process::exit(1);
-    }
-}
-
-#[cfg(unix)]
-fn acquire_terminal(interactive: bool) {
-    use nix::sys::signal::{signal, SigHandler, Signal};
-
-    if !atty::is(atty::Stream::Stdin) {
-        return;
-    }
-
-    take_control(interactive);
-
-    unsafe {
-        // SIGINT and SIGQUIT have special handling above
-        signal(Signal::SIGTSTP, SigHandler::SigIgn).expect("signal ignore");
-        signal(Signal::SIGTTIN, SigHandler::SigIgn).expect("signal ignore");
-        signal(Signal::SIGTTOU, SigHandler::SigIgn).expect("signal ignore");
-        // signal::signal(Signal::SIGCHLD, SigHandler::SigIgn).expect("signal ignore"); // needed for std::command's waitpid usage
-    }
-}
-
-#[cfg(not(unix))]
-fn acquire_terminal(_: bool) {}
 
 fn main() -> Result<()> {
     let miette_hook = std::panic::take_hook();
@@ -423,343 +322,3 @@ fn main() -> Result<()> {
         ret_val
     }
 }
-
-fn setup_config(
-    engine_state: &mut EngineState,
-    stack: &mut Stack,
-    #[cfg(feature = "plugin")] plugin_file: Option<Spanned<String>>,
-    config_file: Option<Spanned<String>>,
-    env_file: Option<Spanned<String>>,
-    is_login_shell: bool,
-) {
-    #[cfg(feature = "plugin")]
-    read_plugin_file(engine_state, stack, plugin_file, NUSHELL_FOLDER);
-
-    info!("read_config_file {}:{}:{}", file!(), line!(), column!());
-
-    config_files::read_config_file(engine_state, stack, env_file, true);
-    config_files::read_config_file(engine_state, stack, config_file, false);
-
-    if is_login_shell {
-        config_files::read_loginshell_file(engine_state, stack);
-    }
-
-    // Give a warning if we see `$config` for a few releases
-    {
-        let working_set = StateWorkingSet::new(engine_state);
-        if working_set.find_variable(b"$config").is_some() {
-            println!("warning: use `let-env config = ...` instead of `let config = ...`");
-        }
-    }
-}
-
-fn parse_commandline_args(
-    commandline_args: &str,
-    engine_state: &mut EngineState,
-) -> Result<NushellCliArgs, ShellError> {
-    let (block, delta) = {
-        let mut working_set = StateWorkingSet::new(engine_state);
-        working_set.add_decl(Box::new(Nu));
-
-        let (output, err) = parse(
-            &mut working_set,
-            None,
-            commandline_args.as_bytes(),
-            false,
-            &[],
-        );
-        if let Some(err) = err {
-            report_error(&working_set, &err);
-
-            std::process::exit(1);
-        }
-
-        working_set.hide_decl(b"nu");
-        (output, working_set.render())
-    };
-
-    engine_state.merge_delta(delta)?;
-
-    let mut stack = Stack::new();
-
-    // We should have a successful parse now
-    if let Some(pipeline) = block.pipelines.get(0) {
-        if let Some(PipelineElement::Expression(
-            _,
-            Expression {
-                expr: Expr::Call(call),
-                ..
-            },
-        )) = pipeline.elements.get(0)
-        {
-            let redirect_stdin = call.get_named_arg("stdin");
-            let login_shell = call.get_named_arg("login");
-            let interactive_shell = call.get_named_arg("interactive");
-            let commands: Option<Expression> = call.get_flag_expr("commands");
-            let testbin: Option<Expression> = call.get_flag_expr("testbin");
-            #[cfg(feature = "plugin")]
-            let plugin_file: Option<Expression> = call.get_flag_expr("plugin-config");
-            let config_file: Option<Expression> = call.get_flag_expr("config");
-            let env_file: Option<Expression> = call.get_flag_expr("env-config");
-            let log_level: Option<Expression> = call.get_flag_expr("log-level");
-            let log_target: Option<Expression> = call.get_flag_expr("log-target");
-            let execute: Option<Expression> = call.get_flag_expr("execute");
-            let threads: Option<Value> = call.get_flag(engine_state, &mut stack, "threads")?;
-            let table_mode: Option<Value> =
-                call.get_flag(engine_state, &mut stack, "table-mode")?;
-
-            fn extract_contents(
-                expression: Option<Expression>,
-            ) -> Result<Option<Spanned<String>>, ShellError> {
-                if let Some(expr) = expression {
-                    let str = expr.as_string();
-                    if let Some(str) = str {
-                        Ok(Some(Spanned {
-                            item: str,
-                            span: expr.span,
-                        }))
-                    } else {
-                        Err(ShellError::TypeMismatch("string".into(), expr.span))
-                    }
-                } else {
-                    Ok(None)
-                }
-            }
-
-            let commands = extract_contents(commands)?;
-            let testbin = extract_contents(testbin)?;
-            #[cfg(feature = "plugin")]
-            let plugin_file = extract_contents(plugin_file)?;
-            let config_file = extract_contents(config_file)?;
-            let env_file = extract_contents(env_file)?;
-            let log_level = extract_contents(log_level)?;
-            let log_target = extract_contents(log_target)?;
-            let execute = extract_contents(execute)?;
-
-            let help = call.has_flag("help");
-
-            if help {
-                let full_help = get_full_help(
-                    &Nu.signature(),
-                    &Nu.examples(),
-                    engine_state,
-                    &mut stack,
-                    true,
-                );
-
-                let _ = std::panic::catch_unwind(move || stdout_write_all_and_flush(full_help));
-
-                std::process::exit(1);
-            }
-
-            if call.has_flag("version") {
-                let version = env!("CARGO_PKG_VERSION").to_string();
-                let _ = std::panic::catch_unwind(move || {
-                    stdout_write_all_and_flush(format!("{}\n", version))
-                });
-
-                std::process::exit(0);
-            }
-
-            return Ok(NushellCliArgs {
-                redirect_stdin,
-                login_shell,
-                interactive_shell,
-                commands,
-                testbin,
-                #[cfg(feature = "plugin")]
-                plugin_file,
-                config_file,
-                env_file,
-                log_level,
-                log_target,
-                execute,
-                threads,
-                table_mode,
-            });
-        }
-    }
-
-    // Just give the help and exit if the above fails
-    let full_help = get_full_help(
-        &Nu.signature(),
-        &Nu.examples(),
-        engine_state,
-        &mut stack,
-        true,
-    );
-    print!("{}", full_help);
-    std::process::exit(1);
-}
-
-struct NushellCliArgs {
-    redirect_stdin: Option<Spanned<String>>,
-    login_shell: Option<Spanned<String>>,
-    interactive_shell: Option<Spanned<String>>,
-    commands: Option<Spanned<String>>,
-    testbin: Option<Spanned<String>>,
-    #[cfg(feature = "plugin")]
-    plugin_file: Option<Spanned<String>>,
-    config_file: Option<Spanned<String>>,
-    env_file: Option<Spanned<String>>,
-    log_level: Option<Spanned<String>>,
-    log_target: Option<Spanned<String>>,
-    execute: Option<Spanned<String>>,
-    threads: Option<Value>,
-    table_mode: Option<Value>,
-}
-
-#[derive(Clone)]
-struct Nu;
-
-impl Command for Nu {
-    fn name(&self) -> &str {
-        "nu"
-    }
-
-    fn signature(&self) -> Signature {
-        let mut signature = Signature::build("nu")
-            .usage("The nushell language and shell.")
-            .named(
-                "commands",
-                SyntaxShape::String,
-                "run the given commands and then exit",
-                Some('c'),
-            )
-            .named(
-                "execute",
-                SyntaxShape::String,
-                "run the given commands and then enter an interactive shell",
-                Some('e'),
-            )
-            .switch("interactive", "start as an interactive shell", Some('i'))
-            .switch("login", "start as a login shell", Some('l'))
-            .named(
-                "table-mode",
-                SyntaxShape::String,
-                "the table mode to use. rounded is default.",
-                Some('m'),
-            )
-            .named(
-                "threads",
-                SyntaxShape::Int,
-                "threads to use for parallel commands",
-                Some('t'),
-            )
-            .switch("version", "print the version", Some('v'))
-            .named(
-                "config",
-                SyntaxShape::String,
-                "start with an alternate config file",
-                None,
-            )
-            .named(
-                "env-config",
-                SyntaxShape::String,
-                "start with an alternate environment config file",
-                None,
-            );
-
-        #[cfg(feature = "plugin")]
-        {
-            signature = signature.named(
-                "plugin-config",
-                SyntaxShape::String,
-                "start with an alternate plugin signature file",
-                None,
-            );
-        }
-
-        signature = signature
-            .named(
-                "log-level",
-                SyntaxShape::String,
-                "log level for diagnostic logs (error, warn, info, debug, trace). Off by default",
-                None,
-            )
-            .named(
-                "log-target",
-                SyntaxShape::String,
-                "set the target for the log to output. stdout, stderr(default), mixed or file",
-                None,
-            )
-            .switch(
-                "stdin",
-                "redirect standard input to a command (with `-c`) or a script file",
-                None,
-            )
-            .named(
-                "testbin",
-                SyntaxShape::String,
-                "run internal test binary",
-                None,
-            )
-            .optional(
-                "script file",
-                SyntaxShape::Filepath,
-                "name of the optional script file to run",
-            )
-            .rest(
-                "script args",
-                SyntaxShape::String,
-                "parameters to the script file",
-            )
-            .category(Category::System);
-
-        signature
-    }
-
-    fn usage(&self) -> &str {
-        "The nushell language and shell."
-    }
-
-    fn run(
-        &self,
-        engine_state: &EngineState,
-        stack: &mut Stack,
-        call: &Call,
-        _input: PipelineData,
-    ) -> Result<nu_protocol::PipelineData, nu_protocol::ShellError> {
-        Ok(Value::String {
-            val: get_full_help(&Nu.signature(), &Nu.examples(), engine_state, stack, true),
-            span: call.head,
-        }
-        .into_pipeline_data())
-    }
-
-    fn examples(&self) -> Vec<nu_protocol::Example> {
-        vec![
-            Example {
-                description: "Run a script",
-                example: "nu myfile.nu",
-                result: None,
-            },
-            Example {
-                description: "Run nushell interactively (as a shell or REPL)",
-                example: "nu",
-                result: None,
-            },
-        ]
-    }
-}
-
-fn set_config_path(
-    engine_state: &mut EngineState,
-    cwd: &Path,
-    default_config_name: &str,
-    key: &str,
-    config_file: &Option<Spanned<String>>,
-) {
-    let config_path = match config_file {
-        Some(s) => canonicalize_with(&s.item, cwd).ok(),
-        None => nu_path::config_dir().map(|mut p| {
-            p.push(config_files::NUSHELL_FOLDER);
-            p.push(default_config_name);
-            p
-        }),
-    };
-
-    if let Some(path) = config_path {
-        engine_state.set_config_path(key, path);
-    }
-}

src/terminal.rs

@@ -0,0 +1,97 @@
+#[cfg(unix)]
+pub(crate) fn acquire_terminal(interactive: bool) {
+    use nix::sys::signal::{signal, SigHandler, Signal};
+
+    if !atty::is(atty::Stream::Stdin) {
+        return;
+    }
+
+    take_control(interactive);
+
+    unsafe {
+        // SIGINT and SIGQUIT have special handling above
+        signal(Signal::SIGTSTP, SigHandler::SigIgn).expect("signal ignore");
+        signal(Signal::SIGTTIN, SigHandler::SigIgn).expect("signal ignore");
+        signal(Signal::SIGTTOU, SigHandler::SigIgn).expect("signal ignore");
+    }
+}
+
+#[cfg(not(unix))]
+pub(crate) fn acquire_terminal(_: bool) {}
+
+// Inspired by fish's acquire_tty_or_exit
+#[cfg(unix)]
+fn take_control(interactive: bool) {
+    use nix::{
+        errno::Errno,
+        sys::signal::{self, SaFlags, SigAction, SigHandler, SigSet, Signal},
+        unistd::{self, Pid},
+    };
+
+    let shell_pgid = unistd::getpgrp();
+
+    match unistd::tcgetpgrp(nix::libc::STDIN_FILENO) {
+        Ok(owner_pgid) if owner_pgid == shell_pgid => {
+            // Common case, nothing to do
+            return;
+        }
+        Ok(owner_pgid) if owner_pgid == unistd::getpid() => {
+            // This can apparently happen with sudo: https://github.com/fish-shell/fish-shell/issues/7388
+            let _ = unistd::setpgid(owner_pgid, owner_pgid);
+            return;
+        }
+        _ => (),
+    }
+
+    // Reset all signal handlers to default
+    for sig in Signal::iterator() {
+        unsafe {
+            if let Ok(old_act) = signal::sigaction(
+                sig,
+                &SigAction::new(SigHandler::SigDfl, SaFlags::empty(), SigSet::empty()),
+            ) {
+                // fish preserves ignored SIGHUP, presumably for nohup support, so let's do the same
+                if sig == Signal::SIGHUP && old_act.handler() == SigHandler::SigIgn {
+                    let _ = signal::sigaction(sig, &old_act);
+                }
+            }
+        }
+    }
+
+    let mut success = false;
+    for _ in 0..4096 {
+        match unistd::tcgetpgrp(nix::libc::STDIN_FILENO) {
+            Ok(owner_pgid) if owner_pgid == shell_pgid => {
+                success = true;
+                break;
+            }
+            Ok(owner_pgid) if owner_pgid == Pid::from_raw(0) => {
+                // Zero basically means something like "not owned" and we can just take it
+                let _ = unistd::tcsetpgrp(nix::libc::STDIN_FILENO, shell_pgid);
+            }
+            Err(Errno::ENOTTY) => {
+                if !interactive {
+                    // that's fine
+                    return;
+                }
+                eprintln!("ERROR: no TTY for interactive shell");
+                std::process::exit(1);
+            }
+            _ => {
+                // fish also has other heuristics than "too many attempts" for the orphan check, but they're optional
+                if signal::killpg(Pid::from_raw(-shell_pgid.as_raw()), Signal::SIGTTIN).is_err() {
+                    if !interactive {
+                        // that's fine
+                        return;
+                    }
+                    eprintln!("ERROR: failed to SIGTTIN ourselves");
+                    std::process::exit(1);
+                }
+            }
+        }
+    }
+    if !success && interactive {
+        eprintln!("ERROR: failed take control of the terminal, we might be orphaned");
+        std::process::exit(1);
+    }
+}