Files
shed/src/parse/execute.rs

1402 lines
41 KiB
Rust

use std::{
cell::Cell,
collections::{HashSet, VecDeque},
os::unix::fs::PermissionsExt,
};
use ariadne::Fmt;
use crate::{
builtin::{
alias::{alias, unalias}, arrops::{arr_fpop, arr_fpush, arr_pop, arr_push, arr_rotate}, autocmd::autocmd, cd::cd, complete::{compgen_builtin, complete_builtin}, dirstack::{dirs, popd, pushd}, echo::echo, eval, exec, flowctl::flowctl, getopts::getopts, intro, jobctl::{self, JobBehavior, continue_job, disown, jobs}, keymap, map, pwd::pwd, read::{self, read_builtin}, resource::{ulimit, umask_builtin}, shift::shift, shopt::shopt, source::source, test::double_bracket_test, trap::{TrapTarget, trap}, varcmds::{export, local, readonly, unset}
},
expand::{expand_aliases, expand_case_pattern, glob_to_regex},
jobs::{ChildProc, JobStack, attach_tty, dispatch_job},
libsh::{
error::{ShErr, ShErrKind, ShResult, ShResultExt, next_color},
guards::{scope_guard, var_ctx_guard},
utils::RedirVecUtils,
},
prelude::*,
procio::{IoMode, IoStack, PipeGenerator},
state::{
self, ShFunc, VarFlags, VarKind, read_logic, read_shopts, write_jobs, write_logic, write_vars,
},
};
use super::{
AssignKind, CaseNode, CondNode, ConjunctNode, ConjunctOp, LoopKind, NdFlags, NdRule, Node,
ParsedSrc, Redir, RedirType,
lex::{KEYWORDS, Span, Tk, TkFlags},
};
thread_local! {
static RECURSE_DEPTH: Cell<usize> = const { Cell::new(0) };
}
pub fn is_in_path(name: &str) -> bool {
if name.starts_with("./") || name.starts_with("../") || name.starts_with('/') {
let path = Path::new(name);
if path.exists() && path.is_file() && !path.is_dir() {
let meta = match path.metadata() {
Ok(m) => m,
Err(_) => return false,
};
if meta.permissions().mode() & 0o111 != 0 {
return true;
}
}
false
} else {
let Ok(path) = env::var("PATH") else {
return false;
};
let paths = path.split(':');
for path in paths {
let full_path = Path::new(path).join(name);
if full_path.exists() && full_path.is_file() && !full_path.is_dir() {
let meta = match full_path.metadata() {
Ok(m) => m,
Err(_) => continue,
};
if meta.permissions().mode() & 0o111 != 0 {
return true;
}
}
}
false
}
}
pub enum AssignBehavior {
Export,
Set,
}
/// Arguments to the execvpe function
pub struct ExecArgs {
pub cmd: (CString, Span),
pub argv: Vec<CString>,
pub envp: Vec<CString>,
}
impl ExecArgs {
pub fn new(argv: Vec<Tk>) -> ShResult<Self> {
assert!(!argv.is_empty());
let argv = prepare_argv(argv)?;
Self::from_expanded(argv)
}
pub fn from_expanded(argv: Vec<(String, Span)>) -> ShResult<Self> {
assert!(!argv.is_empty());
let cmd = Self::get_cmd(&argv);
let argv = Self::get_argv(argv);
let envp = Self::get_envp();
Ok(Self { cmd, argv, envp })
}
pub fn get_cmd(argv: &[(String, Span)]) -> (CString, Span) {
let cmd = argv[0].0.as_str();
let span = argv[0].1.clone();
(CString::new(cmd).unwrap(), span)
}
pub fn get_argv(argv: Vec<(String, Span)>) -> Vec<CString> {
argv
.into_iter()
.map(|s| CString::new(s.0).unwrap())
.collect()
}
pub fn get_envp() -> Vec<CString> {
std::env::vars()
.map(|v| CString::new(format!("{}={}", v.0, v.1)).unwrap())
.collect()
}
}
/// Execute a `-c` command string, optimizing single simple commands to exec
/// directly without forking. This avoids process group issues where grandchild
/// processes (e.g. nvim spawning opencode) lose their controlling terminal.
pub fn exec_dash_c(input: String) -> ShResult<()> {
let log_tab = read_logic(|l| l.clone());
let expanded = expand_aliases(input, HashSet::new(), &log_tab);
let source_name = "<shed -c>".to_string();
let mut parser = ParsedSrc::new(Arc::new(expanded))
.with_lex_flags(super::lex::LexFlags::empty())
.with_name(source_name.clone());
if let Err(errors) = parser.parse_src() {
for error in errors {
error.print_error();
}
return Ok(());
}
let mut nodes = parser.extract_nodes();
// Single simple command: exec directly without forking.
// The parser wraps single commands as Conjunction → Pipeline → Command.
// Unwrap all layers to check, then set NO_FORK on the inner Command.
if nodes.len() == 1 {
let is_single_cmd = match &nodes[0].class {
NdRule::Command { .. } => true,
NdRule::Pipeline { cmds } => cmds.len() == 1 && matches!(cmds[0].class, NdRule::Command { .. }),
NdRule::Conjunction { elements } => {
elements.len() == 1 && match &elements[0].cmd.class {
NdRule::Pipeline { cmds } => cmds.len() == 1 && matches!(cmds[0].class, NdRule::Command { .. }),
NdRule::Command { .. } => true,
_ => false,
}
}
_ => false,
};
if is_single_cmd {
// Unwrap to the inner Command node
let mut node = nodes.remove(0);
loop {
match node.class {
NdRule::Conjunction { mut elements } => { node = *elements.remove(0).cmd; }
NdRule::Pipeline { mut cmds } => { node = cmds.remove(0); }
NdRule::Command { .. } => break,
_ => break,
}
}
node.flags |= NdFlags::NO_FORK;
nodes.push(node);
}
}
let mut dispatcher = Dispatcher::new(nodes, false, source_name);
// exec_cmd expects a job on the stack (normally set up by exec_pipeline).
// For the NO_FORK exec-in-place path, create one so it doesn't panic.
dispatcher.job_stack.new_job();
dispatcher.begin_dispatch()
}
pub fn exec_input(
input: String,
io_stack: Option<IoStack>,
interactive: bool,
source_name: Option<String>,
) -> ShResult<()> {
let log_tab = read_logic(|l| l.clone());
let input = expand_aliases(input, HashSet::new(), &log_tab);
let lex_flags = if interactive {
super::lex::LexFlags::INTERACTIVE
} else {
super::lex::LexFlags::empty()
};
let source_name = source_name.unwrap_or("<stdin>".into());
let mut parser = ParsedSrc::new(Arc::new(input))
.with_lex_flags(lex_flags)
.with_name(source_name.clone());
if let Err(errors) = parser.parse_src() {
for error in errors {
error.print_error();
}
return Ok(());
}
let nodes = parser.extract_nodes();
let mut dispatcher = Dispatcher::new(nodes, interactive, source_name.clone());
if let Some(mut stack) = io_stack {
dispatcher.io_stack.extend(stack.drain(..));
}
let result = dispatcher.begin_dispatch();
if state::get_status() != 0
&& let Some(trap) = read_logic(|l| l.get_trap(TrapTarget::Error))
{
let saved_status = state::get_status();
exec_input(trap, None, false, Some(source_name))?;
state::set_status(saved_status);
}
result
}
pub struct Dispatcher {
nodes: VecDeque<Node>,
interactive: bool,
source_name: String,
pub io_stack: IoStack,
pub job_stack: JobStack,
fg_job: bool,
}
impl Dispatcher {
pub fn new(nodes: Vec<Node>, interactive: bool, source_name: String) -> Self {
let nodes = VecDeque::from(nodes);
Self {
nodes,
interactive,
source_name,
io_stack: IoStack::new(),
job_stack: JobStack::new(),
fg_job: true,
}
}
pub fn begin_dispatch(&mut self) -> ShResult<()> {
while let Some(node) = self.nodes.pop_front() {
let blame = node.get_span();
self.dispatch_node(node).try_blame(blame)?;
}
Ok(())
}
pub fn dispatch_node(&mut self, node: Node) -> ShResult<()> {
match node.class {
NdRule::Conjunction { .. } => self.exec_conjunction(node)?,
NdRule::Pipeline { .. } => self.exec_pipeline(node)?,
NdRule::IfNode { .. } => self.exec_if(node)?,
NdRule::LoopNode { .. } => self.exec_loop(node)?,
NdRule::ForNode { .. } => self.exec_for(node)?,
NdRule::CaseNode { .. } => self.exec_case(node)?,
NdRule::BraceGrp { .. } => self.exec_brc_grp(node)?,
NdRule::FuncDef { .. } => self.exec_func_def(node)?,
NdRule::Negate { .. } => self.exec_negated(node)?,
NdRule::Command { .. } => self.dispatch_cmd(node)?,
NdRule::Test { .. } => self.exec_test(node)?,
_ => unreachable!(),
}
Ok(())
}
pub fn dispatch_cmd(&mut self, node: Node) -> ShResult<()> {
let Some(cmd) = node.get_command() else {
return self.exec_cmd(node); // Argv is empty, probably an assignment
};
if is_func(node.get_command().cloned()) {
self.exec_func(node)
} else if cmd.flags.contains(TkFlags::BUILTIN) {
self.exec_builtin(node)
} else if is_subsh(node.get_command().cloned()) {
self.exec_subsh(node)
} else if read_shopts(|s| s.core.autocd)
&& Path::new(cmd.span.as_str()).is_dir()
&& !is_in_path(cmd.span.as_str())
{
let dir = cmd.span.as_str().to_string();
let stack = IoStack {
stack: self.io_stack.clone(),
};
exec_input(
format!("cd {dir}"),
Some(stack),
self.interactive,
Some(self.source_name.clone()),
)
} else {
self.exec_cmd(node)
}
}
pub fn exec_negated(&mut self, node: Node) -> ShResult<()> {
let NdRule::Negate { cmd } = node.class else {
unreachable!()
};
self.dispatch_node(*cmd)?;
let status = state::get_status();
state::set_status(if status == 0 { 1 } else { 0 });
Ok(())
}
pub fn exec_conjunction(&mut self, conjunction: Node) -> ShResult<()> {
let NdRule::Conjunction { elements } = conjunction.class else {
unreachable!()
};
let mut elem_iter = elements.into_iter();
while let Some(element) = elem_iter.next() {
let ConjunctNode { cmd, operator } = element;
self.dispatch_node(*cmd)?;
let status = state::get_status();
match operator {
ConjunctOp::And => {
if status != 0 {
break;
}
}
ConjunctOp::Or => {
if status == 0 {
break;
}
}
ConjunctOp::Null => break,
}
}
Ok(())
}
pub fn exec_test(&mut self, node: Node) -> ShResult<()> {
let test_result = double_bracket_test(node)?;
match test_result {
true => state::set_status(0),
false => state::set_status(1),
}
Ok(())
}
pub fn exec_func_def(&mut self, func_def: Node) -> ShResult<()> {
let blame = func_def.get_span();
let ctx = func_def.context.clone();
let NdRule::FuncDef { name, body } = func_def.class else {
unreachable!()
};
let body_span = body.get_span();
let body = body_span.as_str().to_string();
let name = name.span.as_str().strip_suffix("()").unwrap();
if KEYWORDS.contains(&name) {
return Err(ShErr::at(
ShErrKind::SyntaxErr,
blame,
format!("function: Forbidden function name `{name}`"),
));
}
let mut func_parser = ParsedSrc::new(Arc::new(body)).with_context(ctx);
if let Err(errors) = func_parser.parse_src() {
for error in errors {
error.print_error();
}
return Ok(());
}
let func = ShFunc::new(func_parser, blame);
write_logic(|l| l.insert_func(name, func)); // Store the AST
Ok(())
}
fn exec_subsh(&mut self, subsh: Node) -> ShResult<()> {
let _blame = subsh.get_span().clone();
let NdRule::Command { assignments, argv } = subsh.class else {
unreachable!()
};
let name = self.source_name.clone();
self.io_stack.append_to_frame(subsh.redirs);
let _guard = self.io_stack.pop_frame().redirect()?;
self.run_fork("anonymous_subshell", |s| {
if let Err(e) = s.set_assignments(assignments, AssignBehavior::Export) {
e.print_error();
return;
};
let subsh_raw = argv[0].span.as_str();
let subsh_body = subsh_raw[1..subsh_raw.len() - 1].to_string(); // Remove surrounding parentheses
if let Err(e) = exec_input(subsh_body, None, s.interactive, Some(name)) {
e.print_error();
};
})
}
fn exec_func(&mut self, func: Node) -> ShResult<()> {
let mut blame = func.get_span().clone();
let func_name = func.get_command().unwrap().to_string();
let func_ctx = func.get_context(format!(
"in call to function '{}'",
func_name.fg(next_color())
));
let NdRule::Command {
assignments,
mut argv,
} = func.class
else {
unreachable!()
};
let max_depth = read_shopts(|s| s.core.max_recurse_depth);
let depth = RECURSE_DEPTH.with(|d| {
let cur = d.get();
d.set(cur + 1);
cur + 1
});
if depth > max_depth {
RECURSE_DEPTH.with(|d| d.set(d.get() - 1));
return Err(ShErr::at(
ShErrKind::InternalErr,
blame,
format!("maximum recursion depth ({max_depth}) exceeded"),
));
}
let env_vars = self.set_assignments(assignments, AssignBehavior::Export)?;
let func_name = argv.remove(0).to_string();
let _var_guard = var_ctx_guard(env_vars.into_iter().collect());
self.io_stack.append_to_frame(func.redirs);
blame.rename(func_name.clone());
let mut argv = prepare_argv(argv).try_blame(blame.clone())?;
argv.insert(0, (func_name.clone(), blame.clone()));
let result = if let Some(ref mut func_body) = read_logic(|l| l.get_func(&func_name)) {
let _guard = scope_guard(Some(argv));
func_body.body_mut().propagate_context(func_ctx);
func_body.body_mut().flags = func.flags;
if let Err(e) = self.exec_pipeline(func_body.body().clone()) {
match e.kind() {
ShErrKind::FuncReturn(code) => {
state::set_status(*code);
Ok(())
}
_ => Err(e),
}
} else {
Ok(())
}
} else {
Err(ShErr::at(
ShErrKind::InternalErr,
blame,
format!("Failed to find function '{}'", func_name),
))
};
RECURSE_DEPTH.with(|d| d.set(d.get() - 1));
result
}
fn exec_brc_grp(&mut self, brc_grp: Node) -> ShResult<()> {
let NdRule::BraceGrp { body } = brc_grp.class else {
unreachable!("expected BraceGrp node, got {:?}", brc_grp.class)
};
if self.interactive {
log::debug!("Executing brace group, body: {:?}", body);
}
let fork_builtins = brc_grp.flags.contains(NdFlags::FORK_BUILTINS);
self.io_stack.append_to_frame(brc_grp.redirs);
let guard = self.io_stack.pop_frame().redirect()?;
let brc_grp_logic = |s: &mut Self| -> ShResult<()> {
for node in body {
let blame = node.get_span();
s.dispatch_node(node).try_blame(blame)?;
}
Ok(())
};
if fork_builtins {
log::trace!("Forking brace group");
self.run_fork("brace group", |s| {
if let Err(e) = brc_grp_logic(s) {
e.print_error();
}
})
} else {
brc_grp_logic(self).map_err(|e| e.with_redirs(guard))
}
}
fn exec_case(&mut self, case_stmt: Node) -> ShResult<()> {
let blame = case_stmt.get_span().clone();
let NdRule::CaseNode {
pattern,
case_blocks,
} = case_stmt.class
else {
unreachable!()
};
let fork_builtins = case_stmt.flags.contains(NdFlags::FORK_BUILTINS);
self.io_stack.append_to_frame(case_stmt.redirs);
let guard = self.io_stack.pop_frame().redirect()?;
let case_logic = |s: &mut Self| -> ShResult<()> {
let exp_pattern = pattern.clone().expand()?;
let pattern_raw = exp_pattern
.get_words()
.first()
.map(|s| s.to_string())
.unwrap_or_default();
'outer: for block in case_blocks {
let CaseNode { pattern, body } = block;
let block_pattern_raw = pattern
.span
.as_str()
.strip_suffix(')')
.unwrap_or(pattern.span.as_str())
.trim();
// Split at '|' to allow for multiple patterns like `foo|bar)`
let block_patterns = block_pattern_raw.split('|');
for pattern in block_patterns {
let pattern_exp = expand_case_pattern(pattern)?;
let pattern_regex = glob_to_regex(&pattern_exp, false);
if pattern_regex.is_match(&pattern_raw) {
for node in &body {
s.dispatch_node(node.clone())?;
}
break 'outer;
}
}
}
Ok(())
};
if fork_builtins {
log::trace!("Forking builtin: case");
self.run_fork("case", |s| {
if let Err(e) = case_logic(s) {
e.print_error();
}
})
} else {
case_logic(self)
.try_blame(blame)
.map_err(|e| e.with_redirs(guard))
}
}
fn exec_loop(&mut self, loop_stmt: Node) -> ShResult<()> {
let blame = loop_stmt.get_span().clone();
let NdRule::LoopNode { kind, cond_node } = loop_stmt.class else {
unreachable!();
};
let keep_going = |kind: LoopKind, status: i32| -> bool {
match kind {
LoopKind::While => status == 0,
LoopKind::Until => status != 0,
}
};
let fork_builtins = loop_stmt.flags.contains(NdFlags::FORK_BUILTINS);
self.io_stack.append_to_frame(loop_stmt.redirs);
let guard = self.io_stack.pop_frame().redirect()?;
let loop_logic = |s: &mut Self| -> ShResult<()> {
let CondNode { cond, body } = cond_node;
'outer: loop {
if let Err(e) = s.dispatch_node(*cond.clone()) {
state::set_status(1);
return Err(e);
}
let status = state::get_status();
if keep_going(kind, status) {
for node in &body {
if let Err(e) = s.dispatch_node(node.clone()) {
match e.kind() {
ShErrKind::LoopBreak(code) => {
state::set_status(*code);
break 'outer;
}
ShErrKind::LoopContinue(code) => {
state::set_status(*code);
continue 'outer;
}
_ => {
return Err(e);
}
}
}
}
} else {
state::set_status(0);
break;
}
}
Ok(())
};
if fork_builtins {
log::trace!("Forking builtin: loop");
self.run_fork("loop", |s| {
if let Err(e) = loop_logic(s) {
e.print_error();
}
})
} else {
loop_logic(self)
.try_blame(blame)
.map_err(|e| e.with_redirs(guard))
}
}
fn exec_for(&mut self, for_stmt: Node) -> ShResult<()> {
let blame = for_stmt.get_span().clone();
let NdRule::ForNode { vars, arr, body } = for_stmt.class else {
unreachable!();
};
let fork_builtins = for_stmt.flags.contains(NdFlags::FORK_BUILTINS);
let to_expanded_strings = |tks: Vec<Tk>| -> ShResult<Vec<String>> {
Ok(
tks
.into_iter()
.map(|tk| tk.expand().map(|tk| tk.get_words()))
.collect::<ShResult<Vec<Vec<String>>>>()?
.into_iter()
.flatten()
.collect::<Vec<_>>(),
)
};
self.io_stack.append_to_frame(for_stmt.redirs);
let guard = self.io_stack.pop_frame().redirect()?;
let for_logic = |s: &mut Self| -> ShResult<()> {
// Expand all array variables
let arr: Vec<String> = to_expanded_strings(arr)?;
let vars: Vec<String> = to_expanded_strings(vars)?;
let mut for_guard = var_ctx_guard(vars.iter().map(|v| v.to_string()).collect());
'outer: for chunk in arr.chunks(vars.len()) {
let empty = String::new();
let chunk_iter = vars
.iter()
.zip(chunk.iter().chain(std::iter::repeat(&empty)));
for (var, val) in chunk_iter {
write_vars(|v| {
v.set_var(
&var.to_string(),
VarKind::Str(val.to_string()),
VarFlags::NONE,
)
})?;
for_guard.insert(var.to_string());
}
for node in body.clone() {
if let Err(e) = s.dispatch_node(node) {
match e.kind() {
ShErrKind::LoopBreak(code) => {
state::set_status(*code);
break 'outer;
}
ShErrKind::LoopContinue(code) => {
state::set_status(*code);
continue 'outer;
}
_ => return Err(e),
}
}
}
}
Ok(())
};
if fork_builtins {
log::trace!("Forking builtin: for");
self.run_fork("for", |s| {
if let Err(e) = for_logic(s) {
e.print_error();
}
})
} else {
for_logic(self)
.try_blame(blame)
.map_err(|e| e.with_redirs(guard))
}
}
fn exec_if(&mut self, if_stmt: Node) -> ShResult<()> {
let blame = if_stmt.get_span().clone();
let NdRule::IfNode {
cond_nodes,
else_block,
} = if_stmt.class
else {
unreachable!();
};
let fork_builtins = if_stmt.flags.contains(NdFlags::FORK_BUILTINS);
self.io_stack.append_to_frame(if_stmt.redirs);
let guard = self.io_stack.pop_frame().redirect()?;
let if_logic = |s: &mut Self| -> ShResult<()> {
let mut matched = false;
for node in cond_nodes {
let CondNode { cond, body } = node;
if let Err(e) = s.dispatch_node(*cond) {
state::set_status(1);
return Err(e);
}
match state::get_status() {
0 => {
matched = true;
for body_node in body {
s.dispatch_node(body_node)?;
}
break; // Don't check remaining elif conditions
}
_ => continue,
}
}
if !matched {
if !else_block.is_empty() {
for node in else_block {
s.dispatch_node(node)?;
}
} else {
state::set_status(0);
}
}
Ok(())
};
if fork_builtins {
log::trace!("Forking builtin: if");
self.run_fork("if", |s| {
if let Err(e) = if_logic(s) {
e.print_error();
state::set_status(1);
}
})
} else {
if_logic(self)
.try_blame(blame)
.map_err(|e| e.with_redirs(guard))
}
}
fn exec_pipeline(&mut self, pipeline: Node) -> ShResult<()> {
let NdRule::Pipeline { cmds } = pipeline.class else {
unreachable!()
};
if self.interactive {
log::debug!("Executing pipeline, cmds: {:#?}", cmds);
}
let is_bg = pipeline.flags.contains(NdFlags::BACKGROUND);
self.job_stack.new_job();
if cmds.len() == 1 {
self.fg_job = !is_bg && self.interactive;
let cmd = cmds.into_iter().next().unwrap();
self.dispatch_node(cmd)?;
// Give the pipeline terminal control as soon as the first child
// establishes the PGID, so later children (e.g. nvim) don't get
// SIGTTOU when they try to modify terminal attributes.
// Only for interactive (top-level) pipelines — command substitution
// and other non-interactive contexts must not steal the terminal.
if !is_bg
&& self.interactive
&& let Some(pgid) = self.job_stack.curr_job_mut().unwrap().pgid()
{
attach_tty(pgid).ok();
}
} else {
let (mut in_redirs, mut out_redirs) = self.io_stack.pop_frame().redirs.split_by_channel();
let mut pipes = PipeGenerator::new(cmds.len()).as_io_frames();
self.fg_job = !is_bg && self.interactive;
let mut tty_attached = false;
let last_cmd = cmds.len() - 1;
for (i, mut cmd) in cmds.into_iter().enumerate() {
let mut frame = pipes.next().ok_or_else(|| {
ShErr::at(
ShErrKind::InternalErr,
cmd.get_span(),
"failed to set up pipeline redirections".to_string(),
)
})?;
if i == 0 {
for redir in std::mem::take(&mut in_redirs) {
frame.push(redir);
}
} else if i == last_cmd {
for redir in std::mem::take(&mut out_redirs) {
frame.push(redir);
}
}
let _guard = frame.redirect()?;
cmd.flags |= NdFlags::FORK_BUILTINS; // multiple cmds means builtins must fork
self.dispatch_node(cmd)?;
// Give the pipeline terminal control as soon as the first child
// establishes the PGID, so later children (e.g. nvim) don't get
// SIGTTOU when they try to modify terminal attributes.
// Only for interactive (top-level) pipelines — command substitution
// and other non-interactive contexts must not steal the terminal.
if !tty_attached
&& !is_bg
&& self.interactive
&& let Some(pgid) = self.job_stack.curr_job_mut().unwrap().pgid()
{
attach_tty(pgid).ok();
tty_attached = true;
}
}
}
let job = self.job_stack.finalize_job().unwrap();
dispatch_job(job, is_bg, self.interactive)?;
Ok(())
}
fn exec_builtin(&mut self, cmd: Node) -> ShResult<()> {
let fork_builtins = cmd.flags.contains(NdFlags::FORK_BUILTINS);
let cmd_raw = cmd
.get_command()
.unwrap_or_else(|| panic!("expected command NdRule, got {:?}", &cmd.class))
.to_string();
if fork_builtins {
log::trace!("Forking builtin: {}", cmd_raw);
let _guard = self.io_stack.pop_frame().redirect()?;
self.run_fork(&cmd_raw, |s| {
if let Err(e) = s.dispatch_builtin(cmd) {
e.print_error();
}
})
} else {
let result = self.dispatch_builtin(cmd);
if let Err(e) = result {
let code = state::get_status();
if code == 0 {
state::set_status(1);
}
return Err(e);
}
Ok(())
}
}
fn dispatch_builtin(&mut self, mut cmd: Node) -> ShResult<()> {
let cmd_raw = cmd.get_command().unwrap().to_string();
let context = cmd.context.clone();
let NdRule::Command { assignments, argv } = &mut cmd.class else {
unreachable!()
};
let env_vars = self.set_assignments(mem::take(assignments), AssignBehavior::Export)?;
let _var_guard = var_ctx_guard(env_vars.into_iter().collect());
// Handle builtin/command recursion before redirect/job setup
if cmd_raw.as_str() == "builtin" {
*argv = argv
.iter_mut()
.skip(1)
.map(|tk| tk.clone())
.collect::<Vec<Tk>>();
return self.exec_builtin(cmd);
} else if cmd_raw.as_str() == "command" {
*argv = argv
.iter_mut()
.skip(1)
.map(|tk| tk.clone())
.collect::<Vec<Tk>>();
if cmd.flags.contains(NdFlags::FORK_BUILTINS) {
cmd.flags |= NdFlags::NO_FORK;
}
return self.exec_cmd(cmd);
}
// Set up redirections here so we can attach the guard to propagated errors.
self.io_stack.append_to_frame(mem::take(&mut cmd.redirs));
let frame = self.io_stack.pop_frame();
if self.interactive {
log::debug!(
"popped frame for builtin '{}', frame: {:#?}",
cmd_raw,
frame
);
}
let redir_guard = frame.redirect()?;
// Register ChildProc in current job
let job = self.job_stack.curr_job_mut().unwrap();
let child_pgid = if let Some(pgid) = job.pgid() {
pgid
} else {
job.set_pgid(Pid::this());
Pid::this()
};
let child = ChildProc::new(Pid::this(), Some(&cmd_raw), Some(child_pgid))?;
job.push_child(child);
// Handle exec specially — persist redirections before dispatch
if cmd_raw.as_str() == "exec" {
redir_guard.persist();
let result = exec::exec_builtin(cmd);
return if let Err(e) = result {
Err(e.with_context(context))
} else {
Ok(())
};
}
let result = match cmd_raw.as_str() {
"echo" => echo(cmd),
"cd" => cd(cmd),
"export" => export(cmd),
"local" => local(cmd),
"pwd" => pwd(cmd),
"source" | "." => source(cmd),
"shift" => shift(cmd),
"fg" => continue_job(cmd, JobBehavior::Foregound),
"bg" => continue_job(cmd, JobBehavior::Background),
"disown" => disown(cmd),
"jobs" => jobs(cmd),
"alias" => alias(cmd),
"unalias" => unalias(cmd),
"return" => flowctl(cmd, ShErrKind::FuncReturn(0)),
"break" => flowctl(cmd, ShErrKind::LoopBreak(0)),
"continue" => flowctl(cmd, ShErrKind::LoopContinue(0)),
"exit" => flowctl(cmd, ShErrKind::CleanExit(0)),
"shopt" => shopt(cmd),
"read" => read_builtin(cmd),
"trap" => trap(cmd),
"pushd" => pushd(cmd),
"popd" => popd(cmd),
"dirs" => dirs(cmd),
"eval" => eval::eval(cmd),
"readonly" => readonly(cmd),
"unset" => unset(cmd),
"complete" => complete_builtin(cmd),
"compgen" => compgen_builtin(cmd),
"map" => map::map(cmd),
"pop" => arr_pop(cmd),
"fpop" => arr_fpop(cmd),
"push" => arr_push(cmd),
"fpush" => arr_fpush(cmd),
"rotate" => arr_rotate(cmd),
"wait" => jobctl::wait(cmd),
"type" => intro::type_builtin(cmd),
"getopts" => getopts(cmd),
"keymap" => keymap::keymap(cmd),
"read_key" => read::read_key(cmd),
"autocmd" => autocmd(cmd),
"ulimit" => ulimit(cmd),
"umask" => umask_builtin(cmd),
"true" | ":" => {
state::set_status(0);
Ok(())
}
"false" => {
state::set_status(1);
Ok(())
}
_ => unimplemented!("Have not yet added support for builtin '{}'", cmd_raw),
};
if let Err(e) = result {
if !e.is_flow_control() {
state::set_status(1);
}
Err(e.with_context(context).with_redirs(redir_guard))
} else {
Ok(())
}
}
fn exec_cmd(&mut self, cmd: Node) -> ShResult<()> {
let blame = cmd.get_span().clone();
let context = cmd.context.clone();
let NdRule::Command { assignments, argv } = cmd.class else {
unreachable!()
};
let mut env_vars_to_unset = vec![];
if !assignments.is_empty() {
let assign_behavior = if argv.is_empty() {
AssignBehavior::Set
} else {
AssignBehavior::Export
};
env_vars_to_unset = self.set_assignments(assignments, assign_behavior)?;
}
let no_fork = cmd.flags.contains(NdFlags::NO_FORK);
if argv.is_empty() {
return Ok(());
}
self.io_stack.append_to_frame(cmd.redirs);
let exec_args = ExecArgs::new(argv).blame(blame)?;
let _guard = self.io_stack.pop_frame().redirect()?;
let job = self.job_stack.curr_job_mut().unwrap();
let existing_pgid = job.pgid();
let fg_job = self.fg_job;
let interactive = self.interactive;
let child_logic = |pgid: Option<Pid>| -> ! {
// For non-interactive exec-in-place (e.g. shed -c), skip process group
// and terminal setup — just transparently replace the current process.
if interactive || !no_fork {
// Put ourselves in the correct process group before exec.
// For the first child in a pipeline pgid is None, so we
// become our own group leader (setpgid(0,0)). For later
// children we join the leader's group.
let our_pgid = pgid.unwrap_or(Pid::from_raw(0));
let _ = setpgid(Pid::from_raw(0), our_pgid);
if fg_job {
let tty_pgid = if our_pgid == Pid::from_raw(0) {
nix::unistd::getpid()
} else {
our_pgid
};
let _ = tcsetpgrp(
unsafe { BorrowedFd::borrow_raw(*crate::libsh::sys::TTY_FILENO) },
tty_pgid,
);
}
}
if interactive || !no_fork {
crate::signal::reset_signals(fg_job);
}
let cmd = &exec_args.cmd.0;
let span = exec_args.cmd.1;
let Err(e) = execvpe(cmd, &exec_args.argv, &exec_args.envp);
// execvpe only returns on error
let cmd_str = cmd.to_str().unwrap().to_string();
match e {
Errno::ENOENT => {
ShErr::new(ShErrKind::NotFound, span.clone())
.labeled(span, format!("{cmd_str}: command not found"))
.with_context(context)
.print_error();
}
_ => {
ShErr::at(ShErrKind::Errno(e), span, format!("{e}"))
.with_context(context)
.print_error();
}
}
exit(e as i32)
};
if no_fork {
child_logic(existing_pgid);
}
match unsafe { fork()? } {
ForkResult::Child => child_logic(existing_pgid),
ForkResult::Parent { child } => {
// Close proc sub pipe fds - the child has inherited them
// and will access them via /proc/self/fd/N. Keeping them
// open here would prevent EOF on the pipe.
write_jobs(|j| j.drain_registered_fds());
let cmd_name = exec_args.cmd.0.to_str().unwrap();
let child_pgid = if let Some(pgid) = existing_pgid {
pgid
} else {
job.set_pgid(child);
child
};
let child_proc = ChildProc::new(child, Some(cmd_name), Some(child_pgid))?;
job.push_child(child_proc);
}
}
for var in env_vars_to_unset {
unsafe { std::env::set_var(&var, "") };
}
Ok(())
}
fn run_fork(&mut self, name: &str, f: impl FnOnce(&mut Self)) -> ShResult<()> {
let existing_pgid = self.job_stack.curr_job_mut().unwrap().pgid();
match unsafe { fork()? } {
ForkResult::Child => {
let _ = setpgid(Pid::from_raw(0), existing_pgid.unwrap_or(Pid::from_raw(0)));
f(self);
exit(state::get_status())
}
ForkResult::Parent { child } => {
write_jobs(|j| j.drain_registered_fds());
let job = self.job_stack.curr_job_mut().unwrap();
let child_pgid = if let Some(pgid) = existing_pgid {
pgid
} else {
job.set_pgid(child);
child
};
let child_proc = ChildProc::new(child, Some(name), Some(child_pgid))?;
job.push_child(child_proc);
Ok(())
}
}
}
fn set_assignments(&self, assigns: Vec<Node>, behavior: AssignBehavior) -> ShResult<Vec<String>> {
let mut new_env_vars = vec![];
let flags = match behavior {
AssignBehavior::Export => VarFlags::EXPORT,
AssignBehavior::Set => VarFlags::NONE,
};
for assign in assigns {
let is_arr = assign.flags.contains(NdFlags::ARR_ASSIGN);
let NdRule::Assignment { kind, var, val } = assign.class else {
unreachable!()
};
let var = var.span.as_str();
let val = if is_arr {
VarKind::arr_from_tk(val)?
} else {
VarKind::Str(val.expand()?.get_words().join(" "))
};
// Parse and expand array index BEFORE entering write_vars borrow
let indexed = state::parse_arr_bracket(var)
.map(|(name, idx_raw)| state::expand_arr_index(&idx_raw).map(|idx| (name, idx)))
.transpose()?;
match kind {
AssignKind::Eq => {
if let Some((name, idx)) = indexed {
write_vars(|v| v.set_var_indexed(&name, idx, val.to_string(), flags))?;
} else {
write_vars(|v| v.set_var(var, val, flags))?;
}
}
AssignKind::PlusEq => todo!(),
AssignKind::MinusEq => todo!(),
AssignKind::MultEq => todo!(),
AssignKind::DivEq => todo!(),
}
if matches!(behavior, AssignBehavior::Export) {
new_env_vars.push(var.to_string());
}
}
Ok(new_env_vars)
}
}
pub fn prepare_argv(argv: Vec<Tk>) -> ShResult<Vec<(String, Span)>> {
let mut args = vec![];
for arg in argv {
let span = arg.span.clone();
let expanded = arg.expand()?;
for exp in expanded.get_words() {
args.push((exp, span.clone()))
}
}
Ok(args)
}
/// Initialize the pipes for a pipeline
/// The first command gets `(None, WPipe)`
/// The last command gets `(RPipe, None)`
/// Commands inbetween get `(RPipe, WPipe)`
/// If there is only one command, it gets `(None, None)`
pub fn get_pipe_stack(num_cmds: usize) -> Vec<(Option<Redir>, Option<Redir>)> {
let mut stack = Vec::with_capacity(num_cmds);
let mut prev_read: Option<Redir> = None;
for i in 0..num_cmds {
if i == num_cmds - 1 {
stack.push((prev_read.take(), None));
} else {
let (rpipe, wpipe) = IoMode::get_pipes();
let r_redir = Redir::new(rpipe, RedirType::Input);
let w_redir = Redir::new(wpipe, RedirType::Output);
// Push (prev_read, Some(w_redir)) and set prev_read to r_redir
stack.push((prev_read.take(), Some(w_redir)));
prev_read = Some(r_redir);
}
}
stack
}
pub fn is_func(tk: Option<Tk>) -> bool {
let Some(tk) = tk else { return false };
read_logic(|l| l.get_func(&tk.to_string())).is_some()
}
pub fn is_subsh(tk: Option<Tk>) -> bool {
tk.is_some_and(|tk| tk.flags.contains(TkFlags::IS_SUBSH))
}
#[cfg(test)]
mod tests {
use crate::state;
use crate::testutil::{TestGuard, test_input};
// ===================== while/until status =====================
#[test]
fn while_loop_status_zero_after_completion() {
let _g = TestGuard::new();
test_input("while false; do :; done").unwrap();
assert_eq!(state::get_status(), 0);
}
#[test]
fn while_loop_status_zero_after_iterations() {
let _g = TestGuard::new();
test_input("X=0; while [[ $X -lt 3 ]]; do X=$((X+1)); done").unwrap();
assert_eq!(state::get_status(), 0);
}
#[test]
fn until_loop_status_zero_after_completion() {
let _g = TestGuard::new();
test_input("until true; do :; done").unwrap();
assert_eq!(state::get_status(), 0);
}
#[test]
fn until_loop_status_zero_after_iterations() {
let _g = TestGuard::new();
test_input("X=3; until [[ $X -le 0 ]]; do X=$((X-1)); done").unwrap();
assert_eq!(state::get_status(), 0);
}
#[test]
fn while_break_preserves_status() {
let _g = TestGuard::new();
test_input("while true; do break; done").unwrap();
assert_eq!(state::get_status(), 0);
}
#[test]
fn while_body_status_propagates() {
let _g = TestGuard::new();
test_input("X=0; while [[ $X -lt 1 ]]; do X=$((X+1)); false; done").unwrap();
// Loop body ended with `false` (status 1), but the loop itself
// completed normally when the condition failed, so status should be 0
assert_eq!(state::get_status(), 0);
}
// ===================== if/elif/else status =====================
#[test]
fn if_true_body_status() {
let _g = TestGuard::new();
test_input("if true; then echo ok; fi").unwrap();
assert_eq!(state::get_status(), 0);
}
#[test]
fn if_false_no_else_status() {
let _g = TestGuard::new();
test_input("if false; then echo ok; fi").unwrap();
// No branch taken, POSIX says status is 0
assert_eq!(state::get_status(), 0);
}
#[test]
fn if_else_branch_status() {
let _g = TestGuard::new();
test_input("if false; then true; else false; fi").unwrap();
assert_eq!(state::get_status(), 1);
}
// ===================== for loop status =====================
#[test]
fn for_loop_empty_list_status() {
let _g = TestGuard::new();
test_input("for x in; do echo $x; done").unwrap();
assert_eq!(state::get_status(), 0);
}
#[test]
fn for_loop_body_status() {
let _g = TestGuard::new();
test_input("for x in a b c; do true; done").unwrap();
assert_eq!(state::get_status(), 0);
}
// ===================== case status =====================
#[test]
fn case_match_status() {
let _g = TestGuard::new();
test_input("case foo in foo) true;; esac").unwrap();
assert_eq!(state::get_status(), 0);
}
#[test]
fn case_no_match_status() {
let _g = TestGuard::new();
test_input("case foo in bar) true;; esac").unwrap();
assert_eq!(state::get_status(), 0);
}
// ===================== other stuff =====================
#[test]
fn for_loop_var_zip() {
let g = TestGuard::new();
test_input("for a b in 1 2 3 4 5 6; do echo $a $b; done").unwrap();
let out = g.read_output();
assert_eq!(out, "1 2\n3 4\n5 6\n");
}
#[test]
fn for_loop_unsets_zipped() {
let g = TestGuard::new();
test_input("for a b c d in 1 2 3 4 5 6; do echo $a $b $c $d; done").unwrap();
let out = g.read_output();
assert_eq!(out, "1 2 3 4\n5 6\n");
}
// ===================== negation (!) status =====================
#[test]
fn negate_true() {
let _g = TestGuard::new();
test_input("! true").unwrap();
assert_eq!(state::get_status(), 1);
}
#[test]
fn negate_false() {
let _g = TestGuard::new();
test_input("! false").unwrap();
assert_eq!(state::get_status(), 0);
}
#[test]
fn double_negate_true() {
let _g = TestGuard::new();
test_input("! ! true").unwrap();
assert_eq!(state::get_status(), 0);
}
#[test]
fn double_negate_false() {
let _g = TestGuard::new();
test_input("! ! false").unwrap();
assert_eq!(state::get_status(), 1);
}
#[test]
fn negate_pipeline_last_cmd() {
let _g = TestGuard::new();
// pipeline status = last cmd (false) = 1, negated → 0
test_input("! true | false").unwrap();
assert_eq!(state::get_status(), 0);
}
#[test]
fn negate_pipeline_last_cmd_true() {
let _g = TestGuard::new();
// pipeline status = last cmd (true) = 0, negated → 1
test_input("! false | true").unwrap();
assert_eq!(state::get_status(), 1);
}
#[test]
fn negate_in_conjunction() {
let _g = TestGuard::new();
// ! binds to pipeline, not conjunction: (! (true && false)) && true
test_input("! (true && false) && true").unwrap();
assert_eq!(state::get_status(), 0);
}
#[test]
fn negate_in_if_condition() {
let g = TestGuard::new();
test_input("if ! false; then echo yes; fi").unwrap();
assert_eq!(state::get_status(), 0);
assert_eq!(g.read_output(), "yes\n");
}
}