/*
* Copyright (c) 2020, The SerenityOS developers.
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* 1. Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
* SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
* CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
* OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
#include "Shell.h"
#include "Execution.h"
#include "Formatter.h"
#include <AK/Function.h>
#include <AK/LexicalPath.h>
#include <AK/ScopeGuard.h>
#include <AK/StringBuilder.h>
#include <AK/TemporaryChange.h>
#include <LibCore/ArgsParser.h>
#include <LibCore/DirIterator.h>
#include <LibCore/Event.h>
#include <LibCore/EventLoop.h>
#include <LibCore/File.h>
#include <LibLine/Editor.h>
#include <errno.h>
#include <fcntl.h>
#include <inttypes.h>
#include <pwd.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/utsname.h>
#include <sys/wait.h>
#include <termios.h>
#include <unistd.h>
static bool s_disable_hyperlinks = false;
extern char** environ;
//#define SH_DEBUG
namespace Shell {
// FIXME: This should eventually be removed once we've established that
// waitpid() is not passed the same job twice.
#ifdef __serenity__
# define ENSURE_WAITID_ONCE
#endif
void Shell::setup_signals()
{
if (m_should_reinstall_signal_handlers) {
Core::EventLoop::register_signal(SIGCHLD, [this](int) {
#ifdef SH_DEBUG
dbgln("SIGCHLD!");
#endif
notify_child_event();
});
Core::EventLoop::register_signal(SIGTSTP, [this](auto) {
auto job = current_job();
kill_job(job, SIGTSTP);
if (job) {
job->set_is_suspended(true);
job->unblock();
}
});
}
}
void Shell::print_path(const String& path)
{
if (s_disable_hyperlinks || !m_is_interactive) {
printf("%s", path.characters());
return;
}
printf("\033]8;;file://%s%s\033\\%s\033]8;;\033\\", hostname, path.characters(), path.characters());
}
String Shell::prompt() const
{
auto build_prompt = [&]() -> String {
auto* ps1 = getenv("PROMPT");
if (!ps1) {
if (uid == 0)
return "# ";
StringBuilder builder;
builder.appendf("\033]0;%s@%s:%s\007", username.characters(), hostname, cwd.characters());
builder.appendf("\033[31;1m%s\033[0m@\033[37;1m%s\033[0m:\033[32;1m%s\033[0m$> ", username.characters(), hostname, cwd.characters());
return builder.to_string();
}
StringBuilder builder;
for (char* ptr = ps1; *ptr; ++ptr) {
if (*ptr == '\\') {
++ptr;
if (!*ptr)
break;
switch (*ptr) {
case 'X':
builder.append("\033]0;");
break;
case 'a':
builder.append(0x07);
break;
case 'e':
builder.append(0x1b);
break;
case 'u':
builder.append(username);
break;
case 'h':
builder.append(hostname);
break;
case 'w': {
String home_path = getenv("HOME");
if (cwd.starts_with(home_path)) {
builder.append('~');
builder.append(cwd.substring_view(home_path.length(), cwd.length() - home_path.length()));
} else {
builder.append(cwd);
}
break;
}
case 'p':
builder.append(uid == 0 ? '#' : '$');
break;
}
continue;
}
builder.append(*ptr);
}
return builder.to_string();
};
return build_prompt();
}
String Shell::expand_tilde(const String& expression)
{
ASSERT(expression.starts_with('~'));
StringBuilder login_name;
size_t first_slash_index = expression.length();
for (size_t i = 1; i < expression.length(); ++i) {
if (expression[i] == '/') {
first_slash_index = i;
break;
}
login_name.append(expression[i]);
}
StringBuilder path;
for (size_t i = first_slash_index; i < expression.length(); ++i)
path.append(expression[i]);
if (login_name.is_empty()) {
const char* home = getenv("HOME");
if (!home) {
auto passwd = getpwuid(getuid());
ASSERT(passwd && passwd->pw_dir);
return String::format("%s/%s", passwd->pw_dir, path.to_string().characters());
}
return String::format("%s/%s", home, path.to_string().characters());
}
auto passwd = getpwnam(login_name.to_string().characters());
if (!passwd)
return expression;
ASSERT(passwd->pw_dir);
return String::format("%s/%s", passwd->pw_dir, path.to_string().characters());
}
bool Shell::is_glob(const StringView& s)
{
for (size_t i = 0; i < s.length(); i++) {
char c = s.characters_without_null_termination()[i];
if (c == '*' || c == '?')
return true;
}
return false;
}
Vector<StringView> Shell::split_path(const StringView& path)
{
Vector<StringView> parts;
size_t substart = 0;
for (size_t i = 0; i < path.length(); i++) {
char ch = path[i];
if (ch != '/')
continue;
size_t sublen = i - substart;
if (sublen != 0)
parts.append(path.substring_view(substart, sublen));
substart = i + 1;
}
size_t taillen = path.length() - substart;
if (taillen != 0)
parts.append(path.substring_view(substart, taillen));
return parts;
}
Vector<String> Shell::expand_globs(const StringView& path, StringView base)
{
auto explicitly_set_base = false;
if (path.starts_with('/')) {
base = "/";
explicitly_set_base = true;
}
auto parts = split_path(path);
String base_string = base;
struct stat statbuf;
if (lstat(base_string.characters(), &statbuf) < 0) {
perror("lstat");
return {};
}
StringBuilder resolved_base_path_builder;
resolved_base_path_builder.append(Core::File::real_path_for(base));
if (S_ISDIR(statbuf.st_mode))
resolved_base_path_builder.append('/');
auto resolved_base = resolved_base_path_builder.string_view();
auto results = expand_globs(move(parts), resolved_base);
if (explicitly_set_base && base == "/")
resolved_base = resolved_base.substring_view(1, resolved_base.length() - 1);
for (auto& entry : results) {
entry = entry.substring(resolved_base.length(), entry.length() - resolved_base.length());
if (entry.is_empty())
entry = ".";
}
// Make the output predictable and nice.
quick_sort(results);
return results;
}
Vector<String> Shell::expand_globs(Vector<StringView> path_segments, const StringView& base)
{
if (path_segments.is_empty()) {
String base_str = base;
if (access(base_str.characters(), F_OK) == 0)
return { move(base_str) };
return {};
}
auto first_segment = path_segments.take_first();
if (is_glob(first_segment)) {
Vector<String> result;
Core::DirIterator di(base, Core::DirIterator::SkipParentAndBaseDir);
if (di.has_error())
return {};
while (di.has_next()) {
String path = di.next_path();
// Dotfiles have to be explicitly requested
if (path[0] == '.' && first_segment[0] != '.')
continue;
if (path.matches(first_segment, CaseSensitivity::CaseSensitive)) {
StringBuilder builder;
builder.append(base);
if (!base.ends_with('/'))
builder.append('/');
builder.append(path);
result.append(expand_globs(path_segments, builder.string_view()));
}
}
return result;
} else {
StringBuilder builder;
builder.append(base);
if (!base.ends_with('/'))
builder.append('/');
builder.append(first_segment);
return expand_globs(move(path_segments), builder.string_view());
}
}
Vector<AST::Command> Shell::expand_aliases(Vector<AST::Command> initial_commands)
{
Vector<AST::Command> commands;
Function<void(AST::Command&)> resolve_aliases_and_append = [&](auto& command) {
if (!command.argv.is_empty()) {
auto alias = resolve_alias(command.argv[0]);
if (!alias.is_null()) {
auto argv0 = command.argv.take_first();
auto subcommand_ast = Parser { alias }.parse();
if (subcommand_ast) {
while (subcommand_ast->is_execute()) {
auto* ast = static_cast<AST::Execute*>(subcommand_ast.ptr());
subcommand_ast = ast->command();
}
auto subcommand_nonnull = subcommand_ast.release_nonnull();
NonnullRefPtr<AST::Node> substitute = adopt(*new AST::Join(subcommand_nonnull->position(),
subcommand_nonnull,
adopt(*new AST::CommandLiteral(subcommand_nonnull->position(), command))));
auto res = substitute->run(*this);
for (auto& subst_command : res->resolve_as_commands(*this)) {
if (!subst_command.argv.is_empty() && subst_command.argv.first() == argv0) // Disallow an alias resolving to itself.
commands.append(subst_command);
else
resolve_aliases_and_append(subst_command);
}
} else {
commands.append(command);
}
} else {
commands.append(command);
}
} else {
commands.append(command);
}
};
for (auto& command : initial_commands)
resolve_aliases_and_append(command);
return commands;
}
String Shell::resolve_path(String path) const
{
if (!path.starts_with('/'))
path = String::format("%s/%s", cwd.characters(), path.characters());
return Core::File::real_path_for(path);
}
Shell::LocalFrame* Shell::find_frame_containing_local_variable(const String& name)
{
for (size_t i = m_local_frames.size(); i > 0; --i) {
auto& frame = m_local_frames[i - 1];
if (frame.local_variables.contains(name))
return &frame;
}
return nullptr;
}
RefPtr<AST::Value> Shell::lookup_local_variable(const String& name)
{
if (auto* frame = find_frame_containing_local_variable(name))
return frame->local_variables.get(name).value();
if (auto index = name.to_uint(); index.has_value())
return get_argument(index.value());
return nullptr;
}
RefPtr<AST::Value> Shell::get_argument(size_t index)
{
if (index == 0)
return adopt(*new AST::StringValue(current_script));
--index;
if (auto argv = lookup_local_variable("ARGV")) {
if (argv->is_list_without_resolution()) {
AST::ListValue* list = static_cast<AST::ListValue*>(argv.ptr());
if (list->values().size() <= index)
return nullptr;
return list->values().at(index);
}
if (index != 0)
return nullptr;
return argv;
}
return nullptr;
}
String Shell::local_variable_or(const String& name, const String& replacement)
{
auto value = lookup_local_variable(name);
if (value) {
StringBuilder builder;
builder.join(" ", value->resolve_as_list(*this));
return builder.to_string();
}
return replacement;
}
void Shell::set_local_variable(const String& name, RefPtr<AST::Value> value, bool only_in_current_frame)
{
if (!only_in_current_frame) {
if (auto* frame = find_frame_containing_local_variable(name)) {
frame->local_variables.set(name, move(value));
return;
}
}
m_local_frames.last().local_variables.set(name, move(value));
}
void Shell::unset_local_variable(const String& name, bool only_in_current_frame)
{
if (!only_in_current_frame) {
if (auto* frame = find_frame_containing_local_variable(name))
frame->local_variables.remove(name);
return;
}
m_local_frames.last().local_variables.remove(name);
}
void Shell::define_function(String name, Vector<String> argnames, RefPtr<AST::Node> body)
{
add_entry_to_cache(name);
m_functions.set(name, { name, move(argnames), move(body) });
}
bool Shell::has_function(const String& name)
{
return m_functions.contains(name);
}
bool Shell::invoke_function(const AST::Command& command, int& retval)
{
if (command.argv.is_empty())
return false;
StringView name = command.argv.first();
TemporaryChange<String> script_change { current_script, name };
auto function_option = m_functions.get(name);
if (!function_option.has_value())
return false;
auto& function = function_option.value();
if (!function.body) {
retval = 0;
return true;
}
if (command.argv.size() - 1 < function.arguments.size()) {
fprintf(stderr, "Shell: expected at least %zu arguments to %s, but got %zu\n", function.arguments.size(), function.name.characters(), command.argv.size() - 1);
retval = 1;
return true;
}
auto frame = push_frame(String::formatted("function {}", function.name));
size_t index = 0;
for (auto& arg : function.arguments) {
++index;
set_local_variable(arg, adopt(*new AST::StringValue(command.argv[index])), true);
}
auto argv = command.argv;
argv.take_first();
set_local_variable("ARGV", adopt(*new AST::ListValue(move(argv))), true);
Core::EventLoop loop;
setup_signals();
function.body->run(*this);
retval = last_return_code;
return true;
}
String Shell::format(const StringView& source, ssize_t& cursor) const
{
Formatter formatter(source, cursor);
auto result = formatter.format();
cursor = formatter.cursor();
return result;
}
Shell::Frame Shell::push_frame(String name)
{
m_local_frames.append(make<LocalFrame>(name, decltype(LocalFrame::local_variables) {}));
#ifdef SH_DEBUG
dbgln("New frame '{}' at {:p}", name, &m_local_frames.last());
#endif
return { m_local_frames, m_local_frames.last() };
}
void Shell::pop_frame()
{
ASSERT(m_local_frames.size() > 1);
m_local_frames.take_last();
}
Shell::Frame::~Frame()
{
if (!should_destroy_frame)
return;
if (&frames.last() != &frame) {
dbgln("Frame destruction order violation near {:p} (container = {:p}) in '{}'", &frame, this, frame.name);
dbgln("Current frames:");
for (auto& frame : frames)
dbgln("- {:p}: {}", &frame, frame.name);
ASSERT_NOT_REACHED();
}
frames.take_last();
}
String Shell::resolve_alias(const String& name) const
{
return m_aliases.get(name).value_or({});
}
bool Shell::is_runnable(const StringView& name)
{
if (access(name.to_string().characters(), X_OK) == 0)
return true;
return !!binary_search(cached_path.span(), name.to_string(), [](const String& name, const String& program) -> int {
return strcmp(name.characters(), program.characters());
});
}
int Shell::run_command(const StringView& cmd)
{
// The default-constructed mode of the shell
// should not be used for execution!
ASSERT(!m_default_constructed);
if (cmd.is_empty())
return 0;
auto command = Parser(cmd).parse();
if (!command)
return 0;
#ifdef SH_DEBUG
dbgln("Command follows");
command->dump(0);
#endif
if (command->is_syntax_error()) {
auto& error_node = command->syntax_error_node();
auto& position = error_node.position();
fprintf(stderr, "Shell: Syntax error in command: %s\n", error_node.error_text().characters());
fprintf(stderr, "Around '%.*s' at %zu:%zu to %zu:%zu\n",
(int)min(position.end_offset - position.start_offset, (size_t)10),
cmd.characters_without_null_termination() + position.start_offset,
position.start_line.line_column, position.start_line.line_number,
position.end_line.line_column, position.end_line.line_number);
return 1;
}
tcgetattr(0, &termios);
command->run(*this);
return last_return_code;
}
RefPtr<Job> Shell::run_command(const AST::Command& command)
{
FileDescriptionCollector fds;
if (options.verbose)
warnln("+ {}", command);
// If the command is empty, store the redirections and apply them to all later commands.
if (command.argv.is_empty() && !command.should_immediately_execute_next) {
m_global_redirections.append(command.redirections);
return nullptr;
}
// Resolve redirections.
NonnullRefPtrVector<AST::Rewiring> rewirings;
auto resolve_redirection = [&](auto& redirection) -> IterationDecision {
auto rewiring_result = redirection.apply();
if (rewiring_result.is_error()) {
if (!rewiring_result.error().is_empty())
fprintf(stderr, "error: %s\n", rewiring_result.error().characters());
return IterationDecision::Break;
}
auto& rewiring = rewiring_result.value();
if (rewiring->fd_action != AST::Rewiring::Close::ImmediatelyCloseNew)
rewirings.append(*rewiring);
if (rewiring->fd_action == AST::Rewiring::Close::Old) {
fds.add(rewiring->old_fd);
} else if (rewiring->fd_action == AST::Rewiring::Close::New) {
if (rewiring->new_fd != -1)
fds.add(rewiring->new_fd);
} else if (rewiring->fd_action == AST::Rewiring::Close::ImmediatelyCloseNew) {
fds.add(rewiring->new_fd);
} else if (rewiring->fd_action == AST::Rewiring::Close::RefreshNew) {
ASSERT(rewiring->other_pipe_end);
int pipe_fd[2];
int rc = pipe(pipe_fd);
if (rc < 0) {
perror("pipe(RedirRefresh)");
return IterationDecision::Break;
}
rewiring->new_fd = pipe_fd[1];
rewiring->other_pipe_end->new_fd = pipe_fd[0]; // This fd will be added to the collection on one of the next iterations.
fds.add(pipe_fd[1]);
} else if (rewiring->fd_action == AST::Rewiring::Close::RefreshOld) {
ASSERT(rewiring->other_pipe_end);
int pipe_fd[2];
int rc = pipe(pipe_fd);
if (rc < 0) {
perror("pipe(RedirRefresh)");
return IterationDecision::Break;
}
rewiring->old_fd = pipe_fd[1];
rewiring->other_pipe_end->old_fd = pipe_fd[0]; // This fd will be added to the collection on one of the next iterations.
fds.add(pipe_fd[1]);
}
return IterationDecision::Continue;
};
auto apply_rewirings = [&] {
for (auto& rewiring : rewirings) {
#ifdef SH_DEBUG
dbgln("in {}<{}>, dup2({}, {})", command.argv.is_empty() ? "(<Empty>)" : command.argv[0].characters(), getpid(), rewiring.old_fd, rewiring.new_fd);
#endif
int rc = dup2(rewiring.old_fd, rewiring.new_fd);
if (rc < 0) {
perror("dup2(run)");
return IterationDecision::Break;
}
// {new,old}_fd is closed via the `fds` collector, but rewiring.other_pipe_end->{new,old}_fd
// isn't yet in that collector when the first child spawns.
if (rewiring.other_pipe_end) {
if (rewiring.fd_action == AST::Rewiring::Close::RefreshNew) {
if (rewiring.other_pipe_end && close(rewiring.other_pipe_end->new_fd) < 0)
perror("close other pipe end");
} else if (rewiring.fd_action == AST::Rewiring::Close::RefreshOld) {
if (rewiring.other_pipe_end && close(rewiring.other_pipe_end->old_fd) < 0)
perror("close other pipe end");
}
}
}
return IterationDecision::Continue;
};
TemporaryChange signal_handler_install { m_should_reinstall_signal_handlers, false };
for (auto& redirection : m_global_redirections) {
if (resolve_redirection(redirection) == IterationDecision::Break)
return nullptr;
}
for (auto& redirection : command.redirections) {
if (resolve_redirection(redirection) == IterationDecision::Break)
return nullptr;
}
if (command.should_wait && run_builtin(command, rewirings, last_return_code)) {
for (auto& next_in_chain : command.next_chain)
run_tail(command, next_in_chain, last_return_code);
return nullptr;
}
auto can_be_run_in_current_process = command.should_wait && !command.pipeline && !command.argv.is_empty();
if (can_be_run_in_current_process && has_function(command.argv.first())) {
SavedFileDescriptors fds { rewirings };
for (auto& rewiring : rewirings) {
int rc = dup2(rewiring.old_fd, rewiring.new_fd);
if (rc < 0) {
perror("dup2(run)");
return nullptr;
}
}
if (invoke_function(command, last_return_code)) {
for (auto& next_in_chain : command.next_chain)
run_tail(command, next_in_chain, last_return_code);
return nullptr;
}
}
Vector<const char*> argv;
Vector<String> copy_argv = command.argv;
argv.ensure_capacity(command.argv.size() + 1);
for (auto& arg : copy_argv)
argv.append(arg.characters());
argv.append(nullptr);
int sync_pipe[2];
if (pipe(sync_pipe) < 0) {
perror("pipe");
return nullptr;
}
pid_t child = fork();
if (child < 0) {
perror("fork");
return nullptr;
}
if (child == 0) {
close(sync_pipe[1]);
m_is_subshell = true;
m_pid = getpid();
Core::EventLoop::notify_forked(Core::EventLoop::ForkEvent::Child);
TemporaryChange signal_handler_install { m_should_reinstall_signal_handlers, true };
if (apply_rewirings() == IterationDecision::Break)
_exit(126);
fds.collect();
u8 c;
while (read(sync_pipe[0], &c, 1) < 0) {
if (errno != EINTR) {
perror("read");
// There's nothing interesting we can do here.
break;
}
}
#ifdef SH_DEBUG
dbgln("Synced up with parent, we're good to exec()");
#endif
close(sync_pipe[0]);
if (!m_is_subshell && command.should_wait)
tcsetattr(0, TCSANOW, &default_termios);
if (command.should_immediately_execute_next) {
ASSERT(command.argv.is_empty());
Core::EventLoop mainloop;
setup_signals();
for (auto& next_in_chain : command.next_chain)
run_tail(command, next_in_chain, 0);
_exit(last_return_code);
}
if (run_builtin(command, {}, last_return_code))
_exit(last_return_code);
if (invoke_function(command, last_return_code))
_exit(last_return_code);
// We no longer need the jobs here.
jobs.clear();
int rc = execvp(argv[0], const_cast<char* const*>(argv.data()));
if (rc < 0) {
int saved_errno = errno;
struct stat st;
if (stat(argv[0], &st)) {
fprintf(stderr, "stat(%s): %s\n", argv[0], strerror(errno));
_exit(126);
}
if (!(st.st_mode & S_IXUSR)) {
fprintf(stderr, "%s: Not executable\n", argv[0]);
_exit(126);
}
if (saved_errno == ENOENT) {
int shebang_fd = open(argv[0], O_RDONLY);
auto close_argv = ScopeGuard([shebang_fd]() { if (shebang_fd >= 0) close(shebang_fd); });
char shebang[256] {};
ssize_t num_read = -1;
if ((shebang_fd >= 0) && ((num_read = read(shebang_fd, shebang, sizeof(shebang))) >= 2) && (StringView(shebang).starts_with("#!"))) {
StringView shebang_path_view(&shebang[2], num_read - 2);
Optional<size_t> newline_pos = shebang_path_view.find_first_of("\n\r");
shebang[newline_pos.has_value() ? (newline_pos.value() + 2) : num_read] = '\0';
argv[0] = shebang;
int rc = execvp(argv[0], const_cast<char* const*>(argv.data()));
if (rc < 0)
fprintf(stderr, "%s: Invalid interpreter \"%s\": %s\n", argv[0], &shebang[2], strerror(errno));
} else
fprintf(stderr, "%s: Command not found.\n", argv[0]);
} else {
if (S_ISDIR(st.st_mode)) {
fprintf(stderr, "Shell: %s: Is a directory\n", argv[0]);
_exit(126);
}
fprintf(stderr, "execvp(%s): %s\n", argv[0], strerror(saved_errno));
}
_exit(126);
}
ASSERT_NOT_REACHED();
}
close(sync_pipe[0]);
bool is_first = !command.pipeline || (command.pipeline && command.pipeline->pgid == -1);
if (command.pipeline) {
if (is_first) {
command.pipeline->pgid = child;
}
}
pid_t pgid = is_first ? child : (command.pipeline ? command.pipeline->pgid : child);
if (!m_is_subshell || command.pipeline) {
if (setpgid(child, pgid) < 0 && m_is_interactive)
perror("setpgid");
if (!m_is_subshell) {
if (tcsetpgrp(STDOUT_FILENO, pgid) != 0 && m_is_interactive)
perror("tcsetpgrp(OUT)");
if (tcsetpgrp(STDIN_FILENO, pgid) != 0 && m_is_interactive)
perror("tcsetpgrp(IN)");
}
}
while (write(sync_pipe[1], "x", 1) < 0) {
if (errno != EINTR) {
perror("write");
// There's nothing interesting we can do here.
break;
}
}
close(sync_pipe[1]);
StringBuilder cmd;
cmd.join(" ", command.argv);
auto command_copy = AST::Command(command);
// Clear the next chain if it's to be immediately executed
// as the child will run this chain.
if (command.should_immediately_execute_next)
command_copy.next_chain.clear();
auto job = Job::create(child, pgid, cmd.build(), find_last_job_id() + 1, move(command_copy));
jobs.set((u64)child, job);
job->on_exit = [this](auto job) {
if (!job->exited())
return;
restore_ios();
if (job->is_running_in_background() && job->should_announce_exit())
warnln("Shell: Job {} ({}) exited\n", job->job_id(), job->cmd().characters());
else if (job->signaled() && job->should_announce_signal())
warnln("Shell: Job {} ({}) {}\n", job->job_id(), job->cmd().characters(), strsignal(job->termination_signal()));
last_return_code = job->exit_code();
job->disown();
run_tail(job);
};
fds.collect();
return *job;
}
void Shell::run_tail(const AST::Command& invoking_command, const AST::NodeWithAction& next_in_chain, int head_exit_code)
{
auto evaluate = [&] {
if (next_in_chain.node->would_execute()) {
next_in_chain.node->run(*this);
return;
}
auto node = next_in_chain.node;
if (!invoking_command.should_wait)
node = adopt(static_cast<AST::Node&>(*new AST::Background(next_in_chain.node->position(), move(node))));
adopt(static_cast<AST::Node&>(*new AST::Execute(next_in_chain.node->position(), move(node))))->run(*this);
};
switch (next_in_chain.action) {
case AST::NodeWithAction::And:
if (head_exit_code == 0)
evaluate();
break;
case AST::NodeWithAction::Or:
if (head_exit_code != 0)
evaluate();
break;
case AST::NodeWithAction::Sequence:
evaluate();
break;
}
}
void Shell::run_tail(RefPtr<Job> job)
{
if (auto cmd = job->command_ptr()) {
deferred_invoke([=, this](auto&) {
for (auto& next_in_chain : cmd->next_chain) {
run_tail(*cmd, next_in_chain, job->exit_code());
}
});
}
}
NonnullRefPtrVector<Job> Shell::run_commands(Vector<AST::Command>& commands)
{
NonnullRefPtrVector<Job> spawned_jobs;
for (auto& command : commands) {
#ifdef SH_DEBUG
dbgln("Command");
for (auto& arg : command.argv)
dbgln("argv: {}", arg);
for (auto& redir : command.redirections) {
if (redir.is_path_redirection()) {
auto path_redir = (const AST::PathRedirection*)&redir;
dbgln("redir path '{}' <-({})-> {}", path_redir->path, (int)path_redir->direction, path_redir->fd);
} else if (redir.is_fd_redirection()) {
auto* fdredir = (const AST::FdRedirection*)&redir;
dbgln("redir fd {} -> {}", fdredir->old_fd, fdredir->new_fd);
} else if (redir.is_close_redirection()) {
auto close_redir = (const AST::CloseRedirection*)&redir;
dbgln("close fd {}", close_redir->fd);
} else {
ASSERT_NOT_REACHED();
}
}
#endif
auto job = run_command(command);
if (!job)
continue;
spawned_jobs.append(*job);
if (command.should_wait) {
block_on_job(job);
} else {
job->set_running_in_background(true);
if (!command.is_pipe_source && command.should_notify_if_in_background)
job->set_should_announce_exit(true);
}
}
return spawned_jobs;
}
bool Shell::run_file(const String& filename, bool explicitly_invoked)
{
TemporaryChange script_change { current_script, filename };
TemporaryChange interactive_change { m_is_interactive, false };
auto file_result = Core::File::open(filename, Core::File::ReadOnly);
if (file_result.is_error()) {
if (explicitly_invoked)
fprintf(stderr, "Failed to open %s: %s\n", filename.characters(), file_result.error().characters());
else
dbgln("open() failed for '{}' with {}", filename, file_result.error());
return false;
}
auto file = file_result.value();
auto data = file->read_all();
run_command(data);
return true;
}
void Shell::restore_ios()
{
if (m_is_subshell)
return;
tcsetattr(0, TCSANOW, &termios);
tcsetpgrp(STDOUT_FILENO, m_pid);
tcsetpgrp(STDIN_FILENO, m_pid);
}
void Shell::block_on_pipeline(RefPtr<AST::Pipeline> pipeline)
{
if (!pipeline)
return;
for (auto& it : jobs) {
if (auto cmd = it.value->command_ptr(); cmd->pipeline == pipeline && cmd->is_pipe_source)
block_on_job(it.value);
}
}
void Shell::block_on_job(RefPtr<Job> job)
{
TemporaryChange<const Job*> current_job { m_current_job, job.ptr() };
if (!job)
return;
if (job->is_suspended())
return; // We cannot wait for a suspended job.
ScopeGuard io_restorer { [&]() {
if (job->exited() && !job->is_running_in_background()) {
restore_ios();
}
} };
Core::EventLoop loop;
job->on_exit = [&, old_exit = move(job->on_exit)](auto job) {
if (old_exit)
old_exit(job);
loop.quit(0);
};
if (job->exited())
return;
loop.exec();
// If the job is part of a pipeline, wait for the rest of the members too.
if (auto command = job->command_ptr())
block_on_pipeline(command->pipeline);
}
String Shell::get_history_path()
{
if (auto histfile = getenv("HISTFILE"))
return { histfile };
return String::formatted("{}/.history", home);
}
String Shell::escape_token(const String& token)
{
StringBuilder builder;
for (auto c : token) {
switch (c) {
case '\'':
case '"':
case '$':
case '|':
case '>':
case '<':
case '&':
case '\\':
case ' ':
builder.append('\\');
break;
default:
break;
}
builder.append(c);
}
return builder.build();
}
String Shell::unescape_token(const String& token)
{
StringBuilder builder;
enum {
Free,
Escaped
} state { Free };
for (auto c : token) {
switch (state) {
case Escaped:
builder.append(c);
state = Free;
break;
case Free:
if (c == '\\')
state = Escaped;
else
builder.append(c);
break;
}
}
if (state == Escaped)
builder.append('\\');
return builder.build();
}
void Shell::cache_path()
{
if (!cached_path.is_empty())
cached_path.clear_with_capacity();
// Add shell builtins to the cache.
for (const auto& builtin_name : builtin_names)
cached_path.append(escape_token(builtin_name));
// Add aliases to the cache.
for (const auto& alias : m_aliases) {
auto name = escape_token(alias.key);
if (cached_path.contains_slow(name))
continue;
cached_path.append(name);
}
String path = getenv("PATH");
if (!path.is_empty()) {
auto directories = path.split(':');
for (const auto& directory : directories) {
Core::DirIterator programs(directory.characters(), Core::DirIterator::SkipDots);
while (programs.has_next()) {
auto program = programs.next_path();
String program_path = String::format("%s/%s", directory.characters(), program.characters());
auto escaped_name = escape_token(program);
if (cached_path.contains_slow(escaped_name))
continue;
if (access(program_path.characters(), X_OK) == 0)
cached_path.append(escaped_name);
}
}
}
quick_sort(cached_path);
}
void Shell::add_entry_to_cache(const String& entry)
{
size_t index = 0;
auto match = binary_search(
cached_path.span(), entry, [](const String& name, const String& program) -> int {
return strcmp(name.characters(), program.characters());
},
&index);
if (match)
return;
while (index < cached_path.size() && strcmp(cached_path[index].characters(), entry.characters()) < 0) {
index++;
}
cached_path.insert(index, entry);
}
void Shell::highlight(Line::Editor& editor) const
{
auto line = editor.line();
Parser parser(line);
auto ast = parser.parse();
if (!ast)
return;
ast->highlight_in_editor(editor, const_cast<Shell&>(*this));
}
Vector<Line::CompletionSuggestion> Shell::complete()
{
auto line = m_editor->line(m_editor->cursor());
Parser parser(line);
auto ast = parser.parse();
if (!ast)
return {};
return ast->complete_for_editor(*this, line.length());
}
Vector<Line::CompletionSuggestion> Shell::complete_path(const String& base, const String& part, size_t offset)
{
auto token = offset ? part.substring_view(0, offset) : "";
StringView original_token = token;
String path;
ssize_t last_slash = token.length() - 1;
while (last_slash >= 0 && token[last_slash] != '/')
--last_slash;
StringBuilder path_builder;
auto init_slash_part = token.substring_view(0, last_slash + 1);
auto last_slash_part = token.substring_view(last_slash + 1, token.length() - last_slash - 1);
// Depending on the base, we will have to prepend cwd.
if (base.is_empty()) {
// '' /foo -> absolute
// '' foo -> relative
if (!token.starts_with('/'))
path_builder.append(cwd);
path_builder.append('/');
path_builder.append(init_slash_part);
} else {
// /foo * -> absolute
// foo * -> relative
if (!base.starts_with('/'))
path_builder.append(cwd);
path_builder.append('/');
path_builder.append(base);
path_builder.append('/');
path_builder.append(init_slash_part);
}
path = path_builder.build();
token = last_slash_part;
// the invariant part of the token is actually just the last segment
// e. in `cd /foo/bar', 'bar' is the invariant
// since we are not suggesting anything starting with
// `/foo/', but rather just `bar...'
auto token_length = escape_token(token).length();
if (m_editor)
m_editor->suggest(token_length, original_token.length() - token_length);
// only suggest dot-files if path starts with a dot
Core::DirIterator files(path,
token.starts_with('.') ? Core::DirIterator::SkipParentAndBaseDir : Core::DirIterator::SkipDots);
Vector<Line::CompletionSuggestion> suggestions;
while (files.has_next()) {
auto file = files.next_path();
if (file.starts_with(token)) {
struct stat program_status;
String file_path = String::format("%s/%s", path.characters(), file.characters());
int stat_error = stat(file_path.characters(), &program_status);
if (!stat_error) {
if (S_ISDIR(program_status.st_mode)) {
suggestions.append({ escape_token(file), "/" });
} else {
suggestions.append({ escape_token(file), " " });
}
suggestions.last().input_offset = token_length;
}
}
}
return suggestions;
}
Vector<Line::CompletionSuggestion> Shell::complete_program_name(const String& name, size_t offset)
{
auto match = binary_search(cached_path.span(), name, [](const String& name, const String& program) -> int {
return strncmp(name.characters(), program.characters(), name.length());
});
if (!match)
return complete_path("", name, offset);
String completion = *match;
auto token_length = escape_token(name).length();
if (m_editor)
m_editor->suggest(token_length, 0);
// Now that we have a program name starting with our token, we look at
// other program names starting with our token and cut off any mismatching
// characters.
Vector<Line::CompletionSuggestion> suggestions;
int index = match - cached_path.data();
for (int i = index - 1; i >= 0 && cached_path[i].starts_with(name); --i) {
suggestions.append({ cached_path[i], " " });
suggestions.last().input_offset = token_length;
}
for (size_t i = index + 1; i < cached_path.size() && cached_path[i].starts_with(name); ++i) {
suggestions.append({ cached_path[i], " " });
suggestions.last().input_offset = token_length;
}
suggestions.append({ cached_path[index], " " });
suggestions.last().input_offset = token_length;
return suggestions;
}
Vector<Line::CompletionSuggestion> Shell::complete_variable(const String& name, size_t offset)
{
Vector<Line::CompletionSuggestion> suggestions;
auto pattern = offset ? name.substring_view(0, offset) : "";
if (m_editor)
m_editor->suggest(offset);
// Look at local variables.
for (auto& frame : m_local_frames) {
for (auto& variable : frame.local_variables) {
if (variable.key.starts_with(pattern) && !suggestions.contains_slow(variable.key))
suggestions.append(variable.key);
}
}
// Look at the environment.
for (auto i = 0; environ[i]; ++i) {
auto entry = StringView { environ[i] };
if (entry.starts_with(pattern)) {
auto parts = entry.split_view('=');
if (parts.is_empty() || parts.first().is_empty())
continue;
String name = parts.first();
if (suggestions.contains_slow(name))
continue;
suggestions.append(move(name));
suggestions.last().input_offset = offset;
}
}
return suggestions;
}
Vector<Line::CompletionSuggestion> Shell::complete_user(const String& name, size_t offset)
{
Vector<Line::CompletionSuggestion> suggestions;
auto pattern = offset ? name.substring_view(0, offset) : "";
if (m_editor)
m_editor->suggest(offset);
Core::DirIterator di("/home", Core::DirIterator::SkipParentAndBaseDir);
if (di.has_error())
return suggestions;
while (di.has_next()) {
String name = di.next_path();
if (name.starts_with(pattern)) {
suggestions.append(name);
suggestions.last().input_offset = offset;
}
}
return suggestions;
}
Vector<Line::CompletionSuggestion> Shell::complete_option(const String& program_name, const String& option, size_t offset)
{
size_t start = 0;
while (start < option.length() && option[start] == '-' && start < 2)
++start;
auto option_pattern = offset > start ? option.substring_view(start, offset - start) : "";
if (m_editor)
m_editor->suggest(offset);
Vector<Line::CompletionSuggestion> suggestions;
dbgln("Shell::complete_option({}, {})", program_name, option_pattern);
// FIXME: Figure out how to do this stuff.
if (has_builtin(program_name)) {
// Complete builtins.
if (program_name == "setopt") {
bool negate = false;
if (option_pattern.starts_with("no_")) {
negate = true;
option_pattern = option_pattern.substring_view(3, option_pattern.length() - 3);
}
auto maybe_negate = [&](const StringView& view) {
static StringBuilder builder;
builder.clear();
builder.append("--");
if (negate)
builder.append("no_");
builder.append(view);
return builder.to_string();
};
#define __ENUMERATE_SHELL_OPTION(name, d_, descr_) \
if (StringView { #name }.starts_with(option_pattern)) { \
suggestions.append(maybe_negate(#name)); \
suggestions.last().input_offset = offset; \
}
ENUMERATE_SHELL_OPTIONS();
#undef __ENUMERATE_SHELL_OPTION
return suggestions;
}
}
return suggestions;
}
void Shell::bring_cursor_to_beginning_of_a_line() const
{
struct winsize ws;
if (m_editor) {
ws = m_editor->terminal_size();
} else {
if (ioctl(STDERR_FILENO, TIOCGWINSZ, &ws) < 0) {
// Very annoying assumptions.
ws.ws_col = 80;
ws.ws_row = 25;
}
}
// Black with Cyan background.
constexpr auto default_mark = "\e[30;46m%\e[0m";
String eol_mark = getenv("PROMPT_EOL_MARK");
if (eol_mark.is_null())
eol_mark = default_mark;
size_t eol_mark_length = Line::Editor::actual_rendered_string_metrics(eol_mark).line_lengths.last();
if (eol_mark_length >= ws.ws_col) {
eol_mark = default_mark;
eol_mark_length = 1;
}
fputs(eol_mark.characters(), stderr);
for (auto i = eol_mark_length; i < ws.ws_col; ++i)
putc(' ', stderr);
putc('\r', stderr);
}
bool Shell::read_single_line()
{
restore_ios();
bring_cursor_to_beginning_of_a_line();
auto line_result = m_editor->get_line(prompt());
if (line_result.is_error()) {
if (line_result.error() == Line::Editor::Error::Eof || line_result.error() == Line::Editor::Error::Empty) {
// Pretend the user tried to execute builtin_exit()
run_command("exit");
return read_single_line();
} else {
Core::EventLoop::current().quit(1);
return false;
}
}
auto& line = line_result.value();
if (line.is_empty())
return true;
run_command(line);
m_editor->add_to_history(line);
return true;
}
void Shell::custom_event(Core::CustomEvent& event)
{
if (event.custom_type() == ReadLine) {
if (read_single_line())
Core::EventLoop::current().post_event(*this, make<Core::CustomEvent>(ShellEventType::ReadLine));
return;
}
}
void Shell::notify_child_event()
{
#ifdef ENSURE_WAITID_ONCE
static HashTable<pid_t> s_waited_for_pids;
#endif
Vector<u64> disowned_jobs;
// Workaround the fact that we can't receive *who* exactly changed state.
// The child might still be alive (and even running) when this signal is dispatched to us
// so just...repeat until we find a suitable child.
// This, of course, will mean that someone can send us a SIGCHILD and we'd be spinning here
// until the next child event we can actually handle.
bool found_child = false;
do {
// Ignore stray SIGCHLD when there are no jobs.
if (jobs.is_empty())
return;
for (auto& it : jobs) {
auto job_id = it.key;
auto& job = *it.value;
#ifdef ENSURE_WAITID_ONCE
// Theoretically, this should never trip, as jobs are removed from
// the job table when waitpid() succeeds *and* the child is dead.
ASSERT(!s_waited_for_pids.contains(job.pid()));
#endif
int wstatus = 0;
#ifdef SH_DEBUG
dbgln("waitpid({}) = ...", job.pid());
#endif
auto child_pid = waitpid(job.pid(), &wstatus, WNOHANG | WUNTRACED);
#ifdef SH_DEBUG
dbgln("... = {} - {}", child_pid, wstatus);
#endif
if (child_pid < 0) {
if (errno == ECHILD) {
// The child process went away before we could process its death, just assume it exited all ok.
// FIXME: This should never happen, the child should stay around until we do the waitpid above.
dbgln("Child process gone, cannot get exit code for {}", job_id);
child_pid = job.pid();
} else {
ASSERT_NOT_REACHED();
}
}
if (child_pid == 0) {
// If the child existed, but wasn't dead.
continue;
}
if (child_pid == job.pid()) {
if (WIFSIGNALED(wstatus) && !WIFSTOPPED(wstatus)) {
job.set_signalled(WTERMSIG(wstatus));
} else if (WIFEXITED(wstatus)) {
job.set_has_exit(WEXITSTATUS(wstatus));
} else if (WIFSTOPPED(wstatus)) {
job.unblock();
job.set_is_suspended(true);
}
found_child = true;
#ifdef ENSURE_WAITID_ONCE
// NOTE: This check is here to find bugs about our assumptions about waitpid(),
// it does not hold in general, and it definitely does not hold in the long run.
// Reasons that we would call waitpid() more than once:
// - PID reuse/wraparound: This will simply fail the assertion, ignored here.
// - Non-terminating unblocks:
// - Suspension: (e.g. via ^Z)
// - ?
// - ?
if (job.exited())
s_waited_for_pids.set(child_pid);
#endif
}
if (job.should_be_disowned())
disowned_jobs.append(job_id);
}
for (auto job_id : disowned_jobs) {
jobs.remove(job_id);
}
} while (!found_child);
}
Shell::Shell()
: m_default_constructed(true)
{
push_frame("main").leak_frame();
int rc = gethostname(hostname, Shell::HostNameSize);
if (rc < 0)
perror("gethostname");
{
auto* pw = getpwuid(getuid());
if (pw) {
username = pw->pw_name;
home = pw->pw_dir;
setenv("HOME", pw->pw_dir, 1);
}
endpwent();
}
// For simplicity, start at the user's home directory.
this->cwd = home;
setenv("PWD", home.characters(), 1);
// Add the default PATH vars.
{
StringBuilder path;
path.append(getenv("PATH"));
if (path.length())
path.append(":");
path.append("/bin:/usr/bin:/usr/local/bin");
setenv("PATH", path.to_string().characters(), true);
}
cache_path();
}
Shell::Shell(Line::Editor& editor)
: m_editor(editor)
{
uid = getuid();
tcsetpgrp(0, getpgrp());
m_pid = getpid();
push_frame("main").leak_frame();
int rc = gethostname(hostname, Shell::HostNameSize);
if (rc < 0)
perror("gethostname");
auto istty = isatty(STDIN_FILENO);
m_is_interactive = istty;
if (istty) {
rc = ttyname_r(0, ttyname, Shell::TTYNameSize);
if (rc < 0)
perror("ttyname_r");
} else {
ttyname[0] = 0;
}
{
auto* cwd = getcwd(nullptr, 0);
this->cwd = cwd;
setenv("PWD", cwd, 1);
free(cwd);
}
{
auto* pw = getpwuid(getuid());
if (pw) {
username = pw->pw_name;
home = pw->pw_dir;
setenv("HOME", pw->pw_dir, 1);
}
endpwent();
}
directory_stack.append(cwd);
m_editor->load_history(get_history_path());
cache_path();
m_editor->register_key_input_callback('\n', [](Line::Editor& editor) {
auto ast = Parser(editor.line()).parse();
if (ast && ast->is_syntax_error() && ast->syntax_error_node().is_continuable())
return true;
return EDITOR_INTERNAL_FUNCTION(finish)(editor);
});
}
Shell::~Shell()
{
if (m_default_constructed)
return;
stop_all_jobs();
m_editor->save_history(get_history_path());
}
void Shell::stop_all_jobs()
{
if (!jobs.is_empty()) {
if (m_is_interactive && !m_is_subshell)
printf("Killing active jobs\n");
for (auto& entry : jobs) {
if (entry.value->is_suspended()) {
#ifdef SH_DEBUG
dbgln("Job {} is suspended", entry.value->pid());
#endif
kill_job(entry.value, SIGCONT);
}
kill_job(entry.value, SIGHUP);
}
usleep(10000); // Wait for a bit before killing the job
for (auto& entry : jobs) {
#ifdef SH_DEBUG
dbgln("Actively killing {} ({})", entry.value->pid(), entry.value->cmd());
#endif
kill_job(entry.value, SIGKILL);
}
jobs.clear();
}
}
u64 Shell::find_last_job_id() const
{
u64 job_id = 0;
for (auto& entry : jobs) {
if (entry.value->job_id() > job_id)
job_id = entry.value->job_id();
}
return job_id;
}
const Job* Shell::find_job(u64 id)
{
for (auto& entry : jobs) {
if (entry.value->job_id() == id)
return entry.value;
}
return nullptr;
}
void Shell::kill_job(const Job* job, int sig)
{
if (!job)
return;
if (killpg(job->pgid(), sig) < 0) {
if (kill(job->pid(), sig) < 0) {
perror("kill");
}
}
}
void Shell::save_to(JsonObject& object)
{
Core::Object::save_to(object);
object.set("working_directory", cwd);
object.set("username", username);
object.set("user_home_path", home);
object.set("user_id", uid);
object.set("directory_stack_size", directory_stack.size());
object.set("cd_history_size", cd_history.size());
// Jobs.
JsonArray job_objects;
for (auto& job_entry : jobs) {
JsonObject job_object;
job_object.set("pid", job_entry.value->pid());
job_object.set("pgid", job_entry.value->pgid());
job_object.set("running_time", job_entry.value->timer().elapsed());
job_object.set("command", job_entry.value->cmd());
job_object.set("is_running_in_background", job_entry.value->is_running_in_background());
job_objects.append(move(job_object));
}
object.set("jobs", move(job_objects));
}
void FileDescriptionCollector::collect()
{
for (auto fd : m_fds)
close(fd);
m_fds.clear();
}
FileDescriptionCollector::~FileDescriptionCollector()
{
collect();
}
void FileDescriptionCollector::add(int fd)
{
m_fds.append(fd);
}
SavedFileDescriptors::SavedFileDescriptors(const NonnullRefPtrVector<AST::Rewiring>& intended_rewirings)
{
for (auto& rewiring : intended_rewirings) {
int new_fd = dup(rewiring.new_fd);
if (new_fd < 0) {
if (errno != EBADF)
perror("dup");
// The fd that will be overwritten isn't open right now,
// it will be cleaned up by the exec()-side collector
// and we have nothing to do here, so just ignore this error.
continue;
}
auto flags = fcntl(new_fd, F_GETFL);
auto rc = fcntl(new_fd, F_SETFL, flags | FD_CLOEXEC);
ASSERT(rc == 0);
m_saves.append({ rewiring.new_fd, new_fd });
m_collector.add(new_fd);
}
}
SavedFileDescriptors::~SavedFileDescriptors()
{
for (auto& save : m_saves) {
if (dup2(save.saved, save.original) < 0) {
perror("dup2(~SavedFileDescriptors)");
continue;
}
}
}
}