ladybird/Shell/Shell.h
William Marlow 96cd04f2ba Shell: Implement a very basic exec builtin
Other shells also support a number of other options with exec and
some have special behaviour when calling exec with no arguments except
redirections.

This PR only supports the basic case of replacing the Shell process
(or LibShell host process) with the provided command.
2020-12-30 02:13:53 +01:00

311 lines
10 KiB
C++

/*
* 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.
*/
#pragma once
#include "Job.h"
#include "Parser.h"
#include <AK/CircularQueue.h>
#include <AK/HashMap.h>
#include <AK/NonnullOwnPtrVector.h>
#include <AK/String.h>
#include <AK/StringBuilder.h>
#include <AK/Types.h>
#include <AK/Vector.h>
#include <LibCore/Notifier.h>
#include <LibCore/Object.h>
#include <LibLine/Editor.h>
#include <termios.h>
#define ENUMERATE_SHELL_BUILTINS() \
__ENUMERATE_SHELL_BUILTIN(alias) \
__ENUMERATE_SHELL_BUILTIN(cd) \
__ENUMERATE_SHELL_BUILTIN(cdh) \
__ENUMERATE_SHELL_BUILTIN(pwd) \
__ENUMERATE_SHELL_BUILTIN(exec) \
__ENUMERATE_SHELL_BUILTIN(exit) \
__ENUMERATE_SHELL_BUILTIN(export) \
__ENUMERATE_SHELL_BUILTIN(glob) \
__ENUMERATE_SHELL_BUILTIN(unset) \
__ENUMERATE_SHELL_BUILTIN(history) \
__ENUMERATE_SHELL_BUILTIN(umask) \
__ENUMERATE_SHELL_BUILTIN(dirs) \
__ENUMERATE_SHELL_BUILTIN(pushd) \
__ENUMERATE_SHELL_BUILTIN(popd) \
__ENUMERATE_SHELL_BUILTIN(setopt) \
__ENUMERATE_SHELL_BUILTIN(shift) \
__ENUMERATE_SHELL_BUILTIN(time) \
__ENUMERATE_SHELL_BUILTIN(jobs) \
__ENUMERATE_SHELL_BUILTIN(disown) \
__ENUMERATE_SHELL_BUILTIN(fg) \
__ENUMERATE_SHELL_BUILTIN(bg) \
__ENUMERATE_SHELL_BUILTIN(wait)
#define ENUMERATE_SHELL_OPTIONS() \
__ENUMERATE_SHELL_OPTION(inline_exec_keep_empty_segments, false, "Keep empty segments in inline execute $(...)") \
__ENUMERATE_SHELL_OPTION(verbose, false, "Announce every command that is about to be executed")
namespace Shell {
class Shell;
class Shell : public Core::Object {
C_OBJECT(Shell);
public:
constexpr static auto local_init_file_path = "~/.shellrc";
constexpr static auto global_init_file_path = "/etc/shellrc";
bool should_format_live() const { return m_should_format_live; }
void set_live_formatting(bool value) { m_should_format_live = value; }
void setup_signals();
int run_command(const StringView&);
bool is_runnable(const StringView&);
RefPtr<Job> run_command(const AST::Command&);
NonnullRefPtrVector<Job> run_commands(Vector<AST::Command>&);
bool run_file(const String&, bool explicitly_invoked = true);
bool run_builtin(const AST::Command&, const NonnullRefPtrVector<AST::Rewiring>&, int& retval);
bool has_builtin(const StringView&) const;
void block_on_job(RefPtr<Job>);
void block_on_pipeline(RefPtr<AST::Pipeline>);
String prompt() const;
static String expand_tilde(const String&);
static Vector<String> expand_globs(const StringView& path, StringView base);
static Vector<String> expand_globs(Vector<StringView> path_segments, const StringView& base);
Vector<AST::Command> expand_aliases(Vector<AST::Command>);
String resolve_path(String) const;
String resolve_alias(const String&) const;
RefPtr<AST::Value> get_argument(size_t);
RefPtr<AST::Value> lookup_local_variable(const String&);
String local_variable_or(const String&, const String&);
void set_local_variable(const String&, RefPtr<AST::Value>, bool only_in_current_frame = false);
void unset_local_variable(const String&, bool only_in_current_frame = false);
void define_function(String name, Vector<String> argnames, RefPtr<AST::Node> body);
bool has_function(const String&);
bool invoke_function(const AST::Command&, int& retval);
String format(const StringView&, ssize_t& cursor) const;
RefPtr<Line::Editor> editor() const { return m_editor; }
struct LocalFrame {
LocalFrame(const String& name, HashMap<String, RefPtr<AST::Value>> variables)
: name(name)
, local_variables(move(variables))
{
}
String name;
HashMap<String, RefPtr<AST::Value>> local_variables;
};
struct Frame {
Frame(NonnullOwnPtrVector<LocalFrame>& frames, const LocalFrame& frame)
: frames(frames)
, frame(frame)
{
}
~Frame();
void leak_frame() { should_destroy_frame = false; }
private:
NonnullOwnPtrVector<LocalFrame>& frames;
const LocalFrame& frame;
bool should_destroy_frame { true };
};
[[nodiscard]] Frame push_frame(String name);
void pop_frame();
static String escape_token(const String& token);
static String unescape_token(const String& token);
static bool is_glob(const StringView&);
static Vector<StringView> split_path(const StringView&);
void highlight(Line::Editor&) const;
Vector<Line::CompletionSuggestion> complete();
Vector<Line::CompletionSuggestion> complete_path(const String& base, const String&, size_t offset);
Vector<Line::CompletionSuggestion> complete_program_name(const String&, size_t offset);
Vector<Line::CompletionSuggestion> complete_variable(const String&, size_t offset);
Vector<Line::CompletionSuggestion> complete_user(const String&, size_t offset);
Vector<Line::CompletionSuggestion> complete_option(const String&, const String&, size_t offset);
void restore_ios();
u64 find_last_job_id() const;
const Job* find_job(u64 id);
const Job* current_job() const { return m_current_job; }
void kill_job(const Job*, int sig);
String get_history_path();
void print_path(const String& path);
bool read_single_line();
void notify_child_event();
struct termios termios;
struct termios default_termios;
bool was_interrupted { false };
bool was_resized { false };
String cwd;
String username;
String home;
constexpr static auto TTYNameSize = 32;
constexpr static auto HostNameSize = 64;
char ttyname[TTYNameSize];
char hostname[HostNameSize];
uid_t uid;
int last_return_code { 0 };
Vector<String> directory_stack;
CircularQueue<String, 8> cd_history; // FIXME: have a configurable cd history length
HashMap<u64, NonnullRefPtr<Job>> jobs;
Vector<String, 256> cached_path;
String current_script;
enum ShellEventType {
ReadLine,
};
enum class ShellError {
None,
InternalControlFlowBreak,
InternalControlFlowContinue,
EvaluatedSyntaxError,
NonExhaustiveMatchRules,
InvalidGlobError,
};
void raise_error(ShellError kind, String description)
{
m_error = kind;
m_error_description = move(description);
}
bool has_error(ShellError err) const { return m_error == err; }
const String& error_description() const { return m_error_description; }
ShellError take_error()
{
auto err = m_error;
m_error = ShellError::None;
m_error_description = {};
return err;
}
void possibly_print_error() const;
#define __ENUMERATE_SHELL_OPTION(name, default_, description) \
bool name { default_ };
struct Options {
ENUMERATE_SHELL_OPTIONS();
} options;
#undef __ENUMERATE_SHELL_OPTION
private:
Shell(Line::Editor&);
Shell();
virtual ~Shell() override;
// FIXME: Port to Core::Property
void save_to(JsonObject&);
void bring_cursor_to_beginning_of_a_line() const;
void cache_path();
void add_entry_to_cache(const String&);
void stop_all_jobs();
const Job* m_current_job { nullptr };
LocalFrame* find_frame_containing_local_variable(const String& name);
void run_tail(RefPtr<Job>);
void run_tail(const AST::Command&, const AST::NodeWithAction&, int head_exit_code);
[[noreturn]] void execute_process(Vector<const char*>&& argv);
virtual void custom_event(Core::CustomEvent&) override;
#define __ENUMERATE_SHELL_BUILTIN(builtin) \
int builtin_##builtin(int argc, const char** argv);
ENUMERATE_SHELL_BUILTINS();
#undef __ENUMERATE_SHELL_BUILTIN
constexpr static const char* builtin_names[] = {
#define __ENUMERATE_SHELL_BUILTIN(builtin) #builtin,
ENUMERATE_SHELL_BUILTINS()
#undef __ENUMERATE_SHELL_BUILTIN
};
bool m_should_ignore_jobs_on_next_exit { false };
pid_t m_pid { 0 };
struct ShellFunction {
String name;
Vector<String> arguments;
RefPtr<AST::Node> body;
};
HashMap<String, ShellFunction> m_functions;
NonnullOwnPtrVector<LocalFrame> m_local_frames;
NonnullRefPtrVector<AST::Redirection> m_global_redirections;
HashMap<String, String> m_aliases;
bool m_is_interactive { true };
bool m_is_subshell { false };
bool m_should_reinstall_signal_handlers { true };
ShellError m_error { ShellError::None };
String m_error_description;
bool m_should_format_live { false };
RefPtr<Line::Editor> m_editor;
bool m_default_constructed { false };
mutable bool m_last_continuation_state { false }; // false == not needed.
};
static constexpr bool is_word_character(char c)
{
return c == '_' || (c <= 'Z' && c >= 'A') || (c <= 'z' && c >= 'a');
}
}