Kernel: Add partial support for shell

We don't handle arrow keys, and the tty does not know how to clear
the screeen :D

kernel/include/kernel/Shell.h

@@ -19,10 +19,9 @@ namespace Kernel
 		void rerender_buffer() const;
 		BAN::Vector<BAN::String> parse_arguments(BAN::StringView) const;
 		BAN::ErrorOr<void> process_command(const BAN::Vector<BAN::String>&);
-		void key_event_callback(Input::KeyEvent);
 		BAN::ErrorOr<void> update_prompt();
 
-	private:		
+	private:
 		BAN::Vector<BAN::String>	m_old_buffer;
 		BAN::Vector<BAN::String>	m_buffer;
 		BAN::String					m_prompt_string;

kernel/include/kernel/Terminal/TTY.h

@@ -39,6 +39,7 @@ namespace Kernel
 		void render_from_buffer(uint32_t x, uint32_t y);
 
 		void on_key(Input::KeyEvent);
+		void do_backspace();
 
 	private:
 		enum class State

kernel/kernel/Shell.cpp

@@ -11,11 +11,23 @@
 #include <kernel/RTC.h>
 #include <kernel/Shell.h>
 
-#include <fcntl.h>
 #include <ctype.h>
+#include <fcntl.h>
+#include <unistd.h>
+
+#define TTY_PRINT(...) \
+	do { \
+		BAN::String message_ = BAN::String::formatted(__VA_ARGS__); \
+		MUST(Process::current()->write(STDOUT_FILENO, message_.data(), message_.size())); \
+	} while (false)
+
+#define TTY_PRINTLN(...) \
+	do { \
+		TTY_PRINT(__VA_ARGS__); \
+		MUST(Process::current()->write(STDOUT_FILENO, "\n", 1)); \
+	} while (false)
+
 
-#define TTY_PRINT(...)
-#define TTY_PRINTLN(...)
 
 namespace Kernel
 {
@@ -99,17 +111,22 @@ namespace Kernel
 
 	void Shell::run()
 	{
-		int fd = MUST(Process::current()->open("/dev/tty1"sv, O_RDONLY));
-
 		TTY_PRINT("{}", m_prompt);
+		BAN::String input;
 		for (;;)
 		{
-			uint8_t buffer[128];
+			char buffer[128];
-			size_t n_read = MUST(Process::current()->read(fd, buffer, sizeof(buffer)));
+			size_t n_read = MUST(Process::current()->read(STDIN_FILENO, buffer, sizeof(buffer)));
-			dprintln("{}", BAN::StringView((const char*)buffer, n_read));
+
-			//Input::KeyEvent event;
+			MUST(input.append(BAN::StringView(buffer, n_read)));
-			//MUST(Process::current()->read(fd, &event, sizeof(event)));
+			if (input.back() == '\n')
-			//key_event_callback(event);
+			{
+				input.pop_back();
+				if (auto res = process_command(parse_arguments(input)); res.is_error())
+					TTY_PRINTLN("{}", res.error());
+				TTY_PRINT("{}", m_prompt);
+				input.clear();
+			}
 		}
 	}
 
@@ -540,147 +557,4 @@ argument_done:
 		TTY_PRINT("\e[{}G{}\e[K", m_prompt_length + 1, m_buffer[m_cursor_pos.line]);
 	}
 
-	static uint32_t get_last_length(BAN::StringView sv)
-	{
-		if (sv.size() >= 2 && ((uint8_t)sv[sv.size() - 2] >> 5) == 0b110)	return 2;
-		if (sv.size() >= 3 && ((uint8_t)sv[sv.size() - 3] >> 4) == 0b1110)	return 3;
-		if (sv.size() >= 4 && ((uint8_t)sv[sv.size() - 4] >> 3) == 0b11110)	return 4;
-		return BAN::Math::min<uint32_t>(sv.size(), 1);
-	}
-
-	static uint32_t get_next_length(BAN::StringView sv)
-	{
-		if (sv.size() >= 2 && ((uint8_t)sv[0] >> 5) == 0b110)	return 2;
-		if (sv.size() >= 3 && ((uint8_t)sv[0] >> 4) == 0b1110)	return 3;
-		if (sv.size() >= 4 && ((uint8_t)sv[0] >> 3) == 0b11110)	return 4;
-		return BAN::Math::min<uint32_t>(sv.size(), 1);
-	}
-
-	static uint32_t get_unicode_character_count(BAN::StringView sv)
-	{
-		uint32_t len = 0;
-		for (uint32_t i = 0; i < sv.size(); i++)
-		{
-			uint8_t ch = sv[i];
-			if ((ch >> 5) == 0b110)		i += 1;
-			if ((ch >> 4) == 0b1110)	i += 2;
-			if ((ch >> 3) == 0b11110)	i += 3;
-			len++;
-		}
-		return len;
-	}
-
-	void Shell::key_event_callback(Input::KeyEvent event)
-	{
-		if (event.released())
-			return;
-
-		BAN::String& current_buffer = m_buffer[m_cursor_pos.line];
-
-		switch (event.key)
-		{
-			case Input::Key::Backspace:
-				if (m_cursor_pos.col > 0)
-				{
-					TTY_PRINT("\e[D{} ", current_buffer.sv().substring(m_cursor_pos.index));
-					
-					uint32_t len = get_last_length(current_buffer.sv().substring(0, m_cursor_pos.index));
-					m_cursor_pos.index -= len;
-					current_buffer.erase(m_cursor_pos.index, len);
-					m_cursor_pos.col--;
-				}
-				break;
-
-			case Input::Key::Enter:
-			case Input::Key::NumpadEnter:
-			{
-				TTY_PRINTLN("");
-				auto arguments = parse_arguments(current_buffer.sv());
-				if (!arguments.empty())
-				{
-					if (auto res = process_command(arguments); res.is_error())
-						TTY_PRINTLN("{}", res.error());
-					MUST(m_old_buffer.push_back(current_buffer));
-					m_buffer = m_old_buffer;
-					MUST(m_buffer.push_back(""sv));
-					m_cursor_pos.line = m_buffer.size() - 1;
-				}
-				m_cursor_pos.col = 0;
-				m_cursor_pos.index = 0;
-				TTY_PRINT("{}", m_prompt);
-				break;
-			}
-
-			case Input::Key::Escape:
-				TTY_PRINTLN("time since boot {} ms", PIT::ms_since_boot());
-				break;
-
-			case Input::Key::Tab:
-				break;
-			
-			case Input::Key::ArrowLeft:
-				if (m_cursor_pos.index > 0)
-				{					
-					uint32_t len = get_last_length(current_buffer.sv().substring(0, m_cursor_pos.index));
-					m_cursor_pos.index -= len;
-					m_cursor_pos.col--;
-				}
-				break;
-
-			case Input::Key::ArrowRight:
-				if (m_cursor_pos.index < current_buffer.size())
-				{
-					uint32_t len = get_next_length(current_buffer.sv().substring(m_cursor_pos.index));
-					m_cursor_pos.index += len;
-					m_cursor_pos.col++;
-				}
-				break;
-
-			case Input::Key::ArrowUp:
-				if (m_cursor_pos.line > 0)
-				{
-					const auto& new_buffer = m_buffer[m_cursor_pos.line - 1];
-					m_cursor_pos.line--;
-					m_cursor_pos.index = new_buffer.size();
-					m_cursor_pos.col = get_unicode_character_count(new_buffer);
-					rerender_buffer();
-				}
-				break;
-
-			case Input::Key::ArrowDown:
-				if (m_cursor_pos.line < m_buffer.size() - 1)
-				{
-					const auto& new_buffer = m_buffer[m_cursor_pos.line + 1];
-					m_cursor_pos.line++;
-					m_cursor_pos.index = new_buffer.size();
-					m_cursor_pos.col = get_unicode_character_count(new_buffer);
-					rerender_buffer();
-				}
-				break;
-
-			case Input::Key::A:
-				if (event.ctrl())
-				{
-					m_cursor_pos.col = m_cursor_pos.index = 0;
-					break;
-				}
-				// fall through
-
-			default:
-			{
-				const char* utf8 = Input::key_event_to_utf8(event);
-				if (utf8)
-				{
-					TTY_PRINT("{}{}", utf8, current_buffer.sv().substring(m_cursor_pos.index));
-					MUST(current_buffer.insert(utf8, m_cursor_pos.index));
-					m_cursor_pos.index += strlen(utf8);
-					m_cursor_pos.col++;
-				}
-				break;
-			}
-		}
-
-		//TTY_PRINT("\e[{}G", (m_prompt_length + m_cursor_pos.col) % m_tty->width() + 1);
-	}
-
 }

kernel/kernel/Terminal/TTY.cpp

@@ -92,6 +92,7 @@ namespace Kernel
 					ansi = "\n";
 					break;
 				case Input::Key::Backspace:
+					ansi = nullptr;
 					if (m_output.bytes > 0)
 					{
 						// Multibyte UTF8
@@ -103,19 +104,20 @@ namespace Kernel
 								ASSERT(m_output.bytes > 0);
 								m_output.bytes--;
 							}
-							ansi = "\b \b";
+							do_backspace();
 						}
 						// Control sequence
 						else if (m_output.bytes >= 2 && m_output.buffer[m_output.bytes - 2] == '\e')
 						{
 							m_output.bytes -= 2;
-							ansi = "\b\b  \b\b";
+							do_backspace();
+							do_backspace();
 						}
 						// Ascii
 						else
 						{
 							m_output.bytes--;
-							ansi = "\b \b";
+							do_backspace();
 						}
 					}
 					break;
@@ -156,6 +158,16 @@ namespace Kernel
 		m_terminal_driver->clear(m_background);
 	}
 
+	void TTY::do_backspace()
+	{
+		if (m_column > 0)
+		{
+			m_column--;
+			putchar_at(' ', m_column, m_row);
+			set_cursor_position(m_column, m_row);
+		}
+	}
+
 	void TTY::set_cursor_position(uint32_t x, uint32_t y)
 	{
 		static uint32_t last_x = -1;

kernel/kernel/kernel.cpp

@@ -222,25 +222,10 @@ static void init2(void* terminal_driver)
 	ASSERT(tty1);
 	DeviceManager::get().add_device(tty1);
 
-	MUST(Process::create_kernel(
-		[](void*)
-		{
-			MUST(Process::current()->init_stdio());
-			while (true)
-			{
-				char buffer[1024];
-				int n_read = MUST(Process::current()->read(STDIN_FILENO, buffer, sizeof(buffer)));
-				MUST(Process::current()->write(STDOUT_FILENO, buffer, n_read));
-				dprintln("{} bytes", n_read);
-			}
-		}, nullptr
-	));
-
-	return;
-
 	MUST(Process::create_kernel(
 		[](void*) 
 		{
+			MUST(Process::current()->init_stdio());
 			Shell* shell = new Shell();
 			ASSERT(shell);
 			shell->run();