Kernel/Shell: Add support for delete key

Test should be programs in /bin instead

BAN/include/BAN/Vector.h

@@ -7,6 +7,7 @@
 #include <BAN/New.h>
 #include <BAN/PlacementNew.h>
 #include <BAN/Span.h>
+#include <BAN/Swap.h>
 
 namespace BAN
 {
@@ -65,6 +66,8 @@ namespace BAN
 		const T& front() const;
 		T& front();
 
+		void reverse();
+
 		ErrorOr<void> resize(size_type)				requires is_default_constructible_v<T>;
 		ErrorOr<void> resize(size_type, const T&)	requires is_copy_constructible_v<T>;
 		ErrorOr<void> reserve(size_type);
@@ -301,6 +304,13 @@ namespace BAN
 		return m_data[0];
 	}
 
+	template<typename T>
+	void Vector<T>::reverse()
+	{
+		for (size_type i = 0; i < m_size / 2; i++)
+			BAN::swap(m_data[i], m_data[m_size - i - 1]);
+	}
+
 	template<typename T>
 	ErrorOr<void> Vector<T>::resize(size_type size) requires is_default_constructible_v<T>
 	{

kernel/include/kernel/ACPI/AML/Names.h

@@ -215,8 +215,10 @@ namespace BAN
 		}
 	};
 
+	namespace Formatter
+	{
 		template<typename F>
-	void Formatter::print_argument(F putc, const Kernel::ACPI::AML::NameSeg& name_seg, const ValueFormat&)
+		void print_argument(F putc, const Kernel::ACPI::AML::NameSeg& name_seg, const ValueFormat&)
 		{
 			size_t len = 4;
 			while (len > 0 && name_seg.chars[len - 1] == '_')
@@ -226,7 +228,7 @@ namespace BAN
 		}
 
 		template<typename F>
-	void Formatter::print_argument(F putc, const Kernel::ACPI::AML::NameString& name_string, const ValueFormat&)
+		void print_argument(F putc, const Kernel::ACPI::AML::NameString& name_string, const ValueFormat&)
 		{
 			print_argument(putc, name_string.prefix, {});
 			if (!name_string.path.empty())
@@ -237,5 +239,6 @@ namespace BAN
 				print_argument(putc, name_string.path[i], {});
 			}
 		}
+	}
 
 }

kernel/include/kernel/FS/Inode.h

@@ -64,7 +64,7 @@ namespace Kernel
 	public:
 		virtual ~Inode() {}
 
-		bool can_access(const Credentials&, int);
+		bool can_access(const Credentials&, int) const;
 
 		bool operator==(const Inode& other) const { return dev() == other.dev() && ino() == other.ino(); }
 

kernel/include/kernel/FS/VirtualFileSystem.h

@@ -24,10 +24,51 @@ namespace Kernel
 
 		struct File
 		{
+			File() = default;
+			explicit File(BAN::RefPtr<Inode> inode)
+				: inode(BAN::move(inode))
+			{ }
+			explicit File(BAN::RefPtr<Inode> inode, BAN::String&& canonical_path)
+				: inode(BAN::move(inode))
+				, canonical_path(BAN::move(canonical_path))
+			{ }
+
+			File(const File&) = delete;
+			File(File&& other)
+				: inode(BAN::move(other.inode))
+				, canonical_path(BAN::move(other.canonical_path))
+			{ }
+
+			File& operator=(const File&) = delete;
+			File& operator=(File&& other)
+			{
+				inode = BAN::move(other.inode);
+				canonical_path = BAN::move(other.canonical_path);
+				return *this;
+			}
+
+			BAN::ErrorOr<File> clone() const
+			{
+				File result;
+				result.inode = inode;
+				TRY(result.canonical_path.append(canonical_path));
+				return BAN::move(result);
+			}
+
 			BAN::RefPtr<Inode> inode;
 			BAN::String canonical_path;
 		};
-		BAN::ErrorOr<File> file_from_absolute_path(const Credentials&, BAN::StringView, int);
+
+		File root_file()
+		{
+			return File(root_inode(), "/"_sv);
+		}
+
+		BAN::ErrorOr<File> file_from_relative_path(const File& parent, const Credentials&, BAN::StringView, int);
+		BAN::ErrorOr<File> file_from_absolute_path(const Credentials& credentials, BAN::StringView path, int flags)
+		{
+			return file_from_relative_path(File(root_inode()), credentials, path, flags);
+		}
 
 	private:
 		VirtualFileSystem() = default;

kernel/include/kernel/OpenFileDescriptorSet.h

@@ -39,10 +39,6 @@ namespace Kernel
 
 		BAN::ErrorOr<void> truncate(int fd, off_t length);
 
-		BAN::ErrorOr<void> fstat(int fd, struct stat*) const;
-		BAN::ErrorOr<void> fstatat(int fd, BAN::StringView path, struct stat* buf, int flag);
-		BAN::ErrorOr<void> stat(BAN::StringView absolute_path, struct stat* buf, int flag);
-
 		BAN::ErrorOr<void> close(int);
 		void close_all();
 		void close_cloexec();
@@ -52,6 +48,7 @@ namespace Kernel
 
 		BAN::ErrorOr<size_t> read_dir_entries(int fd, struct dirent* list, size_t list_len);
 
+		BAN::ErrorOr<VirtualFileSystem::File> file_of(int) const;
 		BAN::ErrorOr<BAN::StringView> path_of(int) const;
 		BAN::ErrorOr<BAN::RefPtr<Inode>> inode_of(int);
 		BAN::ErrorOr<int> flags_of(int) const;
@@ -59,15 +56,16 @@ namespace Kernel
 	private:
 		struct OpenFileDescription : public BAN::RefCounted<OpenFileDescription>
 		{
-			OpenFileDescription(BAN::RefPtr<Inode> inode, BAN::String path, off_t offset, int flags)
-				: inode(inode)
-				, path(BAN::move(path))
+			OpenFileDescription(VirtualFileSystem::File file, off_t offset, int flags)
+				: file(BAN::move(file))
 				, offset(offset)
 				, flags(flags)
 			{ }
 
-			BAN::RefPtr<Inode> inode;
-			BAN::String path;
+			BAN::RefPtr<Inode> inode() const { return file.inode; }
+			BAN::StringView path() const { return file.canonical_path.sv(); }
+
+			VirtualFileSystem::File file;
 			off_t offset { 0 };
 			int flags { 0 };
 

kernel/include/kernel/Process.h

@@ -101,10 +101,10 @@ namespace Kernel
 
 		BAN::ErrorOr<long> sys_getpid() const { return pid(); }
 
-		BAN::ErrorOr<long> open_inode(BAN::RefPtr<Inode>, int flags);
+		BAN::ErrorOr<long> open_inode(VirtualFileSystem::File&&, int flags);
 
-		BAN::ErrorOr<void> create_file_or_dir(BAN::StringView name, mode_t mode);
-		BAN::ErrorOr<long> open_file(BAN::StringView path, int oflag, mode_t = 0);
+		BAN::ErrorOr<void> create_file_or_dir(const VirtualFileSystem::File& parent, BAN::StringView path, mode_t mode) const;
+		BAN::ErrorOr<long> open_file_impl(const VirtualFileSystem::File& parent, BAN::StringView path, int oflag, mode_t = 0);
 		BAN::ErrorOr<long> sys_open(const char* path, int, mode_t);
 		BAN::ErrorOr<long> sys_openat(int, const char* path, int, mode_t);
 		BAN::ErrorOr<long> sys_close(int fd);
@@ -114,7 +114,7 @@ namespace Kernel
 		BAN::ErrorOr<long> sys_create(const char*, mode_t);
 		BAN::ErrorOr<long> sys_create_dir(const char*, mode_t);
 		BAN::ErrorOr<long> sys_unlink(const char*);
-		BAN::ErrorOr<long> readlink_impl(BAN::StringView absolute_path, char* buffer, size_t bufsize);
+		BAN::ErrorOr<long> readlink_impl(BAN::RefPtr<Inode>, char* buffer, size_t bufsize);
 		BAN::ErrorOr<long> sys_readlink(const char* path, char* buffer, size_t bufsize);
 		BAN::ErrorOr<long> sys_readlinkat(int fd, const char* path, char* buffer, size_t bufsize);
 
@@ -217,13 +217,12 @@ namespace Kernel
 		// ONLY CALLED BY TIMER INTERRUPT
 		static void update_alarm_queue();
 
+		const VirtualFileSystem::File& working_directory() const { return m_working_directory; }
+
 	private:
 		Process(const Credentials&, pid_t pid, pid_t parent, pid_t sid, pid_t pgrp);
 		static Process* create_process(const Credentials&, pid_t parent, pid_t sid = 0, pid_t pgrp = 0);
 
-		// Load elf from a file
-		static BAN::ErrorOr<BAN::UniqPtr<LibELF::LoadableELF>> load_elf_for_exec(const Credentials&, BAN::StringView file_path, const BAN::String& cwd, Kernel::PageTable&);
-
 		BAN::ErrorOr<void> validate_string_access(const char*);
 		BAN::ErrorOr<void> validate_pointer_access_check(const void*, size_t, bool needs_write);
 		BAN::ErrorOr<void> validate_pointer_access(const void*, size_t, bool needs_write);
@@ -280,7 +279,8 @@ namespace Kernel
 
 		mutable Mutex m_process_lock;
 
-		BAN::String m_working_directory;
+		VirtualFileSystem::File m_working_directory;
+
 		BAN::Vector<Thread*> m_threads;
 
 		uint64_t m_alarm_interval_ns { 0 };

kernel/kernel/FS/Inode.cpp

@@ -6,7 +6,7 @@
 namespace Kernel
 {
 
-	bool Inode::can_access(const Credentials& credentials, int flags)
+	bool Inode::can_access(const Credentials& credentials, int flags) const
 	{
 		if (credentials.is_superuser())
 			return true;

kernel/kernel/FS/VirtualFileSystem.cpp

@@ -105,7 +105,7 @@ namespace Kernel
 			return BAN::Error::from_errno(ENOTDIR);
 
 		LockGuard _(m_mutex);
-		TRY(m_mount_points.push_back({ file_system, file  }));
+		TRY(m_mount_points.emplace_back(file_system, BAN::move(file)));
 		return {};
 	}
 
@@ -127,43 +127,59 @@ namespace Kernel
 		return nullptr;
 	}
 
-	BAN::ErrorOr<VirtualFileSystem::File> VirtualFileSystem::file_from_absolute_path(const Credentials& credentials, BAN::StringView path, int flags)
+	BAN::ErrorOr<VirtualFileSystem::File> VirtualFileSystem::file_from_relative_path(const File& parent, const Credentials& credentials, BAN::StringView path, int flags)
 	{
 		LockGuard _(m_mutex);
 
-		ASSERT(path.front() == '/');
-
-		auto inode = root_inode();
+		auto inode = parent.inode;
 		ASSERT(inode);
 
 		BAN::String canonical_path;
+		TRY(canonical_path.append(parent.canonical_path));
+		if (!canonical_path.empty() && canonical_path.back() == '/')
+			canonical_path.pop_back();
+		ASSERT(canonical_path.empty() || canonical_path.back() != '/');
 
 		BAN::Vector<BAN::String> path_parts;
 
+		const auto append_string_view_in_reverse =
+			[&path_parts](BAN::StringView path) -> BAN::ErrorOr<void>
 			{
-			auto temp = TRY(path.split('/'));
-			for (size_t i = 0; i < temp.size(); i++)
-				TRY(path_parts.emplace_back(temp[temp.size() - i - 1]));
+				auto split_path = TRY(path.split('/'));
+				split_path.reverse();
+				for (auto part : split_path)
+				{
+					TRY(path_parts.emplace_back());
+					TRY(path_parts.back().append(part));
 				}
+				return {};
+			};
+		TRY(append_string_view_in_reverse(path));
 
 		size_t link_depth = 0;
 
 		while (!path_parts.empty())
 		{
-			const auto& path_part = path_parts.back();
-			auto orig = inode;
+			BAN::String path_part = BAN::move(path_parts.back());
+			path_parts.pop_back();
 
 			if (path_part.empty() || path_part == "."_sv)
-			{
+				continue;
 
-			}
-			else if (path_part == ".."_sv)
+			auto orig = inode;
+
+			// resolve file name
 			{
+				auto parent_inode = inode;
+				if (path_part == ".."_sv)
 					if (auto* mount_point = mount_from_root_inode(inode))
-					inode = TRY(mount_point->host.inode->find_inode(".."_sv));
-				else
-					inode = TRY(inode->find_inode(".."_sv));
+						parent_inode = mount_point->host.inode;
+				if (!parent_inode->can_access(credentials, O_SEARCH))
+					return BAN::Error::from_errno(EACCES);
+				inode = TRY(parent_inode->find_inode(path_part));
 
+				if (path_part == ".."_sv)
+				{
 					if (!canonical_path.empty())
 					{
 						ASSERT(canonical_path.front() == '/');
@@ -174,34 +190,28 @@ namespace Kernel
 				}
 				else
 				{
-				if (!inode->can_access(credentials, O_SEARCH))
-					return BAN::Error::from_errno(EACCES);
-
-				inode = TRY(inode->find_inode(path_part));
-
 					if (auto* mount_point = mount_from_host_inode(inode))
 						inode = mount_point->target->root_inode();
-
 					TRY(canonical_path.push_back('/'));
 					TRY(canonical_path.append(path_part));
 				}
+			}
 
-			path_parts.pop_back();
+			if (!inode->mode().iflnk())
+				continue;
+			if ((flags & O_NOFOLLOW) && path_parts.empty())
+				continue;
 
-			if (inode->mode().iflnk() && (!(flags & O_NOFOLLOW) || !path_parts.empty()))
+			// resolve symbolic links
 			{
-				auto target = TRY(inode->link_target());
-				if (target.empty())
+				auto link_target = TRY(inode->link_target());
+				if (link_target.empty())
 					return BAN::Error::from_errno(ENOENT);
 
-				if (target.front() == '/')
+				if (link_target.front() == '/')
 				{
 					inode = root_inode();
 					canonical_path.clear();
-
-					auto temp = TRY(target.sv().split('/'));
-					for (size_t i = 0; i < temp.size(); i++)
-						TRY(path_parts.emplace_back(temp[temp.size() - i - 1]));
 				}
 				else
 				{
@@ -210,12 +220,10 @@ namespace Kernel
 					while (canonical_path.back() != '/')
 						canonical_path.pop_back();
 					canonical_path.pop_back();
-
-					auto new_parts = TRY(target.sv().split('/'));
-					for (size_t i = 0; i < new_parts.size(); i++)
-						TRY(path_parts.emplace_back(new_parts[new_parts.size() - i - 1]));
 				}
 
+				TRY(append_string_view_in_reverse(link_target.sv()));
+
 				link_depth++;
 				if (link_depth > 100)
 					return BAN::Error::from_errno(ELOOP);

kernel/kernel/Networking/TCPSocket.cpp

@@ -123,7 +123,7 @@ namespace Kernel
 			memcpy(address, &connection.target.address, *address_len);
 		}
 
-		return TRY(Process::current().open_inode(return_inode, O_RDWR | flags));
+		return TRY(Process::current().open_inode(VirtualFileSystem::File(return_inode, "<tcp socket>"_sv), O_RDWR | flags));
 	}
 
 	BAN::ErrorOr<void> TCPSocket::connect_impl(const sockaddr* address, socklen_t address_len)

kernel/kernel/Networking/UNIX/Socket.cpp

@@ -104,7 +104,7 @@ namespace Kernel
 			strncpy(sockaddr_un.sun_path, pending->m_bound_path.data(), copy_len);
 		}
 
-		return TRY(Process::current().open_inode(return_inode, O_RDWR | flags));
+		return TRY(Process::current().open_inode(VirtualFileSystem::File(return_inode, "<unix socket>"_sv), O_RDWR | flags));
 	}
 
 	BAN::ErrorOr<void> UnixDomainSocket::connect_impl(const sockaddr* address, socklen_t address_len)
@@ -200,16 +200,24 @@ namespace Kernel
 		if (sockaddr_un.sun_family != AF_UNIX)
 			return BAN::Error::from_errno(EAFNOSUPPORT);
 
-		auto absolute_path = TRY(Process::current().absolute_path_of(sockaddr_un.sun_path));
-		if (auto ret = Process::current().create_file_or_dir(absolute_path, 0755 | S_IFSOCK); ret.is_error())
+		auto bind_path = BAN::StringView(sockaddr_un.sun_path);
+		if (bind_path.empty())
+			return BAN::Error::from_errno(EINVAL);
+
+		// FIXME: This feels sketchy
+		auto parent_file = bind_path.front() == '/'
+			? VirtualFileSystem::get().root_file()
+			: TRY(Process::current().working_directory().clone());
+		if (auto ret = Process::current().create_file_or_dir(parent_file, bind_path, 0755 | S_IFSOCK); ret.is_error())
 		{
 			if (ret.error().get_error_code() == EEXIST)
 				return BAN::Error::from_errno(EADDRINUSE);
 			return ret.release_error();
 		}
-		auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(
+		auto file = TRY(VirtualFileSystem::get().file_from_relative_path(
+			parent_file,
 			Process::current().credentials(),
-			absolute_path,
+			bind_path,
 			O_RDWR
 		));
 

kernel/kernel/OpenFileDescriptorSet.cpp

@@ -38,7 +38,11 @@ namespace Kernel
 
 			auto& open_file = other.m_open_files[fd];
 
-			auto result = BAN::RefPtr<OpenFileDescription>::create(open_file->inode, open_file->path, open_file->offset, open_file->flags);
+			VirtualFileSystem::File temp_file;
+			temp_file.inode = open_file->inode();
+			TRY(temp_file.canonical_path.append(open_file->path()));
+
+			auto result = BAN::RefPtr<OpenFileDescription>::create(BAN::move(temp_file), open_file->offset, open_file->flags);
 
 			if (result.is_error())
 			{
@@ -48,10 +52,10 @@ namespace Kernel
 
 			m_open_files[fd] = result.release_value();
 
-			if (m_open_files[fd]->path == "<pipe wr>"_sv)
+			if (m_open_files[fd]->path() == "<pipe wr>"_sv)
 			{
-				ASSERT(m_open_files[fd]->inode->is_pipe());
-				static_cast<Pipe*>(m_open_files[fd]->inode.ptr())->clone_writing();
+				ASSERT(m_open_files[fd]->inode()->is_pipe());
+				static_cast<Pipe*>(m_open_files[fd]->inode().ptr())->clone_writing();
 			}
 		}
 
@@ -75,7 +79,7 @@ namespace Kernel
 			TRY(file.inode->truncate(0));
 
 		int fd = TRY(get_free_fd());
-		m_open_files[fd] = TRY(BAN::RefPtr<OpenFileDescription>::create(file.inode, BAN::move(file.canonical_path), 0, flags));
+		m_open_files[fd] = TRY(BAN::RefPtr<OpenFileDescription>::create(BAN::move(file), 0, flags));
 
 		return fd;
 	}
@@ -140,7 +144,7 @@ namespace Kernel
 		auto socket = TRY(NetworkManager::get().create_socket(sock_domain, sock_type, 0777, m_credentials.euid(), m_credentials.egid()));
 
 		int fd = TRY(get_free_fd());
-		m_open_files[fd] = TRY(BAN::RefPtr<OpenFileDescription>::create(socket, "<socket>"_sv, 0, O_RDWR | extra_flags));
+		m_open_files[fd] = TRY(BAN::RefPtr<OpenFileDescription>::create(VirtualFileSystem::File(socket, "<socket>"_sv), 0, O_RDWR | extra_flags));
 		return fd;
 	}
 
@@ -149,8 +153,8 @@ namespace Kernel
 		TRY(get_free_fd_pair(fds));
 
 		auto pipe = TRY(Pipe::create(m_credentials));
-		m_open_files[fds[0]] = TRY(BAN::RefPtr<OpenFileDescription>::create(pipe, "<pipe rd>"_sv, 0, O_RDONLY));
-		m_open_files[fds[1]] = TRY(BAN::RefPtr<OpenFileDescription>::create(pipe, "<pipe wr>"_sv, 0, O_WRONLY));
+		m_open_files[fds[0]] = TRY(BAN::RefPtr<OpenFileDescription>::create(VirtualFileSystem::File(pipe, "<pipe rd>"_sv), 0, O_RDONLY));
+		m_open_files[fds[1]] = TRY(BAN::RefPtr<OpenFileDescription>::create(VirtualFileSystem::File(pipe, "<pipe wr>"_sv), 0, O_WRONLY));
 
 		return {};
 	}
@@ -162,10 +166,10 @@ namespace Kernel
 		int result = TRY(get_free_fd());
 		m_open_files[result] = m_open_files[fildes];
 
-		if (m_open_files[result]->path == "<pipe wr>"_sv)
+		if (m_open_files[result]->path() == "<pipe wr>"_sv)
 		{
-			ASSERT(m_open_files[result]->inode->is_pipe());
-			static_cast<Pipe*>(m_open_files[result]->inode.ptr())->clone_writing();
+			ASSERT(m_open_files[result]->inode()->is_pipe());
+			static_cast<Pipe*>(m_open_files[result]->inode().ptr())->clone_writing();
 		}
 
 		return result;
@@ -185,10 +189,10 @@ namespace Kernel
 		m_open_files[fildes2] = m_open_files[fildes];
 		m_open_files[fildes2]->flags &= ~O_CLOEXEC;
 
-		if (m_open_files[fildes2]->path == "<pipe wr>"_sv)
+		if (m_open_files[fildes2]->path() == "<pipe wr>"_sv)
 		{
-			ASSERT(m_open_files[fildes2]->inode->is_pipe());
-			static_cast<Pipe*>(m_open_files[fildes2]->inode.ptr())->clone_writing();
+			ASSERT(m_open_files[fildes2]->inode()->is_pipe());
+			static_cast<Pipe*>(m_open_files[fildes2]->inode().ptr())->clone_writing();
 		}
 
 		return fildes;
@@ -234,7 +238,7 @@ namespace Kernel
 				base_offset = m_open_files[fd]->offset;
 				break;
 			case SEEK_END:
-				base_offset = m_open_files[fd]->inode->size();
+				base_offset = m_open_files[fd]->inode()->size();
 				break;
 			default:
 				return BAN::Error::from_errno(EINVAL);
@@ -258,71 +262,17 @@ namespace Kernel
 	BAN::ErrorOr<void> OpenFileDescriptorSet::truncate(int fd, off_t length)
 	{
 		TRY(validate_fd(fd));
-		return m_open_files[fd]->inode->truncate(length);
-	}
-
-	static void read_stat_from_inode(BAN::RefPtr<Inode> inode, struct stat* out)
-	{
-		out->st_dev		= inode->dev();
-		out->st_ino		= inode->ino();
-		out->st_mode	= inode->mode().mode;
-		out->st_nlink	= inode->nlink();
-		out->st_uid		= inode->uid();
-		out->st_gid		= inode->gid();
-		out->st_rdev	= inode->rdev();
-		out->st_size	= inode->size();
-		out->st_atim	= inode->atime();
-		out->st_mtim	= inode->mtime();
-		out->st_ctim	= inode->ctime();
-		out->st_blksize	= inode->blksize();
-		out->st_blocks	= inode->blocks();
-	}
-
-	BAN::ErrorOr<void> OpenFileDescriptorSet::fstat(int fd, struct stat* out) const
-	{
-		TRY(validate_fd(fd));
-		read_stat_from_inode(m_open_files[fd]->inode, out);
-		return {};
-	}
-
-	BAN::ErrorOr<void> OpenFileDescriptorSet::fstatat(int fd, BAN::StringView path, struct stat* out, int flag)
-	{
-		if (flag & ~AT_SYMLINK_NOFOLLOW)
-			return BAN::Error::from_errno(EINVAL);
-		if (flag == AT_SYMLINK_NOFOLLOW)
-			flag = O_NOFOLLOW;
-
-		BAN::String absolute_path;
-		TRY(absolute_path.append(TRY(path_of(fd))));
-		TRY(absolute_path.push_back('/'));
-		TRY(absolute_path.append(path));
-
-		// FIXME: handle O_SEARCH in fd
-		auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, flag));
-		read_stat_from_inode(file.inode, out);
-
-		return {};
-	}
-
-	BAN::ErrorOr<void> OpenFileDescriptorSet::stat(BAN::StringView absolute_path, struct stat* out, int flag)
-	{
-		if (flag & ~AT_SYMLINK_NOFOLLOW)
-			return BAN::Error::from_errno(EINVAL);
-		if (flag == AT_SYMLINK_NOFOLLOW)
-			flag = O_NOFOLLOW;
-		auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, flag));
-		read_stat_from_inode(file.inode, out);
-		return {};
+		return m_open_files[fd]->inode()->truncate(length);
 	}
 
 	BAN::ErrorOr<void> OpenFileDescriptorSet::close(int fd)
 	{
 		TRY(validate_fd(fd));
 
-		if (m_open_files[fd]->path == "<pipe wr>"_sv)
+		if (m_open_files[fd]->path() == "<pipe wr>"_sv)
 		{
-			ASSERT(m_open_files[fd]->inode->is_pipe());
-			static_cast<Pipe*>(m_open_files[fd]->inode.ptr())->close_writing();
+			ASSERT(m_open_files[fd]->inode()->is_pipe());
+			static_cast<Pipe*>(m_open_files[fd]->inode().ptr())->close_writing();
 		}
 
 		m_open_files[fd].clear();
@@ -351,9 +301,9 @@ namespace Kernel
 	{
 		TRY(validate_fd(fd));
 		auto& open_file = m_open_files[fd];
-		if ((open_file->flags & O_NONBLOCK) && !open_file->inode->can_read())
+		if ((open_file->flags & O_NONBLOCK) && !open_file->inode()->can_read())
 			return 0;
-		size_t nread = TRY(open_file->inode->read(open_file->offset, buffer));
+		size_t nread = TRY(open_file->inode()->read(open_file->offset, buffer));
 		open_file->offset += nread;
 		return nread;
 	}
@@ -362,11 +312,11 @@ namespace Kernel
 	{
 		TRY(validate_fd(fd));
 		auto& open_file = m_open_files[fd];
-		if ((open_file->flags & O_NONBLOCK) && !open_file->inode->can_write())
+		if ((open_file->flags & O_NONBLOCK) && !open_file->inode()->can_write())
 			return 0;
 		if (open_file->flags & O_APPEND)
-			open_file->offset = open_file->inode->size();
-		size_t nwrite = TRY(open_file->inode->write(open_file->offset, buffer));
+			open_file->offset = open_file->inode()->size();
+		size_t nwrite = TRY(open_file->inode()->write(open_file->offset, buffer));
 		open_file->offset += nwrite;
 		return nwrite;
 	}
@@ -377,19 +327,25 @@ namespace Kernel
 		auto& open_file = m_open_files[fd];
 		if (!(open_file->flags & O_RDONLY))
 			return BAN::Error::from_errno(EACCES);
-		return TRY(open_file->inode->list_next_inodes(open_file->offset++, list, list_len));
+		return TRY(open_file->inode()->list_next_inodes(open_file->offset++, list, list_len));
+	}
+
+	BAN::ErrorOr<VirtualFileSystem::File> OpenFileDescriptorSet::file_of(int fd) const
+	{
+		TRY(validate_fd(fd));
+		return TRY(m_open_files[fd]->file.clone());
 	}
 
 	BAN::ErrorOr<BAN::StringView> OpenFileDescriptorSet::path_of(int fd) const
 	{
 		TRY(validate_fd(fd));
-		return m_open_files[fd]->path.sv();
+		return m_open_files[fd]->path();
 	}
 
 	BAN::ErrorOr<BAN::RefPtr<Inode>> OpenFileDescriptorSet::inode_of(int fd)
 	{
 		TRY(validate_fd(fd));
-		return m_open_files[fd]->inode;
+		return m_open_files[fd]->inode();
 	}
 
 	BAN::ErrorOr<int> OpenFileDescriptorSet::flags_of(int fd) const

kernel/kernel/Process.cpp

@@ -96,14 +96,12 @@ namespace Kernel
 	Process* Process::create_kernel()
 	{
 		auto* process = create_process({ 0, 0, 0, 0 }, 0);
-		MUST(process->m_working_directory.push_back('/'));
 		return process;
 	}
 
 	Process* Process::create_kernel(entry_t entry, void* data)
 	{
 		auto* process = create_process({ 0, 0, 0, 0 }, 0);
-		MUST(process->m_working_directory.push_back('/'));
 		auto* thread = MUST(Thread::create_kernel(entry, data, process));
 		process->add_thread(thread);
 		process->register_to_scheduler();
@@ -115,13 +113,15 @@ namespace Kernel
 		auto* process = create_process(credentials, 0);
 		TRY(process->m_credentials.initialize_supplementary_groups());
 
-		MUST(process->m_working_directory.push_back('/'));
+		process->m_working_directory = VirtualFileSystem::get().root_file();
 		process->m_page_table = BAN::UniqPtr<PageTable>::adopt(MUST(PageTable::create_userspace()));
 
 		TRY(process->m_cmdline.push_back({}));
 		TRY(process->m_cmdline.back().append(path));
 
-		process->m_loadable_elf = TRY(load_elf_for_exec(credentials, path, "/"_sv, process->page_table()));
+		auto absolute_path = TRY(process->absolute_path_of(path));
+		auto executable_inode = TRY(VirtualFileSystem::get().file_from_absolute_path(process->m_credentials, absolute_path, O_EXEC)).inode;
+		process->m_loadable_elf = TRY(LibELF::LoadableELF::load_from_inode(process->page_table(), process->m_credentials, executable_inode));
 		if (!process->m_loadable_elf->is_address_space_free())
 		{
 			dprintln("Could not load ELF address space");
@@ -362,7 +362,7 @@ namespace Kernel
 	{
 		LockGuard _(m_process_lock);
 
-		TRY(validate_pointer_access(termios, sizeof(termios), true));
+		TRY(validate_pointer_access(termios, sizeof(struct termios), true));
 
 		auto inode = TRY(m_open_file_descriptors.inode_of(fildes));
 		if (!inode->is_tty())
@@ -381,7 +381,7 @@ namespace Kernel
 
 		LockGuard _(m_process_lock);
 
-		TRY(validate_pointer_access(termios, sizeof(termios), false));
+		TRY(validate_pointer_access(termios, sizeof(struct termios), false));
 
 		auto inode = TRY(m_open_file_descriptors.inode_of(fildes));
 		if (!inode->is_tty())
@@ -394,26 +394,6 @@ namespace Kernel
 		return 0;
 	}
 
-	BAN::ErrorOr<BAN::UniqPtr<LibELF::LoadableELF>> Process::load_elf_for_exec(const Credentials& credentials, BAN::StringView file_path, const BAN::String& cwd, PageTable& page_table)
-	{
-		if (file_path.empty())
-			return BAN::Error::from_errno(ENOENT);
-
-		BAN::String absolute_path;
-
-		if (file_path.front() == '/')
-			TRY(absolute_path.append(file_path));
-		else
-		{
-			TRY(absolute_path.append(cwd));
-			TRY(absolute_path.push_back('/'));
-			TRY(absolute_path.append(file_path));
-		}
-
-		auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(credentials, absolute_path, O_EXEC));
-		return TRY(LibELF::LoadableELF::load_from_inode(page_table, credentials, file.inode));
-	}
-
 	BAN::ErrorOr<long> Process::sys_fork(uintptr_t sp, uintptr_t ip)
 	{
 		auto page_table = BAN::UniqPtr<PageTable>::adopt(TRY(PageTable::create_userspace()));
@@ -434,8 +414,7 @@ namespace Kernel
 			child_exit_status = &m_child_exit_statuses.back();
 		}
 
-		BAN::String working_directory;
-		TRY(working_directory.append(m_working_directory));
+		auto working_directory = TRY(m_working_directory.clone());
 
 		OpenFileDescriptorSet open_file_descriptors(m_credentials);
 		TRY(open_file_descriptors.clone_from(m_open_file_descriptors));
@@ -479,7 +458,10 @@ namespace Kernel
 			LockGuard _(m_process_lock);
 
 			TRY(validate_string_access(path));
-			auto loadable_elf = TRY(load_elf_for_exec(m_credentials, path, m_working_directory, page_table()));
+
+			auto absolute_path = TRY(absolute_path_of(path));
+			auto executable_inode = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, O_EXEC)).inode;
+			auto loadable_elf = TRY(LibELF::LoadableELF::load_from_inode(page_table(), m_credentials, executable_inode));
 
 			BAN::Vector<BAN::String> str_argv;
 			for (int i = 0; argv && argv[i]; i++)
@@ -809,7 +791,7 @@ namespace Kernel
 		}
 	}
 
-	BAN::ErrorOr<void> Process::create_file_or_dir(BAN::StringView path, mode_t mode)
+	BAN::ErrorOr<void> Process::create_file_or_dir(const VirtualFileSystem::File& parent, BAN::StringView path, mode_t mode) const
 	{
 		switch (mode & Inode::Mode::TYPE_MASK)
 		{
@@ -821,22 +803,19 @@ namespace Kernel
 				return BAN::Error::from_errno(ENOTSUP);
 		}
 
-		LockGuard _(m_process_lock);
+		BAN::RefPtr<Inode> parent_inode;
+		BAN::StringView file_name;
 
-		auto absolute_path = TRY(absolute_path_of(path));
-
-		size_t index;
-		for (index = absolute_path.size(); index > 0; index--)
-			if (absolute_path[index - 1] == '/')
-				break;
-
-		auto directory = absolute_path.sv().substring(0, index);
-		auto file_name = absolute_path.sv().substring(index);
-
-		auto parent_inode = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, directory, O_EXEC | O_WRONLY)).inode;
-
-		if (auto ret = parent_inode->find_inode(file_name); !ret.is_error())
-			return BAN::Error::from_errno(EEXIST);
+		if (auto index = path.rfind('/'); index.has_value())
+		{
+			parent_inode = TRY(VirtualFileSystem::get().file_from_relative_path(parent, m_credentials, path.substring(0, index.value()), O_EXEC | O_WRONLY)).inode;
+			file_name = path.substring(index.value() + 1);
+		}
+		else
+		{
+			parent_inode = parent.inode;
+			file_name = path;
+		}
 
 		if (Inode::Mode(mode).ifdir())
 			TRY(parent_inode->create_directory(file_name, mode, m_credentials.euid(), parent_inode->gid()));
@@ -875,23 +854,21 @@ namespace Kernel
 		return false;
 	}
 
-	BAN::ErrorOr<long> Process::open_inode(BAN::RefPtr<Inode> inode, int flags)
+	BAN::ErrorOr<long> Process::open_inode(VirtualFileSystem::File&& file, int flags)
 	{
-		ASSERT(inode);
+		ASSERT(file.inode);
 		LockGuard _(m_process_lock);
-		return TRY(m_open_file_descriptors.open(VirtualFileSystem::File { .inode = inode, .canonical_path = {} }, flags));
+		return TRY(m_open_file_descriptors.open(BAN::move(file), flags));
 	}
 
-	BAN::ErrorOr<long> Process::open_file(BAN::StringView path, int flags, mode_t mode)
+	BAN::ErrorOr<long> Process::open_file_impl(const VirtualFileSystem::File& parent, BAN::StringView path, int flags, mode_t mode)
 	{
 		if ((flags & (O_DIRECTORY | O_CREAT)) == (O_DIRECTORY | O_CREAT))
 			return BAN::Error::from_errno(EINVAL);
 
 		LockGuard _(m_process_lock);
 
-		BAN::String absolute_path = TRY(absolute_path_of(path));
-
-		auto file_or_error = VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, flags | O_NOFOLLOW);
+		auto file_or_error = VirtualFileSystem::get().file_from_relative_path(parent, m_credentials, path, flags | O_NOFOLLOW);
 
 		VirtualFileSystem::File file;
 		if (file_or_error.is_error())
@@ -899,9 +876,9 @@ namespace Kernel
 			if (!(flags & O_CREAT) || file_or_error.error().get_error_code() != ENOENT)
 				return file_or_error.release_error();
 
-			// FIXME: There is a race condition between these lines
-			TRY(create_file_or_dir(absolute_path, (mode & 0777) | Inode::Mode::IFREG));
-			file = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, flags));
+			// FIXME: There is a race condition between next two lines
+			TRY(create_file_or_dir(parent, path, (mode & 0777) | Inode::Mode::IFREG));
+			file = TRY(VirtualFileSystem::get().file_from_relative_path(parent, m_credentials, path, flags));
 		}
 		else
 		{
@@ -914,7 +891,7 @@ namespace Kernel
 			if (!file.inode->mode().ifdir() && (flags & O_DIRECTORY))
 				return BAN::Error::from_errno(ENOTDIR);
 			if (file.inode->mode().iflnk() && !(flags & O_NOFOLLOW))
-				file = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, flags));
+				file = TRY(VirtualFileSystem::get().file_from_relative_path(parent, m_credentials, path, flags));
 		}
 
 		auto inode = file.inode;
@@ -933,7 +910,9 @@ namespace Kernel
 	{
 		LockGuard _(m_process_lock);
 		TRY(validate_string_access(path));
-		return open_file(path, flags, mode);
+		if (path[0] == '/')
+			return open_file_impl(VirtualFileSystem::get().root_file(), path, flags, mode);
+		return open_file_impl(m_working_directory, path, flags, mode);
 	}
 
 	BAN::ErrorOr<long> Process::sys_openat(int fd, const char* path, int flags, mode_t mode)
@@ -942,10 +921,9 @@ namespace Kernel
 
 		TRY(validate_string_access(path));
 
-		BAN::String absolute_path;
-
+		VirtualFileSystem::File parent_file;
 		if (fd == AT_FDCWD)
-			TRY(absolute_path.append(m_working_directory));
+			parent_file = TRY(m_working_directory.clone());
 		else if (path[0] != '/')
 		{
 			int flags = TRY(m_open_file_descriptors.flags_of(fd));
@@ -953,12 +931,10 @@ namespace Kernel
 				return BAN::Error::from_errno(EBADF);
 			if (!TRY(m_open_file_descriptors.inode_of(fd))->mode().ifdir())
 				return BAN::Error::from_errno(ENOTDIR);
-			TRY(absolute_path.append(TRY(m_open_file_descriptors.path_of(fd))));
+			parent_file = TRY(m_open_file_descriptors.file_of(fd));
 		}
-		TRY(absolute_path.push_back('/'));
-		TRY(absolute_path.append(path));
 
-		return open_file(absolute_path, flags, mode);
+		return open_file_impl(parent_file, path, flags, mode);
 	}
 
 	BAN::ErrorOr<long> Process::sys_close(int fd)
@@ -1012,7 +988,7 @@ namespace Kernel
 	{
 		LockGuard _(m_process_lock);
 		TRY(validate_string_access(path));
-		TRY(create_file_or_dir(path, mode));
+		TRY(create_file_or_dir(VirtualFileSystem::get().root_file(), path, mode));
 		return 0;
 	}
 
@@ -1023,7 +999,7 @@ namespace Kernel
 		BAN::StringView path_sv(path);
 		if (!path_sv.empty() && path_sv.back() == '/')
 			path_sv = path_sv.substring(0, path_sv.size() - 1);
-		TRY(create_file_or_dir(path_sv, Inode::Mode::IFDIR | mode));
+		TRY(create_file_or_dir(VirtualFileSystem::get().root_file(), path_sv, Inode::Mode::IFDIR | mode));
 		return 0;
 	}
 
@@ -1047,10 +1023,8 @@ namespace Kernel
 		return 0;
 	}
 
-	BAN::ErrorOr<long> Process::readlink_impl(BAN::StringView absolute_path, char* buffer, size_t bufsize)
+	BAN::ErrorOr<long> Process::readlink_impl(BAN::RefPtr<Inode> inode, char* buffer, size_t bufsize)
 	{
-		auto inode = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, O_NOFOLLOW | O_RDONLY)).inode;
-
 		// FIXME: no allocation needed
 		auto link_target = TRY(inode->link_target());
 
@@ -1067,8 +1041,8 @@ namespace Kernel
 		TRY(validate_pointer_access(buffer, bufsize, true));
 
 		auto absolute_path = TRY(absolute_path_of(path));
-
-		return readlink_impl(absolute_path.sv(), buffer, bufsize);
+		auto file = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, O_NOFOLLOW | O_RDONLY));
+		return readlink_impl(file.inode, buffer, bufsize);
 	}
 
 	BAN::ErrorOr<long> Process::sys_readlinkat(int fd, const char* path, char* buffer, size_t bufsize)
@@ -1077,15 +1051,9 @@ namespace Kernel
 		TRY(validate_string_access(path));
 		TRY(validate_pointer_access(buffer, bufsize, true));
 
-		// FIXME: handle O_SEARCH in fd
-		auto parent_path = TRY(m_open_file_descriptors.path_of(fd));
-
-		BAN::String absolute_path;
-		TRY(absolute_path.append(parent_path));
-		TRY(absolute_path.push_back('/'));
-		TRY(absolute_path.append(path));
-
-		return readlink_impl(absolute_path.sv(), buffer, bufsize);
+		auto parent_file = TRY(m_open_file_descriptors.file_of(fd));
+		auto file = TRY(VirtualFileSystem::get().file_from_relative_path(parent_file, m_credentials, path, O_NOFOLLOW | O_RDONLY));
+		return readlink_impl(file.inode, buffer, bufsize);
 	}
 
 	BAN::ErrorOr<long> Process::sys_pread(int fd, void* buffer, size_t count, off_t offset)
@@ -1461,27 +1429,62 @@ namespace Kernel
 		return {};
 	}
 
+	static void read_stat_from_inode(BAN::RefPtr<Inode> inode, struct stat* out)
+	{
+		out->st_dev		= inode->dev();
+		out->st_ino		= inode->ino();
+		out->st_mode	= inode->mode().mode;
+		out->st_nlink	= inode->nlink();
+		out->st_uid		= inode->uid();
+		out->st_gid		= inode->gid();
+		out->st_rdev	= inode->rdev();
+		out->st_size	= inode->size();
+		out->st_atim	= inode->atime();
+		out->st_mtim	= inode->mtime();
+		out->st_ctim	= inode->ctime();
+		out->st_blksize	= inode->blksize();
+		out->st_blocks	= inode->blocks();
+	}
+
 	BAN::ErrorOr<long> Process::sys_fstat(int fd, struct stat* buf)
 	{
 		LockGuard _(m_process_lock);
 		TRY(validate_pointer_access(buf, sizeof(struct stat), true));
-		TRY(m_open_file_descriptors.fstat(fd, buf));
+
+		auto inode = TRY(m_open_file_descriptors.inode_of(fd));
+		read_stat_from_inode(inode, buf);
 		return 0;
 	}
 
-	BAN::ErrorOr<long> Process::sys_fstatat(int fd, const char* path, struct stat* buf, int flag)
+	BAN::ErrorOr<long> Process::sys_fstatat(int fd, const char* path, struct stat* buf, int flags)
 	{
+		if (flags & ~AT_SYMLINK_NOFOLLOW)
+			return BAN::Error::from_errno(EINVAL);
+		if (flags == AT_SYMLINK_NOFOLLOW)
+			flags = O_NOFOLLOW;
+
 		LockGuard _(m_process_lock);
 		TRY(validate_pointer_access(buf, sizeof(struct stat), true));
-		TRY(m_open_file_descriptors.fstatat(fd, path, buf, flag));
+
+		auto parent_file = TRY(m_open_file_descriptors.file_of(fd));
+		auto inode = TRY(VirtualFileSystem::get().file_from_relative_path(parent_file, m_credentials, path, flags)).inode;
+		read_stat_from_inode(inode, buf);
 		return 0;
 	}
 
-	BAN::ErrorOr<long> Process::sys_stat(const char* path, struct stat* buf, int flag)
+	BAN::ErrorOr<long> Process::sys_stat(const char* path, struct stat* buf, int flags)
 	{
+		if (flags & ~AT_SYMLINK_NOFOLLOW)
+			return BAN::Error::from_errno(EINVAL);
+		if (flags == AT_SYMLINK_NOFOLLOW)
+			flags = O_NOFOLLOW;
+
 		LockGuard _(m_process_lock);
 		TRY(validate_pointer_access(buf, sizeof(struct stat), true));
-		TRY(m_open_file_descriptors.stat(TRY(absolute_path_of(path)), buf, flag));
+
+		auto absolute_path = TRY(absolute_path_of(path));
+		auto inode = TRY(VirtualFileSystem::get().file_from_absolute_path(m_credentials, absolute_path, flags)).inode;
+		read_stat_from_inode(inode, buf);
 		return 0;
 	}
 
@@ -1561,7 +1564,7 @@ namespace Kernel
 			return BAN::Error::from_errno(ENOTDIR);
 
 		LockGuard _(m_process_lock);
-		m_working_directory = BAN::move(file.canonical_path);
+		m_working_directory = BAN::move(file);
 
 		return 0;
 	}
@@ -1572,11 +1575,11 @@ namespace Kernel
 
 		TRY(validate_pointer_access(buffer, size, true));
 
-		if (size < m_working_directory.size() + 1)
+		if (size < m_working_directory.canonical_path.size() + 1)
 			return BAN::Error::from_errno(ERANGE);
 
-		memcpy(buffer, m_working_directory.data(), m_working_directory.size());
-		buffer[m_working_directory.size()] = '\0';
+		memcpy(buffer, m_working_directory.canonical_path.data(), m_working_directory.canonical_path.size());
+		buffer[m_working_directory.canonical_path.size()] = '\0';
 
 		return (long)buffer;
 	}
@@ -2332,11 +2335,11 @@ namespace Kernel
 		LockGuard _(m_process_lock);
 
 		if (path.empty() || path == "."_sv)
-			return m_working_directory;
+			return m_working_directory.canonical_path;
 
 		BAN::String absolute_path;
 		if (path.front() != '/')
-			TRY(absolute_path.append(m_working_directory));
+			TRY(absolute_path.append(m_working_directory.canonical_path));
 
 		if (!absolute_path.empty() && absolute_path.back() != '/')
 			TRY(absolute_path.push_back('/'));

kernel/kernel/Terminal/TTY.cpp

@@ -222,6 +222,9 @@ namespace Kernel
 				case LibInput::Key::Escape:
 					ansi_c_str = "\e";
 					break;
+				case LibInput::Key::Delete:
+					ansi_c_str = "\x7F";
+					break;
 				case LibInput::Key::ArrowUp:
 					ansi_c_str = "\e[A";
 					break;

userspace/programs/Shell/main.cpp

@@ -4,8 +4,6 @@
 #include <BAN/Vector.h>
 
 #include <ctype.h>
-#include <inttypes.h>
-#include <math.h>
 #include <pwd.h>
 #include <stdio.h>
 #include <stdlib.h>
@@ -24,10 +22,10 @@ static int last_return = 0;
 
 static BAN::String hostname;
 
-static void clean_exit()
+static void clean_exit(int exit_code)
 {
 	tcsetattr(0, TCSANOW, &old_termios);
-	exit(0);
+	exit(exit_code);
 }
 
 BAN::Vector<BAN::Vector<BAN::String>> parse_command(BAN::StringView);
@@ -308,7 +306,7 @@ BAN::Optional<int> execute_builtin(BAN::Vector<BAN::String>& args, int fd_in, in
 	}
 	else if (args.front() == "exit"_sv)
 	{
-		clean_exit();
+		clean_exit(0);
 	}
 	else if (args.front() == "export"_sv)
 	{
@@ -353,187 +351,6 @@ BAN::Optional<int> execute_builtin(BAN::Vector<BAN::String>& args, int fd_in, in
 			execl("/bin/Terminal", "Terminal", NULL);
 		waitpid(pid, nullptr, 0);
 	}
-	else if (args.front() == "page-fault-test"_sv)
-	{
-		volatile int* ptr = nullptr;
-		*ptr = 0;
-	}
-	else if (args.front() == "kill-test"_sv)
-	{
-		pid_t pid = fork();
-		if (pid == 0)
-		{
-			fprintf(fout, "child\n");
-			for (;;);
-		}
-		if (pid == -1)
-		{
-			perror("fork");
-			return 1;
-		}
-
-		sleep(1);
-		if (kill(pid, SIGSEGV) == -1)
-		{
-			perror("kill");
-			return 1;
-		}
-	}
-	else if (args.front() == "signal-test"_sv)
-	{
-		pid_t pid = fork();
-		if (pid == 0)
-		{
-			dup2(fileno(fout), STDOUT_FILENO);
-			if (signal(SIGSEGV, [](int) { printf("SIGSEGV\n"); }) == SIG_ERR)
-			{
-				perror("signal");
-				exit(1);
-			}
-			printf("child\n");
-			for (;;);
-		}
-		if (pid == -1)
-		{
-			perror("fork");
-			return 1;
-		}
-
-		sleep(1);
-		if (kill(pid, SIGSEGV) == -1)
-		{
-			perror("kill");
-			return 1;
-		}
-
-		sleep(1);
-		if (kill(pid, SIGTERM) == -1)
-		{
-			perror("kill");
-			return 1;
-		}
-	}
-	else if (args.front() == "printf-test"_sv)
-	{
-		fprintf(fout, " 0.0:   %f\n", 0.0f);
-		fprintf(fout, " 123.0: %f\n", 123.0f);
-		fprintf(fout, " 0.123: %f\n", 0.123f);
-		fprintf(fout, " NAN:   %f\n", NAN);
-		fprintf(fout, "+INF:   %f\n", INFINITY);
-		fprintf(fout, "-INF:   %f\n", -INFINITY);
-	}
-	else if (args.front() == "cd"_sv)
-	{
-		if (args.size() > 2)
-		{
-			fprintf(fout, "cd: too many arguments\n");
-			return 1;
-		}
-
-		BAN::StringView path;
-
-		if (args.size() == 1)
-		{
-			if (const char* path_env = getenv("HOME"))
-				path = path_env;
-			else
-				return 0;
-		}
-		else
-			path = args[1];
-
-		if (chdir(path.data()) == -1)
-			ERROR_RETURN("chdir", 1);
-	}
-	else if (args.front() == "time"_sv)
-	{
-		args.remove(0);
-
-		timespec start, end;
-
-		if (clock_gettime(CLOCK_MONOTONIC, &start) == -1)
-			ERROR_RETURN("clock_gettime", 1);
-
-		int ret = execute_command(args, fd_in, fd_out);
-
-		if (clock_gettime(CLOCK_MONOTONIC, &end) == -1)
-			ERROR_RETURN("clock_gettime", 1);
-
-		uint64_t total_ns = 0;
-		total_ns += (end.tv_sec - start.tv_sec) * 1'000'000'000;
-		total_ns += end.tv_nsec - start.tv_nsec;
-
-		int secs  =  total_ns / 1'000'000'000;
-		int msecs = (total_ns % 1'000'000'000) / 1'000'000;
-
-		fprintf(fout, "took %d.%03d s\n", secs, msecs);
-
-		return ret;
-	}
-	else if (args.front() == "test-strtox")
-	{
-#define TEST(num, base) do { errno = 0; printf("strtol(\"" num "\", nullptr, " #base ") = %ld ", strtol(num, nullptr, base)); puts(errno ? strerrorname_np(errno) : ""); } while (false)
-		TEST("0", 10);
-		TEST("", 10);
-		TEST("+", 10);
-		TEST("123", 10);
-		TEST("-123", 10);
-		TEST("7fffffffffffffff", 10);
-		TEST("7fffffffffffffff", 16);
-		TEST("8000000000000000", 16);
-		TEST("-8000000000000000", 16);
-		TEST("-8000000000000001", 16);
-		TEST("123", 0);
-		TEST("0123", 0);
-		TEST("0x123", 0);
-		TEST("123", 1);
-		TEST("hello", 10);
-		TEST("hello", 36);
-#undef TEST
-#define TEST(num, base) do { errno = 0; printf("strtoul(\"" num "\", nullptr, " #base ") = %lu ", strtoul(num, nullptr, base)); puts(errno ? strerrorname_np(errno) : ""); } while (false)
-		TEST("0", 10);
-		TEST("123", 10);
-		TEST("-123", 10);
-		TEST("-1", 10);
-		TEST("fffffffffffffff", 16);
-		TEST("ffffffffffffffff", 16);
-		TEST("10000000000000000", 16);
-#undef TEST
-#if __enable_sse
-#define TEST(num) do { errno = 0; printf("strtod(\"" num "\", nullptr) = %e ", strtod(num, nullptr)); puts(errno ? strerrorname_np(errno) : ""); } while (false)
-		TEST("0");
-		TEST(".1");
-		TEST("1.");
-		TEST("0x.1");
-		TEST("0x1.");
-		TEST("123");
-		TEST("-123");
-		TEST("0x123");
-		TEST("123.456");
-		TEST("-123.456");
-		TEST("1.2e5");
-		TEST("1.e5");
-		TEST(".2e5");
-		TEST("0x1.2p5");
-		TEST("0x1.p5");
-		TEST("0x.2p5");
-		TEST("1e999");
-		TEST("-1e999");
-		TEST("1e308");
-		TEST("1e-307");
-		TEST("1e309");
-		TEST("1e-308");
-		TEST("0.00000000001e312");
-		TEST("1000000000000e-312");
-		TEST("0e999");
-		TEST("0e-999");
-		TEST("1237754.446f");
-		TEST("inf");
-		TEST("-inf");
-		TEST("nan");
-#undef TEST
-#endif
-	}
 	else
 	{
 		return {};
@@ -916,7 +733,7 @@ int prompt_length()
 void print_prompt()
 {
 	auto prompt = get_prompt();
-	fprintf(stdout, "%.*s", (int)prompt.size(), prompt.data());
+	printf("%.*s", (int)prompt.size(), prompt.data());
 	fflush(stdout);
 }
 
@@ -978,13 +795,19 @@ int main(int argc, char** argv)
 		int chi = getchar();
 		if (chi == EOF)
 		{
-			if (errno == EINTR)
+			if (errno != EINTR)
 			{
-				clearerr(stdin);
-				continue;
-			}
 				perror("getchar");
-			return 1;
+				clean_exit(1);
+			}
+
+			clearerr(stdin);
+			buffers = history;
+			MUST(buffers.emplace_back(""_sv));
+			col = 0;
+			putchar('\n');
+			print_prompt();
+			continue;
 		}
 
 		uint8_t ch = chi;
@@ -995,11 +818,11 @@ int main(int argc, char** argv)
 
 			ASSERT((ch & 0xC0) == 0x80);
 
-			fputc(ch, stdout);
+			putchar(ch);
 			MUST(buffers[index].insert(ch, col++));
 			if (waiting_utf8 == 0)
 			{
-				fprintf(stdout, "\e[s%s\e[u", buffers[index].data() + col);
+				printf("\e[s%s\e[u", buffers[index].data() + col);
 				fflush(stdout);
 			}
 			continue;
@@ -1015,7 +838,7 @@ int main(int argc, char** argv)
 			else
 				ASSERT_NOT_REACHED();
 
-			fputc(ch, stdout);
+			putchar(ch);
 			MUST(buffers[index].insert(ch, col++));
 			continue;
 		}
@@ -1029,18 +852,18 @@ int main(int argc, char** argv)
 			ch = getchar();
 			switch (ch)
 			{
-				case 'A': if (index > 0)					{ index--; col = buffers[index].size(); fprintf(stdout, "\e[%dG%s\e[K", prompt_length() + 1, buffers[index].data()); fflush(stdout); } break;
-				case 'B': if (index < buffers.size() - 1)	{ index++; col = buffers[index].size(); fprintf(stdout, "\e[%dG%s\e[K", prompt_length() + 1, buffers[index].data()); fflush(stdout); } break;
-				case 'C': if (col < buffers[index].size())	{ col++; while ((buffers[index][col - 1] & 0xC0) == 0x80) col++; fprintf(stdout, "\e[C"); fflush(stdout); } break;
-				case 'D': if (col > 0)						{ while ((buffers[index][col - 1] & 0xC0) == 0x80) col--; col--; fprintf(stdout, "\e[D"); fflush(stdout); } break;
+				case 'A': if (index > 0)					{ index--; col = buffers[index].size(); printf("\e[%dG%s\e[K", prompt_length() + 1, buffers[index].data()); fflush(stdout); } break;
+				case 'B': if (index < buffers.size() - 1)	{ index++; col = buffers[index].size(); printf("\e[%dG%s\e[K", prompt_length() + 1, buffers[index].data()); fflush(stdout); } break;
+				case 'C': if (col < buffers[index].size())	{ col++; while ((buffers[index][col - 1] & 0xC0) == 0x80) col++; printf("\e[C"); fflush(stdout); } break;
+				case 'D': if (col > 0)						{ while ((buffers[index][col - 1] & 0xC0) == 0x80) col--; col--; printf("\e[D"); fflush(stdout); } break;
 			}
 			break;
 		case '\x0C': // ^L
 		{
 			int x = prompt_length() + character_length(buffers[index].sv().substring(col)) + 1;
-			fprintf(stdout, "\e[H\e[J");
+			printf("\e[H\e[J");
 			print_prompt();
-			fprintf(stdout, "%s\e[u\e[1;%dH", buffers[index].data(), x);
+			printf("%s\e[u\e[1;%dH", buffers[index].data(), x);
 			fflush(stdout);
 			break;
 		}
@@ -1050,27 +873,37 @@ int main(int argc, char** argv)
 				while ((buffers[index][col - 1] & 0xC0) == 0x80)
 					buffers[index].remove(--col);
 				buffers[index].remove(--col);
-				fprintf(stdout, "\b\e[s%s \e[u", buffers[index].data() + col);
+				printf("\b\e[s%s \e[u", buffers[index].data() + col);
 				fflush(stdout);
 			}
 			break;
 		case '\x01': // ^A
 			col = 0;
-			fprintf(stdout, "\e[%dG", prompt_length() + 1);
+			printf("\e[%dG", prompt_length() + 1);
 			fflush(stdout);
 			break;
 		case '\x03': // ^C
-			fputc('\n', stdout);
+			putchar('\n');
 			print_prompt();
 			buffers[index].clear();
 			col = 0;
 			break;
 		case '\x04': // ^D
-			fprintf(stdout, "\n");
-			clean_exit();
+			putchar('\n');
+			clean_exit(0);
+			break;
+		case '\x7F': // delete
+			if (col < buffers[index].size())
+			{
+				buffers[index].remove(col);
+				while (col < buffers[index].size() && (buffers[index][col] & 0xC0) == 0x80)
+					buffers[index].remove(col);
+				printf("\e[s%s \e[u", buffers[index].data() + col);
+				fflush(stdout);
+			}
 			break;
 		case '\n':
-			fputc('\n', stdout);
+			putchar('\n');
 			if (!buffers[index].empty())
 			{
 				last_return = parse_and_execute_command(buffers[index]);
@@ -1088,13 +921,13 @@ int main(int argc, char** argv)
 		default:
 			MUST(buffers[index].insert(ch, col++));
 			if (col == buffers[index].size())
-				fputc(ch, stdout);
+				putchar(ch);
 			else
-				fprintf(stdout, "%c\e[s%s\e[u", ch, buffers[index].data() + col);
+				printf("%c\e[s%s\e[u", ch, buffers[index].data() + col);
 			fflush(stdout);
 			break;
 		}
 	}
 
-	clean_exit();
+	clean_exit(0);
 }