#include #include #include #include #include #include #include #include #include #include #include #include #include #include #define ERROR_RETURN(__msg, __ret) do { perror(__msg); return __ret; } while (false) extern char** environ; static struct termios old_termios, new_termios; static char s_shell_path[PATH_MAX]; static int last_return = 0; static BAN::String hostname; static BAN::Vector> parse_command(BAN::StringView); static BAN::Optional parse_dollar(BAN::StringView command, size_t& i) { ASSERT(command[i] == '$'); if (++i >= command.size()) return BAN::String("$"_sv); if (command[i] == '?') { i++; return MUST(BAN::String::formatted("{}", last_return)); } if (isalnum(command[i])) { size_t len = 1; for (; i + len < command.size(); len++) if (!isalnum(command[i + len])) break; BAN::String name = command.substring(i, len); i += len - 1; if (const char* value = getenv(name.data())) return BAN::String(value); return BAN::String(); } else if (command[i] == '{') { size_t len = 1; for (; i + len < command.size(); len++) { if (command[i + len] == '}') break; if (!isalnum(command[i + len])) return {}; } if (i + len >= command.size()) return {}; BAN::String name = command.substring(i + 1, len - 1); i += len; if (const char* value = getenv(name.data())) return BAN::String(value); return BAN::String(); } else if (command[i] == '[') { return {}; } else if (command[i] == '(') { size_t len = 1; int count = 1; for (; i + len < command.size(); len++) { if (command[i + len] == '(') count++; if (command[i + len] == ')') count--; if (count == 0) break; } if (count != 0) return {}; BAN::String subcommand = command.substring(i + 1, len - 1); char temp[3] { '-', 'c', '\0' }; BAN::Vector argv; MUST(argv.push_back(s_shell_path)); MUST(argv.push_back(temp)); MUST(argv.push_back((char*)subcommand.data())); MUST(argv.push_back(nullptr)); int fds[2]; if (pipe(fds) == -1) ERROR_RETURN("pipe", {}); pid_t pid = fork(); if (pid == 0) { if (dup2(fds[1], STDOUT_FILENO) == -1) { perror("dup2"); exit(1); } close(fds[0]); close(fds[1]); execv(argv.front(), argv.data()); perror("execv"); exit(1); } if (pid == -1) ERROR_RETURN("fork", {}); close(fds[1]); char buffer[100]; BAN::String output; while (ssize_t ret = read(fds[0], buffer, sizeof(buffer))) { if (ret == -1) { perror("read"); break; } MUST(output.append(BAN::StringView(buffer, ret))); } close(fds[0]); int status; if (waitpid(pid, &status, 0) == -1) ERROR_RETURN("waitpid", {}); while (!output.empty() && output.back() == '\n') output.pop_back(); i += len; return output; } BAN::String temp = "$"_sv; MUST(temp.push_back(command[i])); return temp; } static BAN::StringView strip_whitespace(BAN::StringView sv) { size_t leading = 0; while (leading < sv.size() && isspace(sv[leading])) leading++; sv = sv.substring(leading); size_t trailing = 0; while (trailing < sv.size() && isspace(sv[sv.size() - trailing - 1])) trailing++; sv = sv.substring(0, sv.size() - trailing); return sv; } static BAN::Vector> parse_command(BAN::StringView command_view) { enum class State { Normal, SingleQuote, DoubleQuote, }; command_view = strip_whitespace(command_view); BAN::Vector> result; BAN::Vector command_args; State state = State::Normal; BAN::String current_arg; for (size_t i = 0; i < command_view.size(); i++) { char c = command_view[i]; if (i + 1 < command_view.size() && c == '\\') { char next = command_view[i + 1]; if (next == '\'' || next == '"') { if (i + 1 < command_view.size()) MUST(current_arg.push_back(next)); i++; continue; } } switch (state) { case State::Normal: if (c == '\'') state = State::SingleQuote; else if (c == '"') state = State::DoubleQuote; else if (c == '$') { auto expansion = parse_dollar(command_view, i); if (!expansion.has_value()) { fprintf(stderr, "bad substitution\n"); return {}; } MUST(current_arg.append(expansion.value())); } else if (c == '|') { if (!current_arg.empty()) MUST(command_args.push_back(current_arg)); current_arg.clear(); MUST(result.push_back(command_args)); command_args.clear(); } else if (!isspace(c)) MUST(current_arg.push_back(c)); else { if (!current_arg.empty()) { MUST(command_args.push_back(current_arg)); current_arg.clear(); } } break; case State::SingleQuote: if (c == '\'') state = State::Normal; else MUST(current_arg.push_back(c)); break; case State::DoubleQuote: if (c == '"') state = State::Normal; else if (c != '$') MUST(current_arg.push_back(c)); else { auto expansion = parse_dollar(command_view, i); if (!expansion.has_value()) { fprintf(stderr, "bad substitution\n"); return {}; } MUST(current_arg.append(expansion.value())); } break; } } // FIXME: handle state != State::Normal MUST(command_args.push_back(BAN::move(current_arg))); MUST(result.push_back(BAN::move(command_args))); return result; } static int execute_command(BAN::Vector& args, int fd_in, int fd_out); static int source_script(const BAN::String& path); static BAN::Optional execute_builtin(BAN::Vector& args, int fd_in, int fd_out) { if (args.empty()) return 0; FILE* fout = stdout; bool should_close = false; if (fd_out != STDOUT_FILENO) { int fd_dup = dup(fd_out); if (fd_dup == -1) ERROR_RETURN("dup", 1); fout = fdopen(fd_dup, "w"); if (fout == nullptr) ERROR_RETURN("fdopen", 1); should_close = true; } BAN::ScopeGuard _([fout, should_close] { if (should_close) fclose(fout); }); if (args.front() == "clear"_sv) { fprintf(fout, "\e[H\e[2J"); fflush(fout); } else if (args.front() == "exit"_sv) { exit(0); } else if (args.front() == "export"_sv) { bool first = false; for (const auto& arg : args) { if (first) { first = false; continue; } auto split = MUST(arg.sv().split('=', true)); if (split.size() != 2) continue; if (setenv(BAN::String(split[0]).data(), BAN::String(split[1]).data(), true) == -1) ERROR_RETURN("setenv", 1); } } else if (args.front() == "source"_sv) { if (args.size() != 2) { fprintf(fout, "usage: source FILE\n"); return 1; } return source_script(args[1]); } else if (args.front() == "env"_sv) { char** current = environ; while (*current) fprintf(fout, "%s\n", *current++); } 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() == "start-gui"_sv) { pid_t pid = fork(); if (pid == 0) execl("/bin/WindowServer", "WindowServer", NULL); if (fork() == 0) execl("/bin/Terminal", "Terminal", NULL); waitpid(pid, nullptr, 0); } else { return {}; } return 0; } static pid_t execute_command_no_wait(BAN::Vector& args, int fd_in, int fd_out, pid_t pgrp) { if (args.empty()) return 0; BAN::Vector cmd_args; MUST(cmd_args.reserve(args.size() + 1)); for (const auto& arg : args) MUST(cmd_args.push_back((char*)arg.data())); MUST(cmd_args.push_back(nullptr)); // do PATH resolution BAN::String executable_file; if (!args.front().sv().contains('/')) { const char* path_env_cstr = getenv("PATH"); if (path_env_cstr == nullptr) path_env_cstr = ""; auto path_env_list = MUST(BAN::StringView(path_env_cstr).split(':')); for (auto path_env : path_env_list) { BAN::String test_file = path_env; MUST(test_file.push_back('/')); MUST(test_file.append(args.front())); struct stat st; if (stat(test_file.data(), &st) == 0) { executable_file = BAN::move(test_file); break; } } } else { executable_file = args.front(); } // Verify that the file exists is executable { struct stat st; if (executable_file.empty() || stat(executable_file.data(), &st) == -1) { fprintf(stderr, "command not found: %s\n", args.front().data()); return -1; } if ((st.st_mode & 0111) == 0) { fprintf(stderr, "permission denied: %s\n", executable_file.data()); return -1; } } pid_t pid = fork(); if (pid == 0) { if (fd_in != STDIN_FILENO) { if (dup2(fd_in, STDIN_FILENO) == -1) { perror("dup2"); exit(1); } close(fd_in); } if (fd_out != STDOUT_FILENO) { if (dup2(fd_out, STDOUT_FILENO) == -1) { perror("dup2"); exit(1); } close(fd_out); } execv(executable_file.data(), cmd_args.data()); perror("execv"); exit(1); } if (pid == -1) ERROR_RETURN("fork", -1); if (pgrp == 0 && isatty(0)) { if(setpgid(pid, pid) == -1) perror("setpgid"); if (tcsetpgrp(0, pid) == -1) perror("tcsetpgrp"); } else { setpgid(pid, pgrp); } return pid; } static int execute_command(BAN::Vector& args, int fd_in, int fd_out) { pid_t pid = execute_command_no_wait(args, fd_in, fd_out, 0); if (pid == -1) return 1; int status; if (waitpid(pid, &status, 0) == -1) ERROR_RETURN("waitpid", 1); if (isatty(0) && tcsetpgrp(0, getpgrp()) == -1) ERROR_RETURN("tcsetpgrp", 1); if (WIFSIGNALED(status)) fprintf(stderr, "Terminated by signal %d\n", WTERMSIG(status)); return WEXITSTATUS(status); } static int execute_piped_commands(BAN::Vector>& commands) { if (commands.empty()) return 0; if (commands.size() == 1) { auto& command = commands.front(); if (auto ret = execute_builtin(command, STDIN_FILENO, STDOUT_FILENO); ret.has_value()) return ret.value(); return execute_command(command, STDIN_FILENO, STDOUT_FILENO); } BAN::Vector exit_codes(commands.size(), 0); BAN::Vector processes(commands.size(), -1); pid_t pgrp = 0; int next_stdin = STDIN_FILENO; for (size_t i = 0; i < commands.size(); i++) { bool last = (i == commands.size() - 1); int pipefd[2] { -1, STDOUT_FILENO }; if (!last && pipe(pipefd) == -1) { if (i > 0) close(next_stdin); perror("pipe"); break; } auto builtin_ret = execute_builtin(commands[i], next_stdin, pipefd[1]); if (builtin_ret.has_value()) exit_codes[i] = builtin_ret.value(); else { pid_t pid = execute_command_no_wait(commands[i], next_stdin, pipefd[1], pgrp); processes[i] = pid; if (pgrp == 0) pgrp = pid; } if (next_stdin != STDIN_FILENO) close(next_stdin); if (pipefd[1] != STDOUT_FILENO) close(pipefd[1]); next_stdin = pipefd[0]; } for (size_t i = 0; i < commands.size(); i++) { if (processes[i] == -1) continue; int status; if (waitpid(processes[i], &status, 0) == -1) { perror("waitpid"); exit_codes[i] = 69420; continue; } if (WIFSIGNALED(status)) fprintf(stderr, "Terminated by signal %d\n", WTERMSIG(status)); if (WEXITSTATUS(status)) exit_codes[i] = WEXITSTATUS(status); } if (isatty(0) && tcsetpgrp(0, getpgrp()) == -1) ERROR_RETURN("tcsetpgrp", 1); return exit_codes.back(); } static int parse_and_execute_command(BAN::StringView command) { if (command.empty()) return 0; auto parsed_commands = parse_command(command); if (parsed_commands.empty()) return 0; tcsetattr(0, TCSANOW, &old_termios); int ret = execute_piped_commands(parsed_commands); tcsetattr(0, TCSANOW, &new_termios); return ret; } static int source_script(const BAN::String& path) { FILE* fp = fopen(path.data(), "r"); if (fp == nullptr) ERROR_RETURN("fopen", 1); int ret = 0; BAN::String command; char temp_buffer[128]; while (fgets(temp_buffer, sizeof(temp_buffer), fp)) { MUST(command.append(temp_buffer)); if (command.back() != '\n') continue; command.pop_back(); if (!command.empty()) if (int temp = parse_and_execute_command(command)) ret = temp; command.clear(); } if (!command.empty()) if (int temp = parse_and_execute_command(command)) ret = temp; fclose(fp); return ret; } static bool exists(const BAN::String& path) { struct stat st; return stat(path.data(), &st) == 0; } static int source_shellrc() { if (char* home = getenv("HOME")) { BAN::String path(home); MUST(path.append("/.shellrc"_sv)); if (exists(path)) return source_script(path); } return 0; } static int character_length(BAN::StringView prompt) { int length { 0 }; bool in_escape { false }; for (char c : prompt) { if (in_escape) { if (isalpha(c)) in_escape = false; } else { if (c == '\e') in_escape = true; else if (((uint8_t)c & 0xC0) != 0x80) length++; } } return length; } static BAN::String get_prompt() { const char* raw_prompt = getenv("PS1"); if (raw_prompt == nullptr) return "$ "_sv; BAN::String prompt; for (int i = 0; raw_prompt[i]; i++) { char ch = raw_prompt[i]; if (ch == '\\') { switch (raw_prompt[++i]) { case 'e': MUST(prompt.push_back('\e')); break; case 'n': MUST(prompt.push_back('\n')); break; case '\\': MUST(prompt.push_back('\\')); break; case '~': { char buffer[256]; if (getcwd(buffer, sizeof(buffer)) == nullptr) strcpy(buffer, strerrorname_np(errno)); const char* home = getenv("HOME"); size_t home_len = home ? strlen(home) : 0; if (home && strncmp(buffer, home, home_len) == 0) { MUST(prompt.push_back('~')); MUST(prompt.append(buffer + home_len)); } else { MUST(prompt.append(buffer)); } break; } case 'u': { static char* username = nullptr; if (username == nullptr) { auto* passwd = getpwuid(geteuid()); if (passwd == nullptr) break; username = new char[strlen(passwd->pw_name) + 1]; strcpy(username, passwd->pw_name); endpwent(); } MUST(prompt.append(username)); break; } case 'h': { MUST(prompt.append(hostname)); break; } case '\0': MUST(prompt.push_back('\\')); break; default: MUST(prompt.push_back('\\')); MUST(prompt.push_back(*raw_prompt)); break; } } else { MUST(prompt.push_back(ch)); } } return prompt; } static int prompt_length() { return character_length(get_prompt()); } static void print_prompt() { auto prompt = get_prompt(); printf("%.*s", (int)prompt.size(), prompt.data()); fflush(stdout); } int main(int argc, char** argv) { realpath(argv[0], s_shell_path); struct sigaction sa; sa.sa_flags = 0; sa.sa_handler = [](int) {}; sigaction(SIGINT, &sa, nullptr); sa.sa_handler = SIG_IGN; sigaction(SIGTTOU, &sa, nullptr); tcgetattr(0, &old_termios); char hostname_buffer[HOST_NAME_MAX]; if (gethostname(hostname_buffer, sizeof(hostname_buffer)) == 0) { MUST(hostname.append(hostname_buffer)); } new_termios = old_termios; new_termios.c_lflag &= ~(ECHO | ICANON); tcsetattr(0, TCSANOW, &new_termios); atexit([]() { tcsetattr(0, TCSANOW, &old_termios); }); for (int i = 1; i < argc; i++) { if (argv[i][0] != '-') return source_script(BAN::String(argv[i])); if (strcmp(argv[i], "-c") == 0) { if (i + 1 >= argc) { printf("-c requires an argument\n"); return 1; } auto commands = parse_command(BAN::String(argv[i + 1])); return execute_piped_commands(commands); } else if (strcmp(argv[i], "-v") == 0 || strcmp(argv[i], "--version") == 0) { printf("banan-sh 1.0\n"); return 0; } else if (strcmp(argv[i], "-h") == 0 || strcmp(argv[i], "--help") == 0) { printf("usage: %s [options...]\n", argv[0]); printf(" -c run following argument as an argument\n"); printf(" -v, --version print version information and exit\n"); printf(" -h, --help print this message and exit\n"); return 0; } else { printf("unknown argument '%s'\n", argv[i]); return 1; } } source_shellrc(); BAN::Vector buffers, history; MUST(buffers.emplace_back(""_sv)); size_t index = 0; size_t col = 0; int waiting_utf8 = 0; print_prompt(); while (true) { int chi = getchar(); if (chi == EOF) { if (errno != EINTR) { perror("getchar"); return 1; } clearerr(stdin); buffers = history; MUST(buffers.emplace_back(""_sv)); col = 0; putchar('\n'); print_prompt(); continue; } uint8_t ch = chi; if (waiting_utf8 > 0) { waiting_utf8--; ASSERT((ch & 0xC0) == 0x80); putchar(ch); MUST(buffers[index].insert(ch, col++)); if (waiting_utf8 == 0) { printf("\e[s%s\e[u", buffers[index].data() + col); fflush(stdout); } continue; } else if (ch & 0x80) { if ((ch & 0xE0) == 0xC0) waiting_utf8 = 1; else if ((ch & 0xF0) == 0xE0) waiting_utf8 = 2; else if ((ch & 0xF8) == 0xF0) waiting_utf8 = 3; else ASSERT_NOT_REACHED(); putchar(ch); MUST(buffers[index].insert(ch, col++)); continue; } switch (ch) { case '\e': { ch = getchar(); if (ch != '[') break; ch = getchar(); int value = 0; while (isdigit(ch)) { value = (value * 10) + (ch - '0'); ch = getchar(); } switch (ch) { 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; case '~': switch (value) { case 3: // delete if (col >= buffers[index].size()) break; 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; } } break; } case '\x0C': // ^L { int x = prompt_length() + character_length(buffers[index].sv().substring(col)) + 1; printf("\e[H\e[J"); print_prompt(); printf("%s\e[u\e[1;%dH", buffers[index].data(), x); fflush(stdout); break; } case '\b': if (col <= 0) break; while ((buffers[index][col - 1] & 0xC0) == 0x80) col--; col--; printf("\e[D"); fflush(stdout); break; case '\x01': // ^A col = 0; printf("\e[%dG", prompt_length() + 1); fflush(stdout); break; case '\x03': // ^C putchar('\n'); print_prompt(); buffers[index].clear(); col = 0; break; case '\x04': // ^D putchar('\n'); return 0; case '\x7F': // backspace if (col <= 0) break; while ((buffers[index][col - 1] & 0xC0) == 0x80) buffers[index].remove(--col); buffers[index].remove(--col); printf("\b\e[s%s \e[u", buffers[index].data() + col); fflush(stdout); break; case '\n': putchar('\n'); if (!buffers[index].empty()) { last_return = parse_and_execute_command(buffers[index]); MUST(history.push_back(buffers[index])); buffers = history; MUST(buffers.emplace_back(""_sv)); } print_prompt(); index = buffers.size() - 1; col = 0; break; case '\t': // FIXME: Implement tab completion or something break; default: MUST(buffers[index].insert(ch, col++)); if (col == buffers[index].size()) putchar(ch); else printf("%c\e[s%s\e[u", ch, buffers[index].data() + col); fflush(stdout); break; } } }