113 lines
3.7 KiB
C++
113 lines
3.7 KiB
C++
/* editor.cpp — GNU readline line editor, history and term helpers
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* (is_terminal, term_width). The interactive prompt is handled by
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* libreadline instead of a hand-rolled raw-mode terminal editor. */
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#include "bantam.hpp"
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#include <cstdio>
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#include <cstdlib>
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#include <cstring>
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#include <readline/readline.h>
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#include <readline/history.h>
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#include <sys/ioctl.h>
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#include <unistd.h>
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/* ----------------------------- globals ------------------------------- */
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static std::string g_hist_file;
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static std::string home_dir() {
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const char *h = std::getenv("HOME");
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if (h && *h) return h;
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return ".";
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}
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/* ----------------------------- history -------------------------------- */
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void load_history() {
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g_hist_file = home_dir() + "/.bantam_history";
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using_history();
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/* A missing history file is not an error. */
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read_history(g_hist_file.c_str());
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}
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void add_history(std::string_view s) {
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if (s.empty()) return;
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std::string line(s);
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/* Skip an entry identical to the immediately preceding one. */
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if (history_length > 0) {
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HIST_ENTRY *last = history_get(history_base + history_length - 1);
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if (last && last->line && line == last->line) return;
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}
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::add_history(line.c_str());
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}
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void save_history() {
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if (g_hist_file.empty()) return;
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write_history(g_hist_file.c_str());
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}
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/* ----------------------------- read helpers --------------------------- */
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std::string read_plain(std::string_view prompt, bool &ok) {
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if (!prompt.empty()) fputs(std::string(prompt).c_str(), stdout);
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fflush(stdout);
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char *line = nullptr; size_t cap = 0; ssize_t n = getline(&line, &cap, stdin);
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if (n < 0) { free(line); clearerr(stdin); ok = false; return ""; }
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while (n > 0 && (line[n - 1] == '\n' || line[n - 1] == '\r')) line[--n] = '\0';
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std::string r(line, (size_t)n);
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free(line);
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ok = true;
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return r;
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}
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/* ----------------------------- readline editor ------------------------ */
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static void ensure_readline_init() {
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static bool initialized = false;
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if (initialized) return;
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initialized = true;
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rl_initialize();
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#if !defined(__APPLE__) && defined(RL_READLINE_VERSION) && (RL_READLINE_VERSION >= 0x0500)
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/* On GNU Readline (Linux, FreeBSD), terminal raw mode clears ICRNL so
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* Enter sends '\r' (rl_newline = submit) while Ctrl+J sends '\n'
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* (rl_insert = literal newline). On macOS / BSD libedit (EditLine),
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* ICRNL remains enabled in termios (translating Enter '\r' into '\n') and
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* '\n' is the sole accept-line key (ed-newline), so rebinding '\n' to
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* rl_insert prevents submitting any prompt. */
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if (!rl_library_version || std::strncmp(rl_library_version, "EditLine", 8) != 0) {
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rl_bind_key('\n', rl_insert);
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rl_bind_key('\r', rl_newline);
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}
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#endif
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}
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std::string read_line(std::string_view prompt, bool &ok) {
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if (!is_terminal(STDIN_FILENO)) return read_plain(prompt, ok);
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ensure_readline_init();
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char *line = readline(prompt.empty() ? "" : std::string(prompt).c_str());
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setup_signal_handler();
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if (!line) {
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if (g_interrupted) {
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g_interrupted = 0;
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std::fputc('\n', stdout);
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std::fflush(stdout);
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ok = true;
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return "";
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}
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ok = false;
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return "";
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}
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std::string r(line);
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free(line);
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ok = true;
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return r;
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}
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/* ----------------------------- term helpers --------------------------- */
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int is_terminal(int fd) { return isatty(fd) != 0; }
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int term_width() {
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#ifdef TIOCGWINSZ
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struct winsize ws{};
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if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == 0 && ws.ws_col > 0) return (int)ws.ws_col;
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if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) == 0 && ws.ws_col > 0) return (int)ws.ws_col;
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if (ioctl(STDERR_FILENO, TIOCGWINSZ, &ws) == 0 && ws.ws_col > 0) return (int)ws.ws_col;
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#endif
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const char *c = std::getenv("COLUMNS");
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if (c && *c) { int n = std::atoi(c); if (n > 0) return n; }
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return 80;
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}
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