init commit

editor.cpp

@@ -0,0 +1,92 @@
+/* editor.cpp — GNU readline line editor, history and term helpers
+ * (is_terminal, term_width). The interactive prompt is handled by
+ * libreadline instead of a hand-rolled raw-mode terminal editor. */
+#include "bantam.hpp"
+#include <cstdio>
+#include <cstdlib>
+#include <cstring>
+#include <readline/readline.h>
+#include <readline/history.h>
+#include <sys/ioctl.h>
+#include <unistd.h>
+
+/* ----------------------------- globals ------------------------------- */
+static std::string g_hist_file;
+
+static std::string home_dir() {
+  const char *h = std::getenv("HOME");
+  if (h && *h) return h;
+  return ".";
+}
+
+/* ----------------------------- history -------------------------------- */
+void load_history() {
+  g_hist_file = home_dir() + "/.bantam_history";
+  using_history();
+  /* A missing history file is not an error. */
+  read_history(g_hist_file.c_str());
+}
+void add_history(std::string_view s) {
+  if (s.empty()) return;
+  std::string line(s);
+  /* Skip an entry identical to the immediately preceding one. */
+  if (history_length > 0) {
+    HIST_ENTRY *last = history_get(history_base + history_length - 1);
+    if (last && last->line && line == last->line) return;
+  }
+  ::add_history(line.c_str());
+}
+void save_history() {
+  if (g_hist_file.empty()) return;
+  write_history(g_hist_file.c_str());
+}
+
+/* ----------------------------- read helpers --------------------------- */
+std::string read_plain(std::string_view prompt, bool &ok) {
+  if (!prompt.empty()) fputs(std::string(prompt).c_str(), stdout);
+  fflush(stdout);
+  char *line = nullptr; size_t cap = 0; ssize_t n = getline(&line, &cap, stdin);
+  if (n < 0) { free(line); clearerr(stdin); ok = false; return ""; }
+  while (n > 0 && (line[n - 1] == '\n' || line[n - 1] == '\r')) line[--n] = '\0';
+  std::string r(line, (size_t)n);
+  free(line);
+  ok = true;
+  return r;
+}
+
+/* ----------------------------- readline editor ------------------------ */
+std::string read_line(std::string_view prompt, bool &ok) {
+  if (!is_terminal(STDIN_FILENO)) return read_plain(prompt, ok);
+  /* Enter (\r) submits the line; Ctrl+J inserts a literal newline so a
+   * multi-line prompt can be composed before submitting. */
+  rl_bind_key('\n', rl_insert);
+  char *line = readline(prompt.empty() ? "" : std::string(prompt).c_str());
+  if (!line) { ok = false; return ""; }
+  std::string r(line);
+  free(line);
+  ok = true;
+  return r;
+}
+
+/* ----------------------------- term helpers --------------------------- */
+int is_terminal(int fd) { return isatty(fd) != 0; }
+
+int term_width() {
+#ifdef TIOCGWINSZ
+  struct winsize ws{};
+  if (ioctl(STDIN_FILENO, TIOCGWINSZ, &ws) == 0 && ws.ws_col > 0) return (int)ws.ws_col;
+  if (ioctl(STDOUT_FILENO, TIOCGWINSZ, &ws) == 0 && ws.ws_col > 0) return (int)ws.ws_col;
+#endif
+  const char *c = std::getenv("COLUMNS");
+  if (c && *c) { int n = std::atoi(c); if (n > 0) return n; }
+  FILE *p = popen("tput cols 2>/dev/null", "r");
+  if (p) {
+    char buf[32];
+    if (fgets(buf, sizeof buf, p)) {
+      int n = std::atoi(buf);
+      pclose(p);
+      if (n > 0) return n;
+    } else pclose(p);
+  }
+  return 80;
+}