taicpp: port shell, sandbox, pty, glow, markdown, diff and speech helpers from tai.py

Differentially verified against tai.py (4890 cases incl. real pty runs).

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

taicpp/src/shell/shellio.cpp

@@ -0,0 +1,73 @@
+#include "shellio.h"
+#include "ansi.h"
+#include "utf8.h"
+#include <cstdio>
+#include <fcntl.h>
+#include <iostream>
+#include <termios.h>
+#include <unistd.h>
+namespace detz::shell {
+namespace {
+// getpass.getpass(prompt): prompt on the tty, no echo, newline after
+std::optional<std::string> GetPass(const std::string& prompt) {
+  int fd = ::open("/dev/tty", O_RDWR | O_NOCTTY);
+  bool own = fd >= 0;
+  if (fd < 0) fd = 0;
+  struct termios old, quiet;
+  bool changed = false;
+  if (::tcgetattr(fd, &old) == 0) {
+    quiet = old;
+    quiet.c_lflag &= ~(tcflag_t)ECHO;
+    changed = ::tcsetattr(fd, TCSAFLUSH, &quiet) == 0;
+  }
+  int out = own ? fd : 2;
+  (void)!::write(out, prompt.data(), prompt.size());
+  std::string line;
+  bool got = false, eof = false;
+  char c;
+  while (true) {
+    ssize_t n = ::read(fd, &c, 1);
+    if (n <= 0) { eof = true; break; }
+    got = true;
+    if (c == '\n') break;
+    line.push_back(c);
+  }
+  if (changed) ::tcsetattr(fd, TCSAFLUSH, &old);
+  (void)!::write(out, "\n", 1);
+  if (own) ::close(fd);
+  if (eof && !got) return std::nullopt;  // EOFError
+  return line;
+}
+std::optional<std::string> Input(const std::string& prompt) {
+  std::fputs(prompt.c_str(), stdout);
+  std::fflush(stdout);
+  std::string line;
+  if (!std::getline(std::cin, line)) return std::nullopt;  // EOFError
+  return line;
+}
+}  // namespace
+
+std::unique_ptr<StreamSink> ShellIo::Stream(ShellApp& app, const std::string& command, bool live) {
+  if (app.HasStreamFactory()) return app.StreamFactory(app.Redact(command));
+  if (live && ::isatty(1)) return std::make_unique<LiveStream>();
+  return nullptr;
+}
+
+AskFn ShellIo::Ask(ShellApp& app, const std::string& command) {
+  if (app.Auto() || !app.Persist() || app.Depth() > 0) return nullptr;
+  ShellApp* a = &app;
+  auto answered = [a](std::optional<std::string> value) {
+    if (value) a->MarkUserSteppedIn();
+    return value;
+  };
+  if (app.HasPrompter()) {
+    std::string head = Utf8::Head(command, 60);
+    return [a, head, answered](const std::string& text, bool) { return answered(a->Prompt("ask", head + " asks:\n" + text, {})); };
+  }
+  if (!(::isatty(0) && ::isatty(1))) return nullptr;
+  return [answered](const std::string& text, bool secret) -> std::optional<std::string> {
+    std::string prompt = Paint("\xc2\xbb " + text + " ", Ansi::kYellow);
+    return answered(secret ? GetPass(prompt) : Input(prompt));
+  };
+}
+}  // namespace detz::shell