tai/taicpp/src/shell/ptyproc.cpp

#include "ptyproc.h"
#include <cerrno>
#include <cstdlib>
#include <fcntl.h>
#include <poll.h>
#include <sys/ioctl.h>
#include <termios.h>
#include <unistd.h>
namespace detz::shell {
bool PtyProc::Available() { return true; }

PtyProc::PtyProc(const std::vector<std::string>& argv, const std::optional<std::string>& shellCommand, const std::optional<std::string>& cwd, const EnvMap* env, int rows, int cols) {
  int master = ::posix_openpt(O_RDWR | O_NOCTTY);
  if (master < 0) throw OsError(errno, "");
  if (::grantpt(master) != 0 || ::unlockpt(master) != 0) { int e = errno; ::close(master); throw OsError(e, ""); }
  char name[128];
  if (::ptsname_r(master, name, sizeof name) != 0) { int e = errno; ::close(master); throw OsError(e, ""); }
  int slave = ::open(name, O_RDWR | O_NOCTTY);
  if (slave < 0) { int e = errno; ::close(master); throw OsError(e, ""); }
  ::fcntl(master, F_SETFD, FD_CLOEXEC);
  try {
    struct winsize ws = {};
    ws.ws_row = (unsigned short)rows; ws.ws_col = (unsigned short)cols;
    ::ioctl(master, TIOCSWINSZ, &ws);
    PopenOptions o;
    o.argv = argv;
    o.shellCommand = shellCommand;
    o.cwd = cwd;
    o.env = env;
    o.in = o.out = o.err = StdMode::Fd;
    o.inFd = o.outFd = o.errFd = slave;
    o.adoptCtty = true;
    proc_ = std::make_unique<Popen>(o);
  } catch (...) {
    ::close(slave);
    ::close(master);
    throw;
  }
  ::close(slave);
  master_ = master;
}
PtyProc::~PtyProc() { Close(); }

PtyProc::ReadResult PtyProc::Read(double timeoutSeconds) {
  ReadResult r;
  struct pollfd pfd = {master_, POLLIN, 0};
  int ms = (int)(std::max(0.0, timeoutSeconds) * 1000.0);
  int rc;
  do { rc = ::poll(&pfd, 1, ms); } while (rc < 0 && errno == EINTR);
  if (rc <= 0) return r;  // select() reported nothing readable
  char buf[65536];
  ssize_t n;
  do { n = ::read(master_, buf, sizeof buf); } while (n < 0 && errno == EINTR);
  if (n <= 0) { r.kind = ReadKind::End; return r; }  // EOF, or OSError (EIO) once the slave closed
  r.kind = ReadKind::Data;
  r.data.assign(buf, (size_t)n);
  return r;
}
void PtyProc::Write(const std::string& text) { WriteBytes(text); }
void PtyProc::WriteBytes(const std::string& data) {
  size_t off = 0;
  while (off < data.size()) {
    ssize_t n = ::write(master_, data.data() + off, data.size() - off);
    if (n < 0) { if (errno == EINTR) continue; throw OsError(errno, ""); }
    off += (size_t)n;
  }
}
void PtyProc::Resize(int rows, int cols) {
  struct winsize ws = {};
  ws.ws_row = (unsigned short)rows; ws.ws_col = (unsigned short)cols;
  if (::ioctl(master_, TIOCSWINSZ, &ws) != 0) throw OsError(errno, "");
}
bool PtyProc::EchoOff() const {
  struct termios t;
  if (::tcgetattr(master_, &t) != 0) return false;
  return !(t.c_lflag & ECHO);
}
void PtyProc::Kill() { if (proc_) proc_->KillGroup(); }
void PtyProc::Close() { if (master_ >= 0) { ::close(master_); master_ = -1; } }
}  // namespace detz::shell