Function __syscall_ioctl

system/lib/wasmfs/syscalls.cpp:1316–1364

}

int __syscall_ioctl(int fd, int request, ...) {
  auto openFile = wasmFS.getFileTable().locked().getEntry(fd);
  if (!openFile) {
    return -EBADF;
  }

  va_list args;
  va_start(args, request);
  void* argp = va_arg(args, void*);
  va_end(args);

  auto openHandle = openFile->locked();
  auto file = openHandle.getFile();

  if (request == FIONREAD) {
    off_t size = file->locked().getSize();
    if (size < 0) {
      return (int)size;
    }
    if (file->isSeekable()) {
      size -= openHandle.getPosition();
    }
    *static_cast<int*>(argp) = static_cast<int>(size);
    return 0;
  }

  if (!isTTY(file)) {
    return -ENOTTY;
  }
  // TODO: Full TTY support. For now this is limited, and matches the old FS.
  switch (request) {
    case TCGETA:
    case TCGETS:
    case TCSETA:
    case TCSETAW:
    case TCSETAF:
    case TCSETS:
    case TCSETSW:
    case TCSETSF:
    case TIOCGWINSZ:
    case TIOCSWINSZ: {
      // TTY operations that we do nothing for anyhow can just be ignored.
      return 0;
    }
    default: {
      return -EINVAL; // not supported
    }
  }
}

int __syscall_pipe2(int fd[2], int flags) {
  auto* fds = (__wasi_fd_t*)fd;