int fd = ::open(filename.toFilesystemEncoding().c_str(),
O_WRONLY | O_NONBLOCK);
if (fd >= 0) {
// Another LyX instance is using it.
int fd = ::open(filename.toFilesystemEncoding().c_str(),
O_WRONLY | O_NONBLOCK);
if (fd >= 0) {
// Another LyX instance is using it.