bpo-41818: Add termios.tcgetwinsize(), termios.tcsetwinsize(). Update docs.

Doc/library/termios.rst

@@ -74,6 +74,22 @@ The module defines the following functions:
  output, :const:`TCIOFF` to suspend input, or :const:`TCION` to restart input.
 
 
+.. function:: tcgetwinsize(fd)
+
+ Return a tuple ``(ws_row, ws_col)`` containing the tty window size for file
+ descriptor *fd*. Requires :const:`termios.TIOCGWINSZ` or
+ :const:`termios.TIOCGSIZE`.
+
+
+.. function:: tcsetwinsize(fd, winsize)
+
+ Set the tty window size for file descriptor *fd* from *winsize*, which is
+ a two-item tuple ``(ws_row, ws_col)`` like the one returned by
+ :func:`tcgetwinsize`. Requires at least one of the pairs
+ (:const:`termios.TIOCGWINSZ`, :const:`termios.TIOCSWINSZ`);
+ (:const:`termios.TIOCGSIZE`, :const:`termios.TIOCSSIZE`) to be defined.
+
+
 .. seealso::
 
  Module :mod:`tty`

Misc/NEWS.d/next/Library/2020-12-08-01-08-58.bpo-41818.zO8vV7.rst

@@ -0,0 +1 @@
+Soumendra Ganguly: add termios.tcgetwinsize(), termios.tcsetwinsize().

Modules/termios.c

@@ -315,6 +315,156 @@ termios_tcflow_impl(PyObject *module, int fd, int action)
  Py_RETURN_NONE;
 }
 
+/*[clinic input]
+termios.tcgetwinsize
+
+ fd: fildes
+ /
+
+Get the tty winsize for file descriptor fd.
+
+Returns a tuple (ws_row, ws_col).
+[clinic start generated code]*/
+
+static PyObject *
+termios_tcgetwinsize_impl(PyObject *module, int fd)
+/*[clinic end generated code: output=31825977d5325fb6 input=5706c379d7fd984d]*/
+{
+#if defined(TIOCGWINSZ)
+ termiosmodulestate *state = PyModule_GetState(module);
+ struct winsize w;
+ if (ioctl(fd, TIOCGWINSZ, &w) == -1) {
+ return PyErr_SetFromErrno(state->TermiosError);
+ }
+
+ PyObject *v;
+ if (!(v = PyTuple_New(2))) {
+ return NULL;
+ }
+
+ PyTuple_SetItem(v, 0, PyLong_FromLong((long)w.ws_row));
+ PyTuple_SetItem(v, 1, PyLong_FromLong((long)w.ws_col));
+ if (PyErr_Occurred()) {
+ Py_DECREF(v);
+ return NULL;
+ }
+ return v;
+#elif defined(TIOCGSIZE)
+ termiosmodulestate *state = PyModule_GetState(module);
+ struct ttysize s;
+ if (ioctl(fd, TIOCGSIZE, &s) == -1) {
+ return PyErr_SetFromErrno(state->TermiosError);
+ }
+
+ PyObject *v;
+ if (!(v = PyTuple_New(2))) {
+ return NULL;
+ }
+
+ PyTuple_SetItem(v, 0, PyLong_FromLong((long)s.ts_lines));
+ PyTuple_SetItem(v, 1, PyLong_FromLong((long)s.ts_cols));
+ if (PyErr_Occurred()) {
+ Py_DECREF(v);
+ return NULL;
+ }
+ return v;
+#else
+ PyErr_SetString(PyExc_NotImplementedError,
+ "requires termios.TIOCGWINSZ and/or termios.TIOCGSIZE");
+ return NULL;
+#endif /* defined(TIOCGWINSZ) */
+}
+
+/*[clinic input]
+termios.tcsetwinsize
+
+ fd: fildes
+ winsize as winsz: object
+ /
+
+Set the tty winsize for file descriptor fd.
+
+The winsize to be set is taken from the winsize argument, which
+is a two-item tuple (ws_row, ws_col) like the one returned by tcgetwinsize().
+[clinic start generated code]*/
+
+static PyObject *
+termios_tcsetwinsize_impl(PyObject *module, int fd, PyObject *winsz)
+/*[clinic end generated code: output=2ac3c9bb6eda83e1 input=4a06424465b24aee]*/
+{
+ if (!PySequence_Check(winsz) || PySequence_Size(winsz) != 2) {
+ PyErr_SetString(PyExc_TypeError,
+ "tcsetwinsize, arg 2: must be a two-item sequence");
+ return NULL;
+ }
+
+ PyObject *tmp_item;
+ long winsz_0, winsz_1;
+ tmp_item = PySequence_GetItem(winsz, 0);
+ winsz_0 = PyLong_AsLong(tmp_item);
+ if (winsz_0 == -1 && PyErr_Occurred()) {
+ Py_XDECREF(tmp_item);
+ return NULL;
+ }
+ Py_XDECREF(tmp_item);
+ tmp_item = PySequence_GetItem(winsz, 1);
+ winsz_1 = PyLong_AsLong(tmp_item); 
+ if (winsz_1 == -1 && PyErr_Occurred()) {
+ Py_XDECREF(tmp_item);
+ return NULL;
+ }
+ Py_XDECREF(tmp_item);
+
+ termiosmodulestate *state = PyModule_GetState(module);
+
+#if defined(TIOCGWINSZ) && defined(TIOCSWINSZ)
+ struct winsize w;
+ /* Get the old winsize because it might have
+ more fields such as xpixel, ypixel. */
+ if (ioctl(fd, TIOCGWINSZ, &w) == -1) {
+ return PyErr_SetFromErrno(state->TermiosError);
+ }
+
+ w.ws_row = (unsigned short) winsz_0;
+ w.ws_col = (unsigned short) winsz_1;
+ if ((((long)w.ws_row) != winsz_0) || (((long)w.ws_col) != winsz_1)) {
+ PyErr_SetString(PyExc_OverflowError,
+ "winsize value(s) out of range.");
+ return NULL;
+ }
+
+ if (ioctl(fd, TIOCSWINSZ, &w) == -1) {
+ return PyErr_SetFromErrno(state->TermiosError);
+ }
+
+ Py_RETURN_NONE;
+#elif defined(TIOCGSIZE) && defined(TIOCSSIZE)
+ struct ttysize s;
+ /* Get the old ttysize because it might have more fields. */
+ if (ioctl(fd, TIOCGSIZE, &s) == -1) {
+ return PyErr_SetFromErrno(state->TermiosError);
+ }
+
+ s.ts_lines = (int) winsz_0;
+ s.ts_cols = (int) winsz_1;
+ if ((((long)s.ts_lines) != winsz_0) || (((long)s.ts_cols) != winsz_1)) {
+ PyErr_SetString(PyExc_OverflowError,
+ "winsize value(s) out of range.");
+ return NULL;
+ }
+
+ if (ioctl(fd, TIOCSSIZE, &s) == -1) {
+ return PyErr_SetFromErrno(state->TermiosError);
+ }
+
+ Py_RETURN_NONE;
+#else
+ PyErr_SetString(PyExc_NotImplementedError,
+ "requires termios.TIOCGWINSZ, termios.TIOCSWINSZ and/or termios.TIOCGSIZE, termios.TIOCSSIZE");
+ return NULL;
+#endif /* defined(TIOCGWINSZ) && defined(TIOCSWINSZ) */
+}
+
 static PyMethodDef termios_methods[] =
 {
  TERMIOS_TCGETATTR_METHODDEF
@@ -323,6 +473,8 @@ static PyMethodDef termios_methods[] =
  TERMIOS_TCDRAIN_METHODDEF
  TERMIOS_TCFLUSH_METHODDEF
  TERMIOS_TCFLOW_METHODDEF
+ TERMIOS_TCGETWINSIZE_METHODDEF
+ TERMIOS_TCSETWINSIZE_METHODDEF
  {NULL, NULL}
 };
 
@@ -841,6 +993,9 @@ static struct constant {
 #ifdef TIOCGSERIAL
  {"TIOCGSERIAL", TIOCGSERIAL},
 #endif
+#ifdef TIOCGSIZE
+ {"TIOCGSIZE", TIOCGSIZE},
+#endif
 #ifdef TIOCGSOFTCAR
  {"TIOCGSOFTCAR", TIOCGSOFTCAR},
 #endif
@@ -973,6 +1128,9 @@ static struct constant {
 #ifdef TIOCSSERIAL
  {"TIOCSSERIAL", TIOCSSERIAL},
 #endif
+#ifdef TIOCSSIZE
+ {"TIOCSSIZE", TIOCSSIZE},
+#endif
 #ifdef TIOCSSOFTCAR
  {"TIOCSSOFTCAR", TIOCSSOFTCAR},
 #endif