Issue #13609: Add two functions to query the terminal size:

os.get_terminal_size (low level) and shutil.get_terminal_size (high level).
Patch by Zbigniew Jędrzejewski-Szmek.

1 files changed, 130 insertions, 0 deletions

diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 8b2b2117cb..0553c761bd 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -125,6 +125,18 @@ corresponding Unix manual entries for more information on calls.");
 #include <dlfcn.h>
 #endif
 
+#if defined(MS_WINDOWS)
+#  define TERMSIZE_USE_CONIO
+#elif defined(HAVE_SYS_IOCTL_H)
+#  include <sys/ioctl.h>
+#  if defined(HAVE_TERMIOS_H)
+#    include <termios.h>
+#  endif
+#  if defined(TIOCGWINSZ)
+#    define TERMSIZE_USE_IOCTL
+#  endif
+#endif /* MS_WINDOWS */
+
 /* Various compilers have only certain posix functions */
 /* XXX Gosh I wish these were all moved into pyconfig.h */
 #if defined(PYCC_VACPP) && defined(PYOS_OS2)
@@ -10477,6 +10489,114 @@ posix_flistxattr(PyObject *self, PyObject *args)
 
 #endif /* USE_XATTRS */
 
+
+/* Terminal size querying */
+
+static PyTypeObject TerminalSizeType;
+
+PyDoc_STRVAR(TerminalSize_docstring,
+    "A tuple of (columns, lines) for holding terminal window size");
+
+static PyStructSequence_Field TerminalSize_fields[] = {
+    {"columns", "width of the terminal window in characters"},
+    {"lines", "height of the terminal window in characters"},
+    {NULL, NULL}
+};
+
+static PyStructSequence_Desc TerminalSize_desc = {
+    "os.terminal_size",
+    TerminalSize_docstring,
+    TerminalSize_fields,
+    2,
+};
+
+#if defined(TERMSIZE_USE_CONIO) || defined(TERMSIZE_USE_IOCTL)
+PyDoc_STRVAR(termsize__doc__,
+    "Return the size of the terminal window as (columns, lines).\n"        \
+    "\n"                                                                   \
+    "The optional argument fd (default standard output) specifies\n"       \
+    "which file descriptor should be queried.\n"                           \
+    "\n"                                                                   \
+    "If the file descriptor is not connected to a terminal, an OSError\n"  \
+    "is thrown.\n"                                                         \
+    "\n"                                                                   \
+    "This function will only be defined if an implementation is\n"         \
+    "available for this system.\n"                                         \
+    "\n"                                                                   \
+    "shutil.get_terminal_size is the high-level function which should \n"  \
+    "normally be used, os.get_terminal_size is the low-level implementation.");
+
+static PyObject*
+get_terminal_size(PyObject *self, PyObject *args)
+{
+    int columns, lines;
+    PyObject *termsize;
+
+    int fd = fileno(stdout);
+    /* Under some conditions stdout may not be connected and
+     * fileno(stdout) may point to an invalid file descriptor. For example
+     * GUI apps don't have valid standard streams by default.
+     *
+     * If this happens, and the optional fd argument is not present,
+     * the ioctl below will fail returning EBADF. This is what we want.
+     */
+
+    if (!PyArg_ParseTuple(args, "|i", &fd))
+        return NULL;
+
+#ifdef TERMSIZE_USE_IOCTL
+    {
+        struct winsize w;
+        if (ioctl(fd, TIOCGWINSZ, &w))
+            return PyErr_SetFromErrno(PyExc_OSError);
+        columns = w.ws_col;
+        lines = w.ws_row;
+    }
+#endif /* TERMSIZE_USE_IOCTL */
+
+#ifdef TERMSIZE_USE_CONIO
+    {
+        DWORD nhandle;
+        HANDLE handle;
+        CONSOLE_SCREEN_BUFFER_INFO csbi;
+        switch (fd) {
+        case 0: nhandle = STD_INPUT_HANDLE;
+            break;
+        case 1: nhandle = STD_OUTPUT_HANDLE;
+            break;
+        case 2: nhandle = STD_ERROR_HANDLE;
+            break;
+        default:
+            return PyErr_Format(PyExc_ValueError, "bad file descriptor");
+        }
+        handle = GetStdHandle(nhandle);
+        if (handle == NULL)
+            return PyErr_Format(PyExc_OSError, "handle cannot be retrieved");
+        if (handle == INVALID_HANDLE_VALUE)
+            return PyErr_SetFromWindowsErr(0);
+
+        if (!GetConsoleScreenBufferInfo(handle, &csbi))
+            return PyErr_SetFromWindowsErr(0);
+
+        columns = csbi.srWindow.Right - csbi.srWindow.Left + 1;
+        lines = csbi.srWindow.Bottom - csbi.srWindow.Top + 1;
+    }
+#endif /* TERMSIZE_USE_CONIO */
+
+    termsize = PyStructSequence_New(&TerminalSizeType);
+    if (termsize == NULL)
+        return NULL;
+    PyStructSequence_SET_ITEM(termsize, 0, PyLong_FromLong(columns));
+    PyStructSequence_SET_ITEM(termsize, 1, PyLong_FromLong(lines));
+    if (PyErr_Occurred()) {
+        Py_DECREF(termsize);
+        return NULL;
+    }
+    return termsize;
+}
+#endif /* defined(TERMSIZE_USE_CONIO) || defined(TERMSIZE_USE_IOCTL) */
+
+
 static PyMethodDef posix_methods[] = {
     {"access",          posix_access, METH_VARARGS, posix_access__doc__},
 #ifdef HAVE_TTYNAME
@@ -10945,6 +11065,9 @@ static PyMethodDef posix_methods[] = {
     {"llistxattr", posix_llistxattr, METH_VARARGS, posix_llistxattr__doc__},
     {"flistxattr", posix_flistxattr, METH_VARARGS, posix_flistxattr__doc__},
 #endif
+#if defined(TERMSIZE_USE_CONIO) || defined(TERMSIZE_USE_IOCTL)
+    {"get_terminal_size", get_terminal_size, METH_VARARGS, termsize__doc__},
+#endif
     {NULL,              NULL}            /* Sentinel */
 };
 
@@ -11539,6 +11662,10 @@ INITFUNC(void)
         PyStructSequence_InitType(&SchedParamType, &sched_param_desc);
         SchedParamType.tp_new = sched_param_new;
 #endif
+
+        /* initialize TerminalSize_info */
+        PyStructSequence_InitType(&TerminalSizeType, &TerminalSize_desc);
+        Py_INCREF(&TerminalSizeType);
     }
 #if defined(HAVE_WAITID) && !defined(__APPLE__)
     Py_INCREF((PyObject*) &WaitidResultType);
@@ -11593,6 +11720,9 @@ INITFUNC(void)
 
 
 #endif /* __APPLE__ */
+
+    PyModule_AddObject(m, "terminal_size", (PyObject*) &TerminalSizeType);
+
     return m;
 
 }