Implement @get-text

kitty/line-buf.c

@@ -383,7 +383,15 @@ as_ansi(LineBuf *self, PyObject *callback) {
 #define as_ansi_doc "as_ansi(callback) -> The contents of this buffer as ANSI escaped text. callback is called with each successive line."
     static Py_UCS4 t[5120];
     Line l = {.xnum=self->xnum};
-    for(index_type i = 0; i < self->ynum; i++) {
+    // remove trailing empty lines
+    index_type ylimit = self->ynum - 1;
+    do {
+        init_line(self, (&l), self->line_map[ylimit]);
+        if (line_as_ansi(&l, t, 5120) != 0) break;
+        ylimit--;
+    } while(ylimit > 0);
+
+    for(index_type i = 0; i <= ylimit; i++) {
         l.continued = ((i < self->ynum - 1) ? self->line_attrs[i+1] : self->line_attrs[i]) & CONTINUED_MASK;
         init_line(self, (&l), self->line_map[i]);
         index_type num = line_as_ansi(&l, t, 5120);

kitty/line.c

@@ -244,6 +244,7 @@ line_as_ansi(Line *self, Py_UCS4 *buf, index_type buflen) {
 #define WRITE_CH(val) if (i > buflen - 1) return i; buf[i++] = val;
 
     index_type limit = xlimit_for_line(self), i=0;
+    if (limit == 0) return 0;
     char_type previous_width = 0;
 
     WRITE_SGR("0");

kitty/remote_control.py

@@ -244,6 +244,49 @@ def new_window(boss, window, payload):
     return str(w.id)
 
 
+@cmd(
+    'Get text from the specified window',
+    options_spec=MATCH_WINDOW_OPTION + '''\n
+--extent
+default=screen
+choices=screen, all, selection
+What text to get. The default of screen means all text currently on the screen. all means
+all the screen+scrollback and selection means currently selected text.
+
+
+--ansi
+type=bool-set
+By default, only plain text is return. If you specify this flag, the text will
+include the formatting escape codes for colors/bold/italic/etc. Note that when
+getting the current selection, the result is always plain text.
+
+
+--self
+type=bool-set
+If specified get text from the window this command is run in, rather than the active window.
+'''
+)
+def cmd_get_text(global_opts, opts, args):
+    return {'match': opts.match, 'extent': opts.extent, 'ansi': opts.ansi, 'self': opts.self}
+
+
+def get_text(boss, window, payload):
+    match = payload['match']
+    if match:
+        windows = tuple(boss.match_windows(match))
+        if not windows:
+            raise ValueError('No matching windows for expression: {}'.format(match))
+    else:
+        windows = [window if window and payload['self'] else boss.active_window]
+    window = windows[0]
+    if payload['extent'] == 'selection':
+        ans = window.text_for_selection()
+    else:
+        f = window.buffer_as_ansi if payload['ansi'] else window.buffer_as_text
+        ans = f(add_history=payload['extent'] == 'all')
+    return ans
+
+
 cmap = {v.name: v for v in globals().values() if hasattr(v, 'is_cmd')}
 
 
@@ -270,12 +313,15 @@ global_options_spec = partial('''\
 
 def read_from_stdin(send, no_response):
     send = ('@kitty-cmd' + json.dumps(send)).encode('ascii')
-    if not sys.stdout.isatty():
+    out = sys.stdout if sys.stdout.isatty() else sys.stderr
-        raise SystemExit('stdout is not a terminal')
+    if not out.isatty():
-    sys.stdout.buffer.write(b'\x1bP' + send + b'\x1b\\')
+        raise SystemExit('Neither stdout nor stderr is a terminal')
-    sys.stdout.flush()
+    out.buffer.write(b'\x1bP' + send + b'\x1b\\')
+    out.flush()
     if no_response:
         return {'ok': True}
+    if not sys.stdin.isatty():
+        raise SystemExit('stdin is not a terminal')
 
     received = b''
     dcs = re.compile(br'\x1bP@kitty-cmd([^\x1b]+)\x1b\\')

kitty/window.py

@@ -312,14 +312,20 @@ class Window:
             self.screen.reset_callbacks()
         self.screen = None
 
-    def buffer_as_ansi(self):
+    def buffer_as_ansi(self, add_history=True):
         data = []
-        self.screen.historybuf.as_ansi(data.append)
+        if add_history:
+            self.screen.historybuf.as_ansi(data.append)
         self.screen.linebuf.as_ansi(data.append)
         return ''.join(data)
 
-    def buffer_as_text(self):
+    def buffer_as_text(self, add_history=True):
-        return str(self.screen.historybuf) + '\n' + str(self.screen.linebuf)
+        ans = str(self.screen.linebuf).rstrip('\n')
+        if add_history:
+            h = str(self.screen.historybuf)
+            if h.strip():
+                ans = h + '\n' + ans
+        return ans
 
     # actions {{{