Use gnome-screenshot on Linux if available

docs/reference/ImageGrab.rst

@@ -15,7 +15,10 @@ or the clipboard to a PIL image memory.
     returned as an "RGBA" on macOS, or an "RGB" image otherwise.
     If the bounding box is omitted, the entire screen is copied.
 
-    .. versionadded:: 1.1.3 (Windows), 3.0.0 (macOS), 7.1.0 (Linux (X11))
+    On Linux, if ``xdisplay`` is ``None`` then ``gnome-screenshot`` will be used if it
+    is installed. To capture the default X11 display instead, pass ``xdisplay=""``.
+
+    .. versionadded:: 1.1.3 (Windows), 3.0.0 (macOS), 7.1.0 (Linux)
 
     :param bbox: What region to copy. Default is the entire screen.
                  Note that on Windows OS, the top-left point may be negative if ``all_screens=True`` is used.

docs/releasenotes/9.2.0.rst

@@ -76,7 +76,9 @@ TODO
 Other Changes
 =============
 
-TODO
-^^^^
+Using gnome-screenshot on Linux
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-TODO
+In :py:meth:`~PIL.ImageGrab.grab` on Linux, if ``xdisplay`` is ``None`` then
+``gnome-screenshot`` will be used to capture the display if it is installed. To capture
+the default X11 display instead, pass ``xdisplay=""``.

src/PIL/ImageGrab.py

@@ -15,15 +15,14 @@
 # See the README file for information on usage and redistribution.
 #
 
+import os
+import shutil
+import subprocess
 import sys
+import tempfile
 
 from . import Image
 
-if sys.platform == "darwin":
-    import os
-    import subprocess
-    import tempfile
-
 
 def grab(bbox=None, include_layered_windows=False, all_screens=False, xdisplay=None):
     if xdisplay is None:
@@ -62,6 +61,18 @@ def grab(bbox=None, include_layered_windows=False, all_screens=False, xdisplay=N
                 left, top, right, bottom = bbox
                 im = im.crop((left - x0, top - y0, right - x0, bottom - y0))
             return im
+        elif shutil.which("gnome-screenshot"):
+            fh, filepath = tempfile.mkstemp(".png")
+            os.close(fh)
+            subprocess.call(["gnome-screenshot", "-f", filepath])
+            im = Image.open(filepath)
+            im.load()
+            os.unlink(filepath)
+            if bbox:
+                im_cropped = im.crop(bbox)
+                im.close()
+                return im_cropped
+            return im
     # use xdisplay=None for default display on non-win32/macOS systems
     if not Image.core.HAVE_XCB:
         raise OSError("Pillow was built without XCB support")