Use gnome-screenshot on Linux if available

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 not Image.core.HAVE_XCB and 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")