Fix clipboard hang caused by xclip background process.

Add clipboard.py module to work around pyperclip bug where xclip
operations hang indefinitely. The issue occurs because xclip forks
into the background to serve clipboard requests, but pyperclip calls
subprocess.communicate() which waits for the process to exit.

Solution: On Linux with X11, call xclip directly without waiting for
exit. Write to stdin and close it, then return immediately while
xclip forks to background. Fall back to pyperclip on other platforms.

Update create.py, apply.py, and prompt.py to use new clipboard module
instead of calling pyperclip directly.

Related: asweigart/pyperclip#247

Co-Authored-By: Claude Sonnet 4.5 <[email protected]>

Author: emcd

sources/mimeogram/apply.py

@@ -134,8 +134,8 @@ def stdin_is_tty( self ) -> bool:
         return __.sys.stdin.isatty( )
 
     async def acquire_clipboard( self ) -> str:
-        from pyperclip import paste
-        return paste( )
+        from . import clipboard
+        return clipboard.copy_from_clipboard( )
 
     async def acquire_file( self, path: str | __.Path ) -> str:
         return await __.appcore.io.acquire_text_file_async( path )

sources/mimeogram/clipboard.py

@@ -0,0 +1,84 @@
+# vim: set filetype=python fileencoding=utf-8:
+# -*- coding: utf-8 -*-
+
+#============================================================================#
+#                                                                            #
+#  Licensed under the Apache License, Version 2.0 (the "License");           #
+#  you may not use this file except in compliance with the License.          #
+#  You may obtain a copy of the License at                                   #
+#                                                                            #
+#      http://www.apache.org/licenses/LICENSE-2.0                            #
+#                                                                            #
+#  Unless required by applicable law or agreed to in writing, software       #
+#  distributed under the License is distributed on an "AS IS" BASIS,         #
+#  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.  #
+#  See the License for the specific language governing permissions and       #
+#  limitations under the License.                                            #
+#                                                                            #
+#============================================================================#
+
+
+# Clipboard operations module.
+#
+# This module exists to work around a bug in pyperclip where calling
+# subprocess.communicate() on xclip causes the process to hang indefinitely.
+# xclip forks into the background to serve clipboard paste requests and never
+# exits, but pyperclip waits for it to exit. The same bug exists in pyclip.
+#
+# See: https://github.com/asweigart/pyperclip/issues/247
+#
+# Our solution: Call xclip directly on Linux/X11 without waiting for exit.
+# Fall back to pyperclip on other platforms (may still hang on some systems).
+
+
+''' Clipboard operations. '''
+
+
+import subprocess as _subprocess
+
+from . import __
+
+
+_scribe = __.produce_scribe( __name__ )
+
+
+def copy_to_clipboard( text: str ) -> None:
+    ''' Copies text to clipboard. '''
+    # Try xclip first on Linux with X11
+    if __.sys.platform == 'linux' and __.os.environ.get( 'DISPLAY' ):
+        try:
+            # Use xclip directly, don't wait for it to finish
+            # xclip forks into background and stays running to serve pastes
+            proc = _subprocess.Popen(
+                [ 'xclip', '-selection', 'clipboard' ],  # noqa: S607
+                stdin = _subprocess.PIPE,
+                stdout = _subprocess.DEVNULL,
+                stderr = _subprocess.DEVNULL,
+                close_fds = True,
+            )
+        except FileNotFoundError:
+            _scribe.debug( "xclip not found, falling back to pyperclip" )
+        except Exception as exc:
+            _scribe.warning(
+                f"xclip failed ({exc}), falling back to pyperclip" )
+        else:
+            assert proc.stdin is not None  # noqa: S101
+            proc.stdin.write( text.encode( 'utf-8' ) )
+            proc.stdin.close( )
+            # Don't call proc.wait() or proc.communicate() - let xclip fork
+            _scribe.debug( "Copied to clipboard via xclip" )
+            return
+    # Fall back to pyperclip for other platforms or if xclip fails
+    from pyperclip import copy
+    try:
+        copy( text )
+    except Exception as exc:
+        _scribe.error( f"Failed to copy to clipboard: {exc}" )
+        raise
+    _scribe.debug( "Copied to clipboard via pyperclip" )
+
+
+def copy_from_clipboard( ) -> str:
+    ''' Copies text from clipboard. '''
+    from pyperclip import paste
+    return paste( )

sources/mimeogram/create.py

@@ -153,8 +153,8 @@ async def _acquire_prompt(
 
 
 async def _copy_to_clipboard( mimeogram: str ) -> None:
-    from pyperclip import copy
-    copy( mimeogram )
+    from . import clipboard
+    clipboard.copy_to_clipboard( mimeogram )
     _scribe.info( "Copied mimeogram to clipboard." )
 
 

sources/mimeogram/prompt.py

@@ -79,10 +79,10 @@ async def provide_prompt(
         prompt = await acquire_prompt( auxdata )
     options = auxdata.configuration.get( 'prompt', { } )
     if options.get( 'to-clipboard', False ):
-        from pyperclip import copy
+        from . import clipboard
         with _exceptions.report_exceptions(
             _scribe, "Could not copy prompt to clipboard."
-        ): copy( prompt )
+        ): clipboard.copy_to_clipboard( prompt )
         _scribe.info( "Copied prompt to clipboard." )
     else: print( prompt ) # TODO? Use output stream from configuration.
     raise SystemExit( 0 )