Make the clipboard command user-configurable

Add config item clipboard_cmd, with a default of 'pbcopy w' on Darwin
and 'xclip' on everything else. This will allow the user to use any
command for the clipboard, including 'wl-copy' for Wayland (addressing
issue #693 on Github). With his change, significant simplifications
could be made to clipboard.py - the copy_*() functions have been removed
and combined into copy().

With this simplification, the old OSX test is obsolete, and new OSX
tests are needed (need a way to simulate sys.platform).

rtv/clipboard.py

@@ -4,48 +4,22 @@ from __future__ import unicode_literals
 import sys
 import subprocess
 
-from .exceptions import ProgramError
-
-
 def _subprocess_copy(text, args_list):
     p = subprocess.Popen(args_list, stdin=subprocess.PIPE, close_fds=True)
     p.communicate(input=text.encode('utf-8'))
 
 
-def copy(text):
+def copy(text, cmd):
     """
     Copy text to OS clipboard.
     """
 
-    if sys.platform == 'darwin':
-        copy_osx(text)
-    else:
-        # For Linux, BSD, cygwin, etc.
-        copy_linux(text)
+    # If no command is specified (i.e. the config option is empty) try
+    # to find a reasonable default based on the operating system
+    if cmd is None:
+        if sys.platform == 'darwin':
+            cmd = 'pbcopy w'
+        else: # For Linux, BSD, cygwin, etc.
+            cmd = 'xclip'
 
-
-def copy_osx(text):
-    _subprocess_copy(text, ['pbcopy', 'w'])
-
-
-def copy_linux(text):
-
-    def get_command_name():
-        # Checks for the installation of xsel or xclip
-        for cmd in ['xsel', 'xclip']:
-            cmd_exists = subprocess.call(
-                ['which', cmd],
-                stdout=subprocess.PIPE, stderr=subprocess.PIPE) == 0
-            if cmd_exists:
-                return cmd
-        return None
-
-    cmd_args = {
-        'xsel': ['xsel', '-b', '-i'],
-        'xclip': ['xclip', '-selection', 'c']}
-    cmd_name = get_command_name()
-
-    if cmd_name is None:
-        raise ProgramError("External copy application not found")
-
-    _subprocess_copy(text, cmd_args.get(cmd_name))
+    _subprocess_copy(text, cmd.split())

rtv/page.py

@@ -542,7 +542,7 @@ class Page(object):
             return
 
         try:
-            clipboard_copy(url)
+            clipboard_copy(url, self.config['clipboard_cmd'])
         except (ProgramError, OSError) as e:
             _logger.exception(e)
             self.term.show_notification(

rtv/templates/rtv.cfg

@@ -16,6 +16,12 @@ ascii = False
 ; Turn on monochrome mode to disable color.
 monochrome = False
 
+; Data being copied is piped into this command
+;clipboard_cmd = xclip
+;clipboard_cmd = xsel -b -i
+;clipboard_cmd = wl-copy
+;clipboard_cmd = pbcopy w
+
 ; Flash when an invalid action is executed.
 flash = True