Linux: Add an option to cause calibre to detach from its controlling terminal

src/calibre/gui2/__init__.py

@@ -803,6 +803,20 @@ def load_builtin_fonts():
                     if u'calibre Symbols' in fam:
                         _rating_font = u'calibre Symbols'
 
+def setup_gui_option_parser(parser):
+    if islinux:
+        parser.add_option('--detach', default=False, action='store_true',
+                          help='Detach from the controlling terminal, if any (linux only)')
+
+def detach_gui():
+    if islinux and not DEBUG and sys.stdout.isatty():
+        # We are a GUI process running in a terminal so detach from the controlling terminal
+        if os.fork() != 0:
+            raise SystemExit(0)
+        os.setsid()
+        so, se = file(os.devnull, 'a+'), file(os.devnull, 'a+', 0)
+        os.dup2(so.fileno(), sys.__stdout__.fileno())
+        os.dup2(se.fileno(), sys.__stderr__.fileno())
 
 class Application(QApplication):
 
@@ -824,7 +838,6 @@ class Application(QApplication):
         self._file_open_paths = []
         self._file_open_lock = RLock()
         self.setup_styles(force_calibre_style)
-
     if DEBUG:
         def notify(self, receiver, event):
             if self.redirect_notify:

src/calibre/gui2/main.py

@@ -12,8 +12,9 @@ from calibre import prints, plugins, force_unicode
 from calibre.constants import (iswindows, __appname__, isosx, DEBUG, islinux,
         filesystem_encoding, get_portable_base)
 from calibre.utils.ipc import gui_socket_address, RC
-from calibre.gui2 import (ORG_NAME, APP_UID, initialize_file_icon_provider,
-    Application, choose_dir, error_dialog, question_dialog, gprefs)
+from calibre.gui2 import (
+    ORG_NAME, APP_UID, initialize_file_icon_provider, Application, choose_dir,
+    error_dialog, question_dialog, gprefs, detach_gui, setup_gui_option_parser)
 from calibre.gui2.main_window import option_parser as _option_parser
 from calibre.utils.config import prefs, dynamic
 
@@ -46,6 +47,7 @@ path_to_ebook to the database.
             help=_('Cause a running calibre instance, if any, to be'
                 ' shutdown. Note that if there are running jobs, they '
                 'will be silently aborted, so use with care.'))
+    setup_gui_option_parser(parser)
     return parser
 
 def find_portable_library():
@@ -84,6 +86,8 @@ def find_portable_library():
 def init_qt(args):
     parser = option_parser()
     opts, args = parser.parse_args(args)
+    if getattr(opts, 'detach', False):
+        detach_gui()
     find_portable_library()
     if opts.with_library is not None:
         libpath = os.path.expanduser(opts.with_library)

src/calibre/gui2/tweak_book/main.py

@@ -11,17 +11,20 @@ import sys, os
 from PyQt4.Qt import QIcon
 
 from calibre.constants import islinux
-from calibre.gui2 import Application, ORG_NAME, APP_UID
+from calibre.gui2 import Application, ORG_NAME, APP_UID, setup_gui_option_parser, detach_gui
 from calibre.ptempfile import reset_base_dir
 from calibre.utils.config import OptionParser
 from calibre.gui2.tweak_book.ui import Main
 
 def option_parser():
-    return OptionParser('''\
+    parser =  OptionParser('''\
 %prog [opts] [path_to_ebook]
 
 Launch the calibre tweak book tool.
 ''')
+    setup_gui_option_parser(parser)
+    return parser
+
 
 def main(args=sys.argv):
     # Ensure we can continue to function if GUI is closed
@@ -30,6 +33,8 @@ def main(args=sys.argv):
 
     parser = option_parser()
     opts, args = parser.parse_args(args)
+    if getattr(opts, 'detach', False):
+        detach_gui()
     override = 'calibre-tweak-book' if islinux else None
     app = Application(args, override_program_name=override)
     app.load_builtin_fonts()

src/calibre/gui2/viewer/main.py

@@ -18,7 +18,7 @@ from calibre.gui2.viewer.toc import TOC
 from calibre.gui2.widgets import ProgressIndicator
 from calibre.gui2.main_window import MainWindow
 from calibre.gui2 import (Application, ORG_NAME, APP_UID, choose_files,
-    info_dialog, error_dialog, open_url, available_height)
+    info_dialog, error_dialog, open_url, available_height, setup_gui_option_parser, detach_gui)
 from calibre.ebooks.oeb.iterator.book import EbookIterator
 from calibre.ebooks import DRMError
 from calibre.constants import islinux, filesystem_encoding
@@ -1183,11 +1183,13 @@ def config(defaults=None):
 
 def option_parser():
     c = config()
-    return c.option_parser(usage=_('''\
+    parser = c.option_parser(usage=_('''\
 %prog [options] file
 
 View an ebook.
 '''))
+    setup_gui_option_parser(parser)
+    return parser
 
 
 def main(args=sys.argv):
@@ -1197,6 +1199,8 @@ def main(args=sys.argv):
 
     parser = option_parser()
     opts, args = parser.parse_args(args)
+    if getattr(opts, 'detach', False):
+        detach_gui()
     try:
         open_at = float(opts.open_at)
     except: