编辑

经过一些工作，我写了一个比下面更完整，更易于使用的解决方案。您可以在GitHub上下载该程序。您还需要安装依赖项：

sudo apt install xdotool xprintidle

原始答案

在Jacob Vlijm向我指出了部分解决方案之后，我将他的脚本的修改版本与部分Caffeine和我自己的一些代码组合在一起，并提出了Caffeine的替代品。

指示

1. 确保安装了必要的软件包。注意：caffeine-plus仅用于图标。如果您不关心适当的图标，则不需要它。

   sudo apt install caffeine-plus xprintidle xdotool
   

2. 将以下脚本保存在某个地方，使其可执行。

   #!/usr/bin/python3
   # coding=utf-8
   #
   # Copyright © 2016 Scott Severance
   # Code mixed in from Caffeine Plus and Jacob Vlijm
   #
   # This program is free software: you can redistribute it and/or modify
   # it under the terms of the GNU General Public License as published by
   # the Free Software Foundation, either version 3 of the License, or
   # (at your option) any later version.
   #
   # This program is distributed in the hope that it will be useful,
   # but WITHOUT ANY WARRANTY; without even the implied warranty of
   # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   # GNU General Public License for more details.
   #
   # You should have received a copy of the GNU General Public License
   # along with this program.  If not, see <http://www.gnu.org/licenses/>.
   
   import argparse
   import os
   import signal
   import time
   from subprocess import Popen, check_output, call
   import gi
   gi.require_version('Gtk', '3.0')
   gi.require_version('AppIndicator3', '0.1')
   from gi.repository import GObject, Gtk, AppIndicator3
   
   class SleepInhibit(GObject.GObject):
   
       def __init__(self):
           GObject.GObject.__init__(self)
           self.inhibited = False
           self._add_indicator()
           self.inhibit_proc = None
   
       def _add_indicator(self):
           self.AppInd = AppIndicator3.Indicator.new("sleep-inhibit-off",
                                                     "sleep-inhibit",
                                                     AppIndicator3.IndicatorCategory.APPLICATION_STATUS)
           self.AppInd.set_status(AppIndicator3.IndicatorStatus.ACTIVE)
           self.AppInd.set_icon ("caffeine-cup-empty")
   
           self._build_indicator_menu(self.AppInd)
   
       def _build_indicator_menu(self, indicator):
           menu = Gtk.Menu()
   
           menu_item = Gtk.MenuItem("Toggle Sleep Inhibition")
           menu.append(menu_item)
           menu_item.connect("activate", self.on_toggle)
           menu_item.show()
   
           menu_item = Gtk.MenuItem("Quit")
           menu.append(menu_item)
           menu_item.connect("activate", self.on_quit)
           menu_item.show()
   
           indicator.set_menu(menu)
   
       def on_toggle(self, menuitem):
           self.inhibited = not self.inhibited
           self.flip_switch()
   
       def on_quit(self, menuitem):
           if self.inhibit_proc:
               self.kill_inhibit_proc()
           exit(0)
   
       def _set_icon_disabled(self):
           self.AppInd.set_icon('caffeine-cup-empty')
   
       def _set_icon_enabled(self):
           self.AppInd.set_icon('caffeine-cup-full')
   
       def flip_switch(self):
           if self.inhibited:
               self._set_icon_enabled()
               self.inhibit_proc = Popen([__file__, "--mode=inhibit-process"])
           else:
               self.kill_inhibit_proc()
               self._set_icon_disabled()
   
       def kill_inhibit_proc(self):
           self.inhibit_proc.terminate()
           self.inhibit_proc.wait()
           self.inhibit_proc = None
   
   def inhibit():
       seconds = 120 # number of seconds to start preventing blank screen / suspend
       while True:
           try:
               curr_idle = check_output(["xprintidle"]).decode("utf-8").strip()
               if int(curr_idle) > seconds*1000:
                   call(["xdotool", "key", "Control_L"])
               time.sleep(10)
           except FileNotFoundError:
               exit('ERROR: This program depends on xprintidle and xdotool being installed.')
           except KeyboardInterrupt:
               exit(0)
   
   def parse_args():
       parser = argparse.ArgumentParser(description='''Indicator to prevent
           computer from sleeping. It depends on the commands xprintidle and
           xdotool being properly installed on your system. If they aren't
           installed already, please install them. Also, the icons are taken from
           caffeine-plus, so if it isn't installed, you will probably see a broken
           icon.''')
       mode = '''The mode can be either indicator (default) or inhibit-process. If
           mode is indicator, then an indicator icon is created. inhibit-process is
           to be called by the indicator. When sleep is inhibited, it runs,
           preventing sleep.'''
       parser.add_argument('--mode', type=str, default='indicator', help=mode)
       return parser.parse_args()
   
   def main():
       args = parse_args()
       if args.mode == 'indicator':
           signal.signal(signal.SIGINT, signal.SIG_DFL)
           GObject.threads_init()
           SleepInhibit()
           Gtk.main()
       elif args.mode == 'inhibit-process':
           inhibit()
       else:
           exit('ERROR: Invalid value for --mode!')
   
   if __name__ == '__main__':
       main()
   

3. 运行脚本。