登廬山望石門‧宋鮑照
訪世失隱淪，從山異靈士。
明發振雲冠，升嶠遠棲趾。
高岑隔半天，長崖斷千里。
氛霧承星辰，潭壑洞江汜。
嶄絕類虎牙，巑岏象熊耳。
埋冰或百年，韜樹必千祀。
雞鳴清澗中，猿嘯白雲裏。
瑤波逐穴開，霞石觸峰起。
迴互非一形，參差悉相似。
傾聽鳳管賓，緬望釣龍子。
松桂盈膝前，如何穢城市。
振羽 
騰空之時，音聲分明。發芽 
伏藏之際，難得頃聽。
─── 《樹莓派聲音︰頃聽者》
□ ︰ 為什麼樹莓派自帶之類比一直以來不好？
○ ︰ 因為使用 PWM 之故！
□ ︰ 早有許多 I2S 數位卡，怎麼不改之耶？
○ ︰ 樂求其省又便宜，利於學習和攜帶也。
□ ︰ 不過當今之聲卡既已貴且重矣！！豈至？？
○ ︰ 此乃應用在人，藏富於天下者之思。
＋ ︰ 胡復何有疑焉◎
北斗雖遷仍然指春！古今遺音依舊能解？
念大化川流不息之旨有乎？？！！
Bluetooth audio
In Jessie, we used PulseAudio to provide support for audio over Bluetooth, but integrating this with the ALSA architecture used for other audio sources was clumsy. For Stretch, we are using the bluez-alsa package to make Bluetooth audio work with ALSA itself. PulseAudio is therefore no longer installed by default, and the volume plugin on the taskbar will no longer start and stop PulseAudio. From a user point of view, everything should still work exactly as before – the only change is that if you still wish to use PulseAudio for some other reason, you will need to install it yourself.
※ 註
Bluetooth Audio ALSA Backend
This project is a rebirth of a direct integration between Bluez and ALSA. Since Bluez >= 5, the build-in integration has been removed in favor of 3rd party audio applications. From now on, Bluez acts as a middleware between an audio application, which implements Bluetooth audio profile, and a Bluetooth audio device.
The current status quo is, that in order to stream audio from/to a Bluetooth device, one has to install PulseAudio, or use Bluez < 5. However, Bluez version 4 is considered to be deprecated, so the only reasonable way to achieve this goal is to install PulseAudio.
With this application (later named as BlueALSA), one can achieve the same goal as with PulseAudio, but with less dependencies and more bare-metal-like. BlueALSA registers all known Bluetooth audio profiles in Bluez, so in theory every Bluetooth device (with audio capabilities) can be connected. In order to access the audio stream, one has to connect to the ALSA PCM device called bluealsa. The device is based on the ALSA software PCM plugin.
想古今世代交替之轉無耶！！？？
Better handling of other usernames
The default user account in Raspbian has always been called ‘pi’, and a lot of the desktop applications assume that this is the current user. This has been changed for Stretch, so now applications like Raspberry Pi Configuration no longer assume this to be the case. This means, for example, that the option to automatically log in as the ‘pi’ user will now automatically log in with the name of the current user instead.
One other change is how sudo is handled. By default, the ‘pi’ user is set up with passwordless sudo access. We are no longer assuming this to be the case, so now desktop applications which require sudo access will prompt for the password rather than simply failing to work if a user without passwordless sudo uses them.
』為用；乾坤『 
』借法。
python setup.py install
python
Python 2.7.13 (default, Jan 19 2017, 14:48:08)
[GCC 6.3.0 20170124] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> from guacamole.client import GuacamoleClient
>>> client = GuacamoleClient('127.0.0.1', 4822)
>>> client.handshake(protocol='rdp', hostname='localhost', port=3389)
>>> instruction = client.receive()
>>> instruction
'4.size,1.0,4.1024,3.768;'
>>> instruction = '5.mouse,3.400,3.500;'
>>> client.send(instruction)
>>>
ls
guacamole.war root
pi@raspberrypi:/usr/share/jetty9/webapps 
cd /var/cache/jetty9/data/jetty-0.0.0.0-8080-guacamole.war-_guacamole-any-5680714153949901226.dir/webapp
pi@raspberrypi:/var/cache/jetty9/data/jetty-0.0.0.0-8080-guacamole.war-_guacamole-any-5680714153949901226.dir/webapp 
ls
guacamole.properties user-mapping.xml
(hostname -I) || true
if [ "![_IP" ]; then printf "My IP address is %s\n" "](http://www.freesandal.org/wp-content/ql-cache/quicklatex.com-e606d755f4fcf9ad8fe1e05697062eb2_l3.png "Rendered by QuickLaTeX.com")
_IP"
fi
sudo service guacd restart
exit 0
pi@raspberrypi:~ 
cd /run/systemd/generator.late/
pi@raspberrypi:/run/systemd/generator.late 
pi@raspberrypi:/run/systemd/generator.late ![more guacd.service # Automatically generated by systemd-sysv-generator [Unit] Documentation=man:systemd-sysv-generator(8) SourcePath=/etc/init.d/guacd Description=LSB: Guacamole proxy daemon Before=multi-user.target Before=multi-user.target Before=multi-user.target Before=graphical.target After=network-online.target Wants=network-online.target [Service] Type=forking Restart=no TimeoutSec=5min IgnoreSIGPIPE=no KillMode=process GuessMainPID=no RemainAfterExit=yes SuccessExitStatus=5 6 ExecStart=/etc/init.d/guacd start ExecStop=/etc/init.d/guacd stop pi@raspberrypi:/run/systemd/generator.late](http://www.freesandal.org/wp-content/ql-cache/quicklatex.com-151fc64f82d999a9b7d6b39182290327_l3.png "Rendered by QuickLaTeX.com")
ls
rc-local.service
pi@raspberrypi:/run/systemd/generator/multi-user.target.wants 
more rc-local.service
# This file is part of systemd.
#
# systemd is free software; you can redistribute it and/or modify it
# under the terms of the GNU Lesser General Public License as published by
# the Free Software Foundation; either version 2.1 of the License, or
# (at your option) any later version.
# This unit gets pulled automatically into multi-user.target by
# systemd-rc-local-generator if /etc/rc.local is executable.
[Unit]
Description=/etc/rc.local Compatibility
ConditionFileIsExecutable=/etc/rc.local
After=network.target
[Service]
Type=forking
ExecStart=/etc/rc.local start
TimeoutSec=0
RemainAfterExit=yes
GuessMainPID=no
pi@raspberrypi:/run/systemd/generator/multi-user.target.wants 
systemctl status guacd
● guacd.service - LSB: Guacamole proxy daemon
Loaded: loaded (/etc/init.d/guacd; generated; vendor preset: enabled)
Active: active (running) since Wed 2017-11-08 20:04:57 CST; 1 day 20h ago
Docs: man:systemd-sysv-generator(8)
Process: 420 ExecStart=/etc/init.d/guacd start (code=exited, status=0/SUCCESS)
CGroup: /system.slice/guacd.service
├─ 454 /usr/local/sbin/guacd -p /var/run/guacd.pid
└─2793 /usr/local/sbin/guacd -p /var/run/guacd.pid
Warning: Journal has been rotated since unit was started. Log output is incomple
pi@raspberrypi:~ $
network”, “
portmap”, “
systemctl status jetty9
more /etc/init.d/jetty9
remote_fs 
local_fs 
network
named![more jetty9.service # Automatically generated by systemd-sysv-generator [Unit] Documentation=man:systemd-sysv-generator(8) SourcePath=/etc/init.d/jetty9 Description=LSB: Start Jetty Before=multi-user.target Before=multi-user.target Before=multi-user.target Before=graphical.target After=remote-fs.target After=network-online.target After=nss-lookup.target Wants=network-online.target [Service] Type=forking Restart=no TimeoutSec=5min IgnoreSIGPIPE=no KillMode=process GuessMainPID=no RemainAfterExit=yes SuccessExitStatus=5 6 ExecStart=/etc/init.d/jetty9 start ExecStop=/etc/init.d/jetty9 stop pi@raspberrypi:/run/systemd/generator.late](http://www.freesandal.org/wp-content/ql-cache/quicklatex.com-ebe65b33ed33f59299b0245feea6c0b0_l3.png "Rendered by QuickLaTeX.com")