差别

这里会显示出您选择的修订版和当前版本之间的差别。

--- public:it:linux:ubuntu [2021/07/22 08:59] – oakfire
+++ public:it:linux:ubuntu [2023/07/20 11:41] (当前版本) – [Tips] oakfire
@@ 行 3: / 行 3: @@
 ===== Snap =====
   * [[https://cn.ubuntu.com/blog/what-is-snap-application|What is snap application]]
+===== Audio =====
+  * [[https://linuxhint.com/pulse_audio_sounds_ubuntu/|pulse_audio_sounds_ubuntu]]
 ===== Tips =====
-  * 修改时区 [[https://www.server-world.info/en/note?os=Ubuntu_16.04&p=timezone|timedatectl]]
+  * 搜索软件包：http://packages.ubuntu.com/
+  * Ubuntu18.04 后网络管理：[[https://netplan.io/|netplan]] ''/etc/netplan/'' -> **NetworkManager** [[https://www.cnblogs.com/liuhedong/p/10695969.html|nmcli]]
+  * Ubuntu20.04 更新 openssl : [[https://code.luasoftware.com/tutorials/linux/upgrade-openssl-on-ubuntu-20/|upgrade-openssl-on-ubuntu-20]]<code bash>
+# check version
+openssl version -a
+# backup
+sudo cp -R /usr/lib/ssl /usr/lib/ssl-1.1.1h
+# download latest version https://www.openssl.org/source/
+wget https://www.openssl.org/source/openssl-1.1.1m.tar.gz
+# check
+wget https://www.openssl.org/source/openssl-1.1.1m.tar.gz.sha256
+echo "$(cat openssl-1.1.1m.tar.gz.sha256) openssl-1.1.1m.tar.gz" | sha256sum --check
+# install
+sudo apt update && sudo apt install build-essential -y
+tar -zxvf openssl-1.1.1m.tar.gz
+cd openssl-1.1.1m
+./config
+make
+sudo make install
+sudo mv /usr/bin/openssl /usr/bin/openssl-1.1.1f
+sudo ln -s /usr/local/bin/openssl /usr/bin/openssl
+sudo ldconfig
+# check current version
+openssl version -a
+# fix cert
+cd /usr/local/ssl
+sudo rmdir certs
+sudo ln -s /etc/ssl/certs
+sudo rmdir private/
+sudo ln -s /etc/ssl/private
+sudo mv openssl.cnf openssl.cnf.original
+sudo ln -s /etc/ssl/openssl.cnf
+# check cert
+wget https://www.google.com
+</code>
+  * 修改时区 [[https://www.server-world.info/en/note?os=Ubuntu_16.04&p=timezone|timedatectl]] <code bash>
+# display settings
+timedatectl
+# display timezone list
+timedatectl list-timezones
+# set timezone
+timedatectl set-timezone Asia/Shanghai
+</code>
   * 查看版本:<code bash>lsb_release -a</code>
   * 修改主机名称: <code bash>sudo vim /etc/hostname </code>
@@ 行 22: / 行 67: @@
 sudo apt-get update
 </code>详见 [[https://askubuntu.com/questions/41605/trouble-downloading-packages-list-due-to-a-hash-sum-mismatch-error|Failed to fetch update on Ubuntu 14.04 LTS ]]
+  * 登录之后的欢迎信息来自 ''/etc/update-motd.d/'' 下脚本动态生成的 ''/run/motd.dynamic''
+  * ubuntu 应用列表配置信息目录为 ''/usr/share/application''
+  * 双系统启动选项的配置，ubuntu下修改grub选项 ''sudo vim /etc/default/grub'', 配置<code>
+GRUB_DEFAULT=saved
+GRUB_SAVEDEFAULT=true
+</code>, 然后执行 ''sudo update-grub'', 就可实现启动的默认选项保存为上一次手动选择的结果。
+  * ubuntu 的时间同步用的是 timesyncd , 可用  ''timedatectl'' 来查看时间同步状态
+    * 关闭时间同步：''sudo timedatectl set-ntp no''
+    * 开启时间同步: ''sudo timedatectl set-ntp on''
 ==== 备忘 ====
   * <code bash>
@@ 行 31: / 行 85: @@
 passwd oak
 </code>
+  * 18.04 最小化安装开启远程桌面： <code bash>
+# 安装 vino
+sudo apt-get install vino
+# 配置 vino
+gsettings set org.gnome.Vino enabled true
+gsettings set org.gnome.Vino require-encryption false
+gsettings set org.gnome.Vino prompt-enabled false
+gsettings set org.gnome.Vino view-only false
+gsettings set org.gnome.Vino authentication-methods "['vnc']"
+gsettings set org.gnome.Vino vnc-password $(echo -n "mypassword"|base64)
+# 启动
+/usr/lib/vino/vino-server --display=:0
+</code> 使用 vnc-viewer 客户端来连接
+  * 无人值守安全补丁更新：https://www.cyberciti.biz/faq/set-up-automatic-unattended-updates-for-ubuntu-20-04/ <code bash>
+sudo apt install unattended-upgrades
+sudo dpkg-reconfigure -plow unattended-upgrades  # select yes
+sudo vi /etc/apt/apt.conf.d/50unattended-upgrades
+# Unattended-Upgrade::Automatic-Reboot "true";
+sudo unattended-upgrades --dry-run -d  # test
+sudo unattended-upgrades -d  # manual upgrade.
+</code>