# Linux Basic Notes ## Linux Boot System ### Grub #### Grub Configuration - `/etc/default/grub`配置文件, 用于一些基本的修改项, 如默认启动项, Grub 界面等待时长, Grub 主题 etc. More details in `info -f grub -n 'Simple configuration'` ```bash # Default Startup OS GRUB_DEFAULT=0 # Default Timeout GRUB_TIMEOUT=5 # https://github.com/vinceliuice/grub2-themes GRUB_THEME="/boot/grub/themes/Tela/theme.txt" ``` - `/etc/grub.d/*`生成`/boot/grub/grub.cfg`的执行脚本(`update-grub`命令), 可以更细致地修改启动项, 如各个启动项的名称、顺序等. #### Grub Repair ##### Windows Repair - easyBCD for non-efi loader - with efi loader, run command: ```bash # root commander bcdedit /set "{bootmgr}" path \EFI\ubuntu\grubx64.efi ``` ##### Ubuntu Live Repair ```bash sudo add-apt add-apt-repository ppa:yannubuntu/boot-repair sudo apt update sudo apt install boot-repair boot-repair ``` ### 重装 Linux - 自动挂载项 /etc/fstab etc/rc.local - 自定义脚本-新建目录(加入环境变量) - 自定义别名 ~/.bashrc ## SSH 命令 ### Key ```bash ssh-keygen -t rsa ssh-add ~/.ssh/id_rsa ``` ### SSHD - config file in `/etc/ssh/sshd_config` ```bash sudo systemctl reload sshd sudo service restart sshd ``` ### SSH Config File `~/.ssh/config`: - Host 别名 - HostName 主机名(ip) `ssh user@ip` - Port 可忽略 - User 登录用户名 `ssh user@ip` - PreferredAuthentications publicKey - IdentityFile 密钥文件完整路径 `ssh -i file` ```bash Host github.com HostName github.com PreferredAuthentications publicKey IdentityFile ~/.ssh/id_rsa Host cs.github.com HostName github.com PreferredAuthentications publicKey IdentityFile ~/.ssh/cs Host cloud HostName xx.org User root IdentityFile ~/.ssh/dsl_private_key Host bwg HostName 23.106.150.152 User root Port 29692 ``` ```bash git clone git@github.com:user/repo git clone git@cs.github.com:user/repo ``` ```bash ssh -qTfnN -D 7070 bwg google-chrome socks5 127.0.0.1 7070 ``` ### 密钥文件 - 登录远程主机：ssh -i sabertaz root@119.29.140.60 - 文件传输：sftp -i sabertaz root@119.29.140.60 - 登录数据库：mysql -h 10.66.135.125 -P 3306 -u root -p ### 远程传输文件 ```bash rsync -ax -e 'ssh -c blowfish' /root/start_dir root@x.x.x.x:/root/dest_dir ``` ```bash sshpass -p "$DEPLOY_PASSWORD" \ scp -o StrictHostKeyChecking=no \ -P $DEPLOY_PORT \ -r ./build $DEPLOY_USER@$DEPLOY_ADDR:/var/www/html ``` ## 命令优先级包含路径命令 ./vmtools.pl \>别名命令 \>bash 内部命令 \>\$PATH 包含目录内的命令 /bin /sbin ## Linux 文件架构 ```bash man hier ``` 通过源码包安装的软件，可以通过 ./configure --prefix=/opt/ - `/usr/src`: Kernel source code. - `/usr/share/applications`: Desktop shortcuts. - `/usr/share/fonts/opentype`: Open Type Fonts (OTF). - `/usr/share/fonts/truetype`: True Type Fonts (TTF). - `/etc/nginx`: Nginx. ## Ubuntu ### Ubuntu Locale Settings ```bash export LANG=en_US xdg-user-dirs-gtk-update export LANG=zh_CN ``` - /var/lib/locales/supported.d/local ```bash sudo locale-gen zh_CN.GBK sudo locale-gen zh_CN.GB18030 sudo dpkg-reconfigure locales ``` ### Ubuntu Themes #### Icon Themes Nightly build for Numix Circle icon: ```bash sudo add-apt-repository ppa:numix/ppa sudo apt update sudo apt install numix-icon-theme-circle ``` #### GTK Themes GTK/GNOME themes located in `/usr/share/themes/` or `~/.themes/`: ```bash # Vimix Cursors Installation git clone https://github.com/vinceliuice/Vimix-cursors sudo ./Vimix-cursors/install.sh # WhiteSur GNOME theme Installation git clone https://github.com/vinceliuice/WhiteSur-gtk-theme sudo ./WhiteSur-gtk-theme/install.sh -t all -i ubuntu # Tweak for Firefox sudo ./WhiteSur-gtk-theme/tweaks.sh -f # Tweak for Snap Apps sudo ./WhiteSur-gtk-theme/tweaks.sh -s # Tweak for GDM sudo ./WhiteSur-gtk-theme/tweaks.sh -g -i ubuntu # Tweak Help Docs sudo ./WhiteSur-gtk-theme/tweaks.sh -h ``` Repair for not detected HDMI problem: ```bash sudo dpkg-reconfigure gdm3 sudo apt install --reinstall gdm3 lightdm ubuntu-desktop ``` #### GNOME Shell Extension - Install GNOME shell extension for browser. - Install local binding app: `sudo apt install chrome-gnome-shell`. - Visit `extensions.gnome.org` to install extensions. ### Ubuntu Fonts ```bash mkdir -p ~/.local/share/fonts/ cp -fr code-fonts ~/.local/share/fonts/ fc-cache -f -v fc-list fc-list : family | sort | uniq ``` ## Arch Linux ### Setup Arch Linux Configuration ```bash less /usr/share/aif/docs/official_installation_guide_en pacman -S lynx arch-wiki-docs arch-wiki-lite lynx /usr/share/doc/arch-wiki/html/index.html ``` ```bash systemctl enable dhcpcd reboot pacman -S --needed base-devel git wget jshon expac yajl zsh vim ``` - makepkg ```bash curl -L -O https://aur.archlinux.org/cgit/aur.git/snapshot/package_name.tar.gz cd package_name less PKGBUILD less package_name.install makepkg -si # -s sync deps # -i install # -r rm deps # -c clean up ``` ### Pacman - /etc/pacman.conf - /etc/pacman.d/mirrorlist ### AUR - [yaourt](https://archlinux.fr/yaourt-en) ```bash # packages' list wget https://aur.archlinux.org/packages.gz ``` ## Basic Commands ### ls - -lh(long human) - -ld(long directory) - -i inode(ID 号) --color==auto 权限(user/group/other) 引用计数 user group 文件大小文件修改时间文件名 ### cd - -上次目录 - ..上级目录 ### pwd print working directory ### rm - –r delete directory - –f delete forcedly - -i 显示确认信息 ### cp - -r copy directory - -p copy property - -d copy link - -a --all(-pdr) - -i 显示确认信息 ### mv 无需参数(改名+移动) - -i 显示确认信息 ### ln link: create `.bak/.hard` (硬链接) and `.soft` (软链接：创建链接时填写绝对路径). - A hard link always points a filename to data on a storage device. - A soft link always points a filename to another filename, which then points to information on a storage device. ```bash ln [源文件] [New Hard Link File] ln -s [源文件] [New Soft Link File] ``` ### history - -c 清除历史命令 - -w (~/.bash_history) 保存历史命令 /etc/profile 中修改 HISTSIZE !n/!!/!字符串重复执行第 n 条/上一条/指定开头的历史命令 ```bash # repeat history command !number ``` ### ctrl-r press ctrl-r 提示符改变，显示我们正在执行反向增量搜索。搜索过程是”反向的”，因为我们按照从”现在”到过去某个时间段的顺序来搜寻。下一步，我们开始输入要查找的文本搜索返回我们需要的结果。 (enter to execute, ctrl-j to copy) ### History Shortcuts | command | function | | :------ | :----------------------------------- | | Ctrl-p | 移动到上一个历史条目 | | Ctrl-n | 移动到下一个历史条目 | | Alt-< | 移动到历史列表开头 | | Alt-> | 移动到历史列表结尾 | | Ctrl-r | 反向增量搜索 | | Alt-p | 反向搜索，非增量搜索 | | Alt-n | 向前搜索，非增量 | | Ctrl-o | 执行历史列表中的当前项，并移到下一个 | ## Find and Search Commands ### locate 结合 updatedb 命令(该命令一般自动 1 天/次) ### type indicate how a command name is interpreted ### apropos display a list of appropriate commands ### whereis and whatis ### which ### find `find [搜索路径] [可选参数] [文件名](可加"")`: - -name - -iname 不区分大小写 - -user `user_name` 按照所有者搜索 - -nouser 搜索没有所有者的文件 - -atime(文件访问时间)/-ctime(改变文件属性)/-mtime(改变文件内容) -10(十天内)/10(十天当天)/+10(十天前) - -size(文件大小) -25k(小于 25k)/25M(25M)/+25G(大于 25G) - -inum `inode_number` - -a / -o 逻辑与/逻辑或(左右两端搜索条件) - -exec/-ok `system_command_list {} \;对搜索结果执行操作 ### Grep `grep` `[可选参数] '字符串' 文件名`: - `-I`: 不区分大小写 - `-v`: 排除指定字符串 - `-r`: recursive on directory - `-l`: only print matched filename - `--exclude` Find `FunctionalComponent` in files and open them all: ```bash grep -lr FunctionalComponent src --exclude=\*.md | xargs code ``` ## CPU and Process Commands ### uptime Average load information ### ps Report a snapshot of current processes ```bash ps aux ``` ### top top/htop: - Display tasks - Average load - Process status - CPU usage atop: - Memory usage - Disk I/O usage - Network usage ### vmstat Outputs a snapshot of system resource usage: - CPU usage - Context switch times - Interrupt times (/proc/interrupts) - Running and exclusive process status - Memory usage - Swap space - Disk I/O usage ### pidstat Process and Thread: - CPU usage - Context switch times - Interrupt times (/proc/interrupts) ```bash pidstat 1 ``` ### mpstat - CPU usage - Software interrupt times (/proc/interrupts) ```bash mpstat -P ALL 1 ``` ### lscpu Show `/proc/cpuinfo`. ### jobs list active jobs ### bg place a job in the background ### fg place a job in the foreground ### kill send a signal to a process ### killall kill processes by name ### shutdown shutdown or reboot the system ### pstree outputs a process list arranged in a tree-like pattern ### xload and tload draws a graph showing system load over time ### screen ```bash screen -S screenName screen -ls screen -r ``` - Ctrl+d // detach window - Ctrl+k // kill window ## CLI Input Output Commands ### cat concatenate files ### sort sort lines of text ### uniq report or omit repeated lines ### wc print newline, word, and byte counts for each file ### Head and Tail output the first/last part of a file ```bash head -n 5 filename tail -f filename ``` ### Tee read from standard input and write to standard output and files ```bash [me@linuxBox ~]$ ls /usr/bin | tee ls.txt | grep zip bunzip2 bzip2 .... ``` ### nl number lines ### fold wrap each line to a specified length ### fmt a simple text formatter ### pr prepare text for printing ### printf format and print data ## Helper and Documentation Commands ### man - -f 显示操作等级 - -k 包含匹配 - -1/2/.../9 显示命令不同操作等级的帮助 1. Commands (Programs) Those commands that can be executed by the user from within a shell. 2. System calls Those functions which must be performed by the kernel. 3. Library calls Most of the libc functions. 4. Special files (devices) Files found in /dev. 5. File formats and conventions The format for /etc/passwd and other human-readable files. 6. Games 7. Conventions and miscellaneous Overviews of various topics, conventions and protocols, character set standards, and miscellaneous other things. 8. System management commands Commands like mount(8), many of which only root can execute. ### help shell 内部命令显示 shell 内部命令帮助，如 cd 命令(shell 内部命令) ### info 显示大型帮助文档 - enter 进入 u 返回 p 上一节 n 下一节 q 退出 ### System Info ```bash sudo add-apt-repository ppa:dawidd0811/neofetch sudo apt-get update sudo apt-get install neofetch ``` ```bash sudo apt-get install screenfetch ``` ## Compress and Extract Commands ### Zip - zip -r(目录) 压缩文件源文件/源目录 - unzip 源文件 -d 指定路径 ### Gz - gzip 源文件 - gzip –c 源文件 > 压缩文件 - gzip -r 源目录将源目录下所有子文件分别单独压缩 - gzip –d(解压缩) 文件 - gunzip 压缩文件 ### Bz2 不可压缩目录 - bzip2 –k(保留源文件) 源文件 - bzip2 –d(解压缩) –k(保留压缩文件) 压缩文件 - bunzip2 –k(保留压缩文件) 压缩文件 ### Tar tar.gz/.tar.bz2: tar [可选参数] 压缩文件(可指定压缩路径) [-c 解压缩路径]源文件/源目录 - -z 将.tar 压缩为.tar.gz -j 将.tar 压缩为.tar.bz2 - -c 打包 -x 解打包 - -t 查看压缩文件 - -v 显示过程 - -f 指定压缩文件名 - -C 指定解压缩路径 - -zcvf/-zxvf/-ztcf -jcvf/-jxvf/-jtvf ### 7z ```bash 7z x manager.7z -r -o /home/xx 7z a -t7z -r manager.7z /home/manager/* ``` - a: add - x: extract - -r: recursive - -o: specific path - -t: type ## User and Group Commands - w/who 查看用户详细信息 - last 显示所有用户登陆信息(/var/log/wtmp) - lastlog 显示所有用户最后一次登陆时间(/var/log/lastlog) ### 组操作 #### 创建组 groupadd test #### 修改组 groupmod -n test2 test -g #### 删除组 groupdel test2 #### 查看组 - groups someUser - cat /etc/group ```bash cat /etc/passwd | awk -F [:] ‘{print $4}’ \ |sort|uniq | getent group |awk -F [:] ‘{print $1}’ ``` ### 用户操作 #### 增加用户 ```bash useradd [options] LOGIN ``` Options: - -b, --base-dir BASE_DIR 设置基本路径作为用户的登录目录 - -c, --comment COMMENT 对用户的注释 - -d, --home-dir HOME_DIR 设置用户的登录目录 - -D, --defaults 改变设置 - -e, --expiredate EXPIRE_DATE 设置用户的有效期 - -f, --inactive INACTIVE 用户过期后，让密码无效 - -g, --gid GROUP 使用户只属于某个组 - -G, --groups GROUPS 使用户加入某个组(附设组) - -h, --help 帮助 - -k, --skel SKEL_DIR 指定其他的 skel 目录 - -K, --key KEY=VALUE 覆盖 /etc/login.defs 配置文件 - -m, --create-home 自动创建登录目录 - -l, 不把用户加入到 lastlog 文件中 - -M, 不自动创建登录目录 - -r, 建立系统账号 - -o, --non-unique 允许用户拥有相同的 UID - -p, --password PASSWORD 为新用户使用加密密码 - -s, --shell SHELL 登录时候的 shell - -u, --uid UID 为新用户指定一个 UID - -Z, --selinux-user SEUSER use a specific SEUSER for the SELinux user mapping ```bash useradd -s bash -m testUser passwd testUser # modify `/etc/passwd`, then add to `/etc/sudoers` ``` `adduser` is a perl script which uses `useradd` binary in back-end, `adduser` is more user friendly and interactive. #### 修改用户 usermod -d /home/test -G test2 test - -l 新用户名旧用户名修改用户名 - -g 新用户组目标用户改变用户所属组 gpasswd -a test test2 将用户 test 加入到 test2 组(附设组) gpasswd -d test test2 将用户 test 从 test2 组中移出 ```bash usermod -aG sudo ``` #### 删除用户 userdel test -r 同时删除用户登录目录(/home/xxx) #### 查看用户 w/who 查看当前登录的所有用户 whoami 查看当前登录用户名 finger apacheUser 查看单个用户信息 #### 限制用户 - passwd -l 用户名锁定用户 - passwd -u 用户名解锁用户 - passwd -d 用户名清除用户密码 ## Privilege Management Commands ### Common Privilege Management - chown 用户名：组名文件名 - chgrp 组名文件名 - umask 存储位置 ——/etc/profile - 文件默认权限 = 文件默认最大权限 rw-(666) 减去 umask 值(如----w--w-)(022) - 目录默认权限 = 目录默认最大权限 rwx(777) 减去 umask 值 - `id ` ### ACL Privilege Management - 查看分区 ACL 权限是否开启 dumpe2fs -h 设备分区名 - 临时开启分区 ACL 权限 mount -o remount,acl 设备分区名 - 永久开启分区 ACL 权限 /etc/fstab - setfacl -m (d:默认权限) u/g:用户名/组名:权限(rwx) 文件名 - getfacl 文件名——查看文件 ACL 权限 ### Sudo Privilege Management /etc/sudoers.tmp ### SetUID and SetGID 可执行程序/目录+普通用户临时获得 root 权限（rws）: - chmod 0xxx 取消双权限 - chmod 2xxx 设置 SetGID 权限 - chmod 4xxx 设置 SetUID 权限 - chmod 6xxx 设置双权限 ## Disk IO Commands 主分区(primary)与延伸分区(extended) 延伸分区可以继续划分成逻辑分区(logical) ### 挂载命令 mount [-t 文件系统][-o 特殊选项] 设备文件名挂载点(挂载目录/media /misc /mnt) - 无参数显示当前挂载设备 - -a 依据/etc/fstab 文件配置,自动挂载 umount 设备文件名/挂载点 fdisk –l ### 修复命令 ```bash sudo debugfs /dev/sda9 > debugfs: lsdel ``` ### 分区命令 #### fdisk 分区表类型 MBR n p e l 新主逻辑扩展分区 w 激活 #### parted 分区表类型 MBR/GPT - mklabel 选择分区表类型 - print 打印分区信息 - mkpart 新建分区 - rm 删除分区 - unit 选择单位 - quit 结束分区 ### Zero Copy - `read` + `write`: 4 context switch, 4 data copy (2 DMA, 2 CPU). - `mmap` + `write`: 4 context switch, 3 data copy (2 DMA, 1 CPU). - `sendfile`: 2 context switch, 3 data copy (2 DMA, 1 CPU). - scatter and gather `sendfile`: 2 context switch, 2 data copy (1 DMA, 1 SG-DMA). - 传输大文件 (无法命中内核 PageCache) 使用 `异步 I/O` + `直接 I/O`, 传输小文件使用 Zero Copy. ```nginx location /video/ { sendfile on; aio on; directio 1024m; } ``` ## Device Management Commands ### Host System Info Commands ```bash #!/bin/bash # Simple print cpu topology # numactl --hardware # ls /sys/devices/system/node/node0 # lscpu function get_nr_processor() { grep '^processor' /proc/cpuinfo | wc -l } function get_nr_socket() { grep 'physical id' /proc/cpuinfo | awk -F: '{ print $2 | "sort -un"}' | wc -l } function get_nr_siblings() { grep 'siblings' /proc/cpuinfo | awk -F: '{ print $2 | "sort -un"}' } function get_nr_cores_of_socket() { grep 'cpu cores' /proc/cpuinfo | awk -F: '{ print $2 | "sort -un"}' } echo '===== CPU Topology Table =====' echo echo '+--------------+---------+-----------+' echo '| Processor ID | Core ID | Socket ID |' echo '+--------------+---------+-----------+' while read line; do if [ -z "$line" ]; then printf '| %-12s | %-7s | %-9s |\n' $p_id $c_id $s_id echo '+--------------+---------+-----------+' continue fi if echo "$line" | grep -q "^processor"; then p_id=`echo "$line" | awk -F: '{print $2}' | tr -d ' '` fi if echo "$line" | grep -q "^core id"; then c_id=`echo "$line" | awk -F: '{print $2}' | tr -d ' '` fi if echo "$line" | grep -q "^physical id"; then s_id=`echo "$line" | awk -F: '{print $2}' | tr -d ' '` fi done < /proc/cpuinfo echo awk -F: '{ if ($1 ~ /processor/) { gsub(/ /,"",$2); p_id=$2; } else if ($1 ~ /physical id/){ gsub(/ /,"",$2); s_id=$2; arr[s_id]=arr[s_id] " " p_id } } END{ for (i in arr) printf "Socket %s:%s\n", i, arr[i]; }' /proc/cpuinfo echo echo '===== CPU Info Summary =====' echo nr_processor=`get_nr_processor` echo "Logical processors: $nr_processor" nr_socket=`get_nr_socket` echo "Physical socket: $nr_socket" nr_siblings=`get_nr_siblings` echo "Siblings in one socket: $nr_siblings" nr_cores=`get_nr_cores_of_socket` echo "Cores in one socket: $nr_cores" let nr_cores*=nr_socket echo "Cores in total: $nr_cores" if [ "$nr_cores" = "$nr_processor" ]; then echo "Hyper-Threading: off" else echo "Hyper-Threading: on" fi echo echo '===== END =====' ``` ### Screen Monitor Commands #### xrandr ```bash xrandr -s 1920x1800 # set resolution ``` #### Monitor Info ```bash sudo apt-get install read-edid sudo get-edid | parse-edid ``` ### Touch Pad Synoptics ```bash synclient TouchpadOff=0 ``` ## Package Manager Commands ### RPM Commands 安装和卸载时同时存在依赖性(包依赖、库依赖) rpm 查询: - -q 包名查询已安装的包 //必备参数 - -a 查询所有已安装的包 - -i 查询软件信息 - -l list - -f 查询系统文件属于哪个软件包 - -R 查询软件包的依赖性 - -p 查询未安装包 //普适参数 rpm 校验(查看 Cracker 信息): - -V 校验已安装包相应信息不是.号便是被修改项可用于找回丢失的系统命令 ### YUM Commands 源配置文件:/etc/yum.repos.d ```bash cd /etc/yum.repos.d mv CentOS-Base.repo CentOS-Base.repo.bk wget http://mirrors.163.com/.help/CentOS7-Base-163.repo yum makecache ``` - yum list - yum search 'keyword' - yum -y(自动回答 yes) install 包名 - yum -y update 包名 - yum -y remove 包名 - yum grouplist - yum groupinstall 软件组名 - yum groupremove 软件组名 ### Source Code Installation 指定位置: - /usr/local/软件名/ - /usr/local/src/软件名/ (如上述脚本出错，执行 make clean） ```bash make install ``` e.g apache /var/www/html/index.html /usr/local/apache/htdocs/index.html ### Applications Management Commands - desktop shortcut: `/usr/share/applications` - startup apps: `gnome-session-properties` or `gnome-tweaks` ### Default Management Commands `update-alternatives`: maintain symbolic links determining default commands. ```bash sudo update-alternatives --get-selections ``` ```bash sudo update-alternatives --install /usr/bin/x-terminal-emulator \ x-terminal-emulator /opt/Hyper/hyper 50 ``` ```bash sudo update-alternatives --config x-terminal-emulator ``` ### APT Key Commands ```bash # Add key sudo apt-add-repository ppa:user/repo sudo apt update # Delete key via last 8 bits sudo apt-key list sudo apt-key del 73C62A18 sudo apt update ``` ## Network Commands ### wget - 下载全站资料 - -P 表示下载到哪个目录 - -r 表示递归下载 - -np 表示不下载旁站连接. - -k 表示将下载的网页里的链接修改为本地链接. - -p 获得所有显示网页所需的元素 ```bash wget -r -p -np -k -P ~/tmp/ http://java-er.com ``` ### Certificate Bot [CertBot](https://github.com/certbot/certbot) for SSL certificates. ### GFW - [Hosts](https://github.com/racaljk/hosts) - [RSS](https://github.com/breakwa11/shadowsocks-rss) - [ChinaDNS](https://github.com/shadowsocks/ChinaDNS-Python) - [ProxyChains](https://github.com/rofl0r/proxychains-ng) - [OpenVPN](https://github.com/OpenVPN/openvpn) - [VPNGate](https://github.com/waylau/vpngate-mirrors) - [DockerVPN](https://github.com/hwdsl2/docker-ipsec-vpn-server) ```bash yum install python-setuptools && easy_install pip pip install shadowsocks echo "nohup sslocal -c /etc/shadowsocks.json /dev/null 2>&1 &" /etc/rc.local nohup ssserver -c /etc/shadowsocks.json -d start /dev/null 2>&1 & ``` ### NetWork Management Commands | 用途 | net-tool(被淘汰) | iproute2 | | :------------- | :--------------- | :--------------- | | 地址和链路配置 | ifconfig | ip addr, ip link | | 路由表 | route | ip route | | 邻居 | arp | ip neigh | | VLAN | vconfig | ip link | | 隧道 | iptunnel | ip tunnel | | 组播 | ipmaddr | ip maddr | | 统计 | netstat | ss | ```bash ip link show ip address show ip route show # add commands to /etc/init.d/local.sh rm -fr /etc/udev/rules.d/70-persistent-net.rules # start up network adapter ip link set eth0 up # add/delete static ip ip address add 192.168.1.1/24 dev eth0 ip address del 192.168.1.1/24 dev eth0 # add/delete static route ip route add 192.168.1.0/24 dev eth0 ip route del 192.168.1.0/24 dev eth0 ip route add default via 192.168.0.196 # watch packets watch -n 1 "ifconfig eth0" watch -n 1 "ifconfig eth1" watch -n 1 "ifconfig eth2" ``` ### ufw ```bash ufw status ufw enable ufw allow ssh ufw allow http ufw allow https ``` ### arp `arp -a`显示地址解析协议 (IP 地址—网卡地址): - 网际互联层：IP 协议(网际)、IGMP 协议(互联网组管理)、ICMP 协议(互联网控制报文) - 传输层：TCP 协议(传输控制)、UDP 协议(用户数据报) ### netstat `netstat -an`查看本机启用的端口: - (-a 查看所有连接和监听端口 -n 显示 IP 地址和端口号) - -t tcp 协议端口 - -u udp 协议端口 - -l 监听状态服务 ### nslookup `nslookup domain_name`查看 DNS 解析器: /etc/network/interfaces 主机名: - /etc/hostname - /etc/sysconfig/network - /etc/resolv.conf ### ping `ping -c ip/domain`探测网络状况 ### telnet `telnet [ip/domain] [端口]`远程管理与端口探测命令 ### Trace Route - `traceroute [-n IP] domain`路由跟踪命令 - `traceroute -n -I -T -p`路由扫描 ### Net Filter Framework nftables 命令行工具：nft ### fping `fping -a -u -g -f [target]`批量扫描主机地址 ### hping `hping -p -S -a`可伪造 IP 地址 ### mtr 路由扫描 ### nmap 批量主机服务扫描: - -P ICMP - -sS TCP SYN - -sT TCP connect() - -sU UDP ### ncat 批量主机服务扫描: - -w 设置超时时间 - -v 显示命令执行过程 - -z 一个输入输出模式 - -u UDP 协议 ## Shell Execution Commands exec 1>>output.log exec 2>>error.log ### Systemctl ```bash systemctl enable local ``` in `/etc/init.d/local` ```bash #!/bin/bash ### BEGIN INIT INFO # Provides: local # Required-Start: $all # Required-Stop: # Default-Start: 3 4 5 # Default-Stop: # Short-Description: Personal start script sslocal -c shadowsocks.json -d start ``` 内存控制 ```bash sysctl vm [-options] CONFIG swapoff ``` ### Crontab Commands - `/etc/crontab` - [Crontab Quick Tutorial](https://linuxtools-rst.readthedocs.io/zh_CN/latest/tool/crontab.html) - [Crontab Generator](https://crontab.guru) ```bash crontab -l(list) crontab -e(establish) ``` - m,n —— 分隔多个时间 - m-n —— 表示时间范围 - /n —— 表示每隔 n 时间 - 天数与星期设置之间是 “或”关系 - /var/spool/cron/user_name/ - /var/log/con - /etc/cron.\*ly 时间表 - /etc/anacrontab: 异步时间表 ### Background Job Commands - jobs —— 所有作业 - atq —— 延时作业队列 - at -M(不使用邮件发送运行结果) -f filename deltaTime - atrm 作业号/名 - bg/fg 作业号/名 - nohup 脚本 & —— 脱离控制台并后台运行脚本 19 ~ -20 （-20 优先级最高） - nice -n number 作业号/名 - renice number -p PID ### Startup Job Commands - /etc/rc.local —— 系统开机任务 - /etc/profile/ /etc/bash.bashrc —— bash 启动任务/远程登陆任务 - /etc/bash.bashrc —— SSH 连接任务 ### Parallel Execution 命令间插入符 - command1;command2 顺序执行，相当于 C 语言中语句结束符 - command1&&command2 命令同时执行(当 1 正确时)或同时不执行(当 1 出错时) - command1 || command2 只执行一个命令(正确命令) - command1 | command2 前一正确命令的输出结果作为后一命令的输入结果 > e.g ls && echo yes >> .log || echo no >> .log ## C/C++ Binary Commands ### ldd ```bash ldd ./lib.sio ``` ### nm ```bash nm -Ca ./lib.so ``` ## Plot Commands chart.gp ```bash #!/usr/bin/env gnuplot set term wxt enhanced set xtics set view set multiplot set size set origin fit plot 'data.dat' using 1:2, 'data.dat' using 1:3 ``` ```bash #!/usr/bin/gnuplot -c set terminal png enhanced set output ARG1.".png" set style data linespoints show timestamp set title ARG1 set xlabel "time (seconds)" set ylabel "Segments (cwnd, ssthresh)" plot ARG1 using 1:7 title "snd_cwnd", \ ARG1 using 1:($8>=2147483647 ? 0 : $8) title "snd_ssthresh" ``` ## Other Commands ### Time ```bash date ``` change ntp (Network Time Protocol) time ```bash sudo apt-get install ntpdate sudo iptables -A OUTPUT -p udp --dport 123 -j ACCEPT sudo iptables -A INPUT -p udp --sport 123 -j ACCEPT sudo ntpdate time.windows.com sudo hwclock --localtime --systohc ``` use local time (not UTC time) ```bash sudo timedatectl set-local-rtc 1 ``` ## Shell Scripts ### Shell Warnings - = 左右无空格 - () [] 内部最好有空格 - 数值运算用 (()) 或 \$(()) ### 文件重定向 - `>` 文件名/输出设备名覆盖标准输出重定向 - `>>` 文件名/输出设备名追加标准输出重定向 - 2>(右端无空格)文件名/输出设备名覆盖错误输出重定向 - 2>>(右端无空格)文件名/输出设备名追加错误输出重定向 - `>/>> 文件 2>&1 &>/&>>文件` 覆盖/追加正确输出与错误输出同时重定向 - `=2147483647 ? 0 : \$8) title "snd_ssthresh" EOF ``` ### 变量 #### 基本变量 - `=` : 左右两端不可有空格 - `' '`: 完全标准字符串 - `" "`: 格式化字符串 - 调用变量值：\$变量名 - set/unset——设置/取消变量 #### built-in 变量 - `$*`/`$@`: `argv[1], ..., argv[n]` - `$0/$1/../$n`: `argv[0], ..., argv[n]` - `$#`: argc - `$?`: exit code of last command ```bash if [ "$?" -ne "0" ];then echo "sorry, command execution failed!" fi ``` 每次 shift 命令执行的时候，变量 $2 的值会移动到变量 $1 中，变量 $3 的值会移动到变量 $2 中. 变量 \$# 的值也会相应的减 1 ```bash #!/bin/bash # posit-param2: script to display all arguments count=1 while [[ $# -gt 0 ]]; do echo "Argument $count = $1" count=$((count + 1)) shift done ``` ```bash usage () { echo "$PROGNAME: usage: $PROGNAME [-f file | -i]" return } # process command line options interactive= filename= while [[ -n $1 ]]; do case $1 in -f | --file) shift filename=$1 ;; -i | --interactive) interactive=1 ;; -h | --help) usage exit ;; *) usage >&2 exit 1 ;; esac shift done ``` #### 环境变量 - /etc/profile.d/\*.sh - ~/.bash_profile - ~/.bashrc - /etc/profile - /etc/bash.bashrc - /etc/issue——shell 登录信息 - PS1 环境变量——shell 头行打印信息 - PATH 环境变量 ##### Environment Command - env——查看环境变量 - export 变量名=变量值——设置环境变量 - printenv ### 数值运算 #### declare 命令 ### Bash Expansions - `$(())` or `$[]`: arithmetic expansion 一般地, 将数值运算用 `(())` `[[]]` 或 `$(())` 括起, 可以确保变量不会被识别为 string ```bash read x read y echo $((x + y)) echo $((a < b ? a : b)) if ((a > b)) then echo "a > b" fi if [[ a -gt b ]] then echo "a > b" fi if [ "$a" -gt "$b" ] then echo "a > b" fi ``` - `[[ xxx ]]`: condition - `(( xxx ))`: arithmetic condition | operator | function | | :-------------------- | :------------------------------------------------ | | ! EXPRESSION | The EXPRESSION is false | | -n STRING | The length of STRING is greater than zero | | -z STRING | The length of STRING is zero (ie it is empty) | | STRING1 == STRING2 | STRING1 is equal to STRING2 | | STRING1 != STRING2 | STRING1 is not equal to STRING2 | | STRING1 > STRING2 | STRING1 sorts after STRING2 | | STRING1 < STRING2 | STRING1 sorts before STRING2 | | INTEGER1 -eq INTEGER2 | INTEGER1 is numerically equal to INTEGER2 | | INTEGER1 -gt INTEGER2 | INTEGER1 is numerically greater than INTEGER2 | | INTEGER1 -lt INTEGER2 | INTEGER1 is numerically less than INTEGER2 | | -d FILE | FILE exists and is a directory | | -e FILE | FILE exists | | -r FILE | FILE exists and the read permission is granted | | -s FILE | FILE exists and it's size is greater than zero | | -w FILE | FILE exists and the write permission is granted | | -x FILE | FILE exists and the execute permission is granted | | `AND -a &&` | | | `OR -o \|\|` | | | `NOT ! !` | | - {}: group regexp ```bash echo a{A{1,2},B{3,4}}b aA1b aA2b aB3b aB4b ``` - `${}`: string expansion - `${parameter:-word}`: 若 parameter 没有设置（例如，不存在）或者为空，展开结果是 word 的值。若 parameter 不为空，则展开结果是 parameter 的值 - `${parameter:+word}`: 若 parameter 没有设置或为空，展开结果为空。若 parameter 不为空，展开结果是 word 的值会替换掉 parameter 的值 - `${parameter:=word}`: 若 parameter 没有设置或为空，展开结果是 word 的值。另外，word 的值会赋值给 parameter。若 parameter 不为空，展开结果是 parameter 的值 - `${parameter:?word}`: 若 parameter 没有设置或为空，这种展开导致脚本带有错误退出，并且 word 的内容会发送到标准错误。若 parameter 不为空，展开结果是 parameter 的值 - `${!prefix*}` `${!prefix@}`: 这种展开会返回以 prefix 开头的已有变量名 - `${#parameter}`: 展开成由 parameter 所包含的字符串的长度 - `${parameter:offset}` `${parameter:offset:length}`: 提取一部分字符 - `${parameter,,}` 把 parameter 的值全部展开成小写字母 - `${parameter,}` 仅仅把 parameter 的第一个字符展开成小写字母 - `${parameter^^}` 把 parameter 的值全部转换成大写字母 - `${parameter^}` 仅仅把 parameter 的第一个字符转换成大写字母 - `${parameter#pattern}` `${parameter##pattern}`, `${parameter%pattern}` `${parameter%%pattern}`: 从 parameter 所包含的字符串中清除开头/末尾一部分文本 - `${parameter/pattern/string}`, `${parameter//pattern/string}`, `${parameter/#pattern/string}`, `${parameter/%pattern/string}`: replace ```bash foo=file.txt.zip echo ${foo#*.} txt.zip echo ${foo##*.} zip foo=file.txt.zip echo ${foo%.*} file.txt echo ${foo%%.*} file ``` ```bash foo=JPG.JPG echo ${foo/JPG/jpg} jpg.JPG echo ${foo//JPG/jpg} jpg.jpg echo ${foo/#JPG/jpg} jpg.JPG echo ${foo/%JPG/jpg} JPG.jpg ``` - \$(): command result - "": allow expansions string - '': disallow expansions string ### 流程控制语句 #### if 语句 ```bash if [[ 条件判断式 ]] ; then 程序 fi if [[ 条件判断式 ]] then 程序 else 程序 fi if [[ 条件判断式1 ]] then 程序1 elif [[ 条件判断式2 ]] then 程序2 …… else 程序n fi ``` #### case 语句 ```bash case $变量名 in “值1”) 程序 ;; “值2”) 程序 ;; *) 程序 ;; esac ``` | case pattern | function | | :------------- | :------------------------------------ | | `a)` | word equals "a" | | `[[:alpha:]])` | word is a single alphabetic character | | `???)` | word is exactly three characters long | | `\*.txt)` | word ends with the characters “.txt” | | `*)` | any value of word | ```bash #!/bin/bash # case-menu: a menu driven system information program clear echo " Please Select: 1. Display System Information 2. Display Disk Space 3. Display Home Space Utilization 0. Quit " read -p "Enter selection [0-3] > " case $REPLY in 0) echo "Program terminated." exit ;; 1) echo "Hostname: $HOSTNAME" uptime ;; 2) df -h ;; 3) if [[ $(id -u) -eq 0 ]]; then echo "Home Space Utilization (All Users)" du -sh /home/* else echo "Home Space Utilization ($USER)" du -sh $HOME fi ;; *) echo "Invalid entry" >&2 exit 1 ;; esac ``` or case pattern ```bash #!/bin/bash # case-menu: a menu driven system information program clear echo " Please Select: A. Display System Information B. Display Disk Space C. Display Home Space Utilization Q. Quit " read -p "Enter selection [A, B, C or Q] > " case $REPLY in q|Q) echo "Program terminated." exit ;; a|A) echo "Hostname: $HOSTNAME" uptime ;; b|B) df -h ;; c|C) if [[ $(id -u) -eq 0 ]]; then echo "Home Space Utilization (All Users)" du -sh /home/* else echo "Home Space Utilization ($USER)" du -sh $HOME fi ;; *) echo "Invalid entry" >&2 exit 1 ;; esac ``` fall through case pattern (`;;&`) ```bash #!/bin/bash # case4-2: test a character read -n 1 -p "Type a character > " echo case $REPLY in [[:upper:]]) echo "'$REPLY' is upper case." ;;& [[:lower:]]) echo "'$REPLY' is lower case." ;;& [[:alpha:]]) echo "'$REPLY' is alphabetic." ;;& [[:digit:]]) echo "'$REPLY' is a digit." ;;& [[:graph:]]) echo "'$REPLY' is a visible character." ;;& [[:punct:]]) echo "'$REPLY' is a punctuation symbol." ;;& [[:space:]]) echo "'$REPLY' is a whitespace character." ;;& [[:xdigit:]]) echo "'$REPLY' is a hexadecimal digit." ;;& esac ``` #### for 语句 ```bash for 变量 in 值1 值2 值3 …… 值n do 程序 done $(seq 1 50) # 1 2 ... 50 {1..50} # 1 2 ... 50 {0..10..2} # 0 2 4 6 8 10 for (( 初始值;循环控制条件;变量变化 )); do 程序 done ``` #### while 语句与 until 语句 ```bash while [[ 条件判断式 ]] do 程序 done until [[ 条件判断式 ]] do 程序 done ``` ```bash (( expression1 )) while (( expression2 )); do commands (( expression3 )) done ``` ```bash #!/bin/bash # while-menu: a menu driven system information program DELAY=3 # Number of seconds to display results while [[ $REPLY != 0 ]]; do clear cat <<- _EOF_ Please Select: 1. Display System Information 2. Display Disk Space 3. Display Home Space Utilization 0. Quit _EOF_ read -p "Enter selection [0-3] > " if [[ $REPLY =~ ^[0-3]$ ]]; then if [[ $REPLY == 1 ]]; then echo "Hostname: $HOSTNAME" uptime sleep $DELAY fi if [[ $REPLY == 2 ]]; then df -h sleep $DELAY fi if [[ $REPLY == 3 ]]; then if [[ $(id -u) -eq 0 ]]; then echo "Home Space Utilization (All Users)" du -sh /home/* else echo "Home Space Utilization ($USER)" du -sh $HOME fi sleep $DELAY fi else echo "Invalid entry." sleep $DELAY fi done echo "Program terminated." ``` ```bash #!/bin/bash # while-read: read lines from a file while read dist version release; do printf "Dist: %s\tVersion: %s\tReleased: %s\n" \ $dist \ $version \ $release done < dist.txt ``` #### do while statement ```bash while : ; do actions [[ current_time <= $cutoff ]] || break done ``` ### Bash Array - [Array Reference](http://billie66.github.io/TLCL/book/chap36.html) ### Bash Function - 函数局部变量 local + 变量名 - 函数参数 : \$ + #/？/@/n - 引用函数库文件 —— source sh 文件名 / . sh 文件名可修改~/.bashrc 文件 ### Bash IO ```bash #!/bin/bash # read-validate: validate input invalid_input () { echo "Invalid input '$REPLY'" >&2 exit 1 } read -p "Enter a single item > " # input is empty (invalid) [[ -z $REPLY ]] && invalid_input # input is multiple items (invalid) (( $(echo $REPLY | wc -w) > 1 )) && invalid_input # is input a valid filename? if [[ $REPLY =~ ^[-[:alnum:]\._]+$ ]]; then echo "'$REPLY' is a valid filename." if [[ -e $REPLY ]]; then echo "And file '$REPLY' exists." else echo "However, file '$REPLY' does not exist." fi # is input a floating point number? if [[ $REPLY =~ ^-?[[:digit:]]*\.[[:digit:]]+$ ]]; then echo "'$REPLY' is a floating point number." else echo "'$REPLY' is not a floating point number." fi # is input an integer? if [[ $REPLY =~ ^-?[[:digit:]]+$ ]]; then echo "'$REPLY' is an integer." else echo "'$REPLY' is not an integer." fi else echo "The string '$REPLY' is not a valid filename." fi ``` ```bash #!/bin/bash # read-menu: a menu driven system information program clear echo " Please Select: 1. Display System Information 2. Display Disk Space 3. Display Home Space Utilization 0. Quit " read -p "Enter selection [0-3] > " if [[ $REPLY =~ ^[0-3]$ ]]; then if [[ $REPLY == 0 ]]; then echo "Program terminated." exit fi if [[ $REPLY == 1 ]]; then echo "Hostname: $HOSTNAME" uptime exit fi if [[ $REPLY == 2 ]]; then df -h exit fi if [[ $REPLY == 3 ]]; then if [[ $(id -u) -eq 0 ]]; then echo "Home Space Utilization (All Users)" du -sh /home/* else echo "Home Space Utilization ($USER)" du -sh $HOME fi exit fi else echo "Invalid entry." >&2 exit 1 fi ``` ```bash # interactive mode if [[ -n $interactive ]]; then while true; do read -p "Enter name of output file: " filename if [[ -e $filename ]]; then read -p "'$filename' exists. Overwrite? [y/n/q] > " case $REPLY in Y|y) break ;; Q|q) echo "Program terminated." exit ;; *) continue ;; esac elif [[ -z $filename ]]; then continue else break fi done fi ``` ### 信号 - man 7 signal —— 传递信号给进程 - CTRL + C —— SIGINT - CTRL + Z —— SIGSTP - kill/killall —— SIGINT - trap SIG\*/EXIT —— 捕捉信号(后 + 忽略信号/默认处理信号/自定义处理信号) - trap – SIG\*/EXIT —— 移除信号 ### Bash Debugging `-x` option ```bash #!/bin/bash -x # trouble: script to demonstrate common errors number=1 if [ $number = 1 ]; then echo "Number is equal to 1." else echo "Number is not equal to 1." fi ``` ```bash #!/bin/bash # trouble: script to demonstrate common errors number=1 echo "number=$number" # DEBUG set -x # Turn on tracing if [ $number = 1 ]; then echo "Number is equal to 1." else echo "Number is not equal to 1." fi set +x # Turn off tracing ``` ### Shell Script Best Practices - [Google Shell Style Guide](https://google.github.io/styleguide/shellguide.html) - 指定默认解释器`cat /etc/shells` - 设置`bash strict mode` - 条件判断使用`[[ ]]` - 使用变量时用双引号把变量包起来 `cp -r "$src_dir" "$dest_dir"` - 使用`$()`获取表达式的值 - 使用`${arr[@]}`进行列表循环 ```bash #!/usr/bin/env bash # 设置命令回显 set -x # 遇到未声明的变量则报错停止 set -u # 遇到执行错误则停止 set -e # 管道命令其中一步失败则中止 set -o pipefail ``` ### Interactive Shell Script Tips #### Check Root Validation ```bash if (( $EUID != 0 )); then echo "Please run as root!" exit fi ``` ```bash # run as root directly sudo chown root sudo chmod +s ``` #### Bash help option ```bash #!/bin/sh if [[ ${#@} -ne 0 ]] && [[ "${@#"--help"}" = "" ]]; then printf -- '...help...\n'; exit 0; fi; ``` #### Bash Silent Option ```bash #!/bin/sh if [[ ${#@} -ne 0 ]] && [[ "${@#"--silent"}" = "" ]]; then stty -echo; fi; # ... # before point of intended output: stty +echo && printf -- 'intended output\n'; # silence it again till end of script stty -echo; # ... stty +echo; exit 0; ``` #### Check Command Validation ```bash #!/bin/sh _=$(command -v docker); if [[ "$?" != "0" ]]; then printf -- 'You don\'t seem to have Docker installed.\n'; printf -- 'Get it: https://www.docker.com/community-edition\n'; printf -- 'Exiting with code 127...\n'; exit 127; fi; ``` ##### Get Absolute Path ```bash #!/bin/sh CUR_DIR="$(dirname $0);" printf -- 'moving application to /opt/app.jar'; mv "${CUR_DIR}/application.jar" /opt/app.jar; ``` #### Bash error handle ```bash #!/bin/sh error_handle() { stty echo; } if [[ ${#@} -ne 0 ]] && [[ "${@#"--silent"}" = "" ]]; then stty -echo; trap error_handle INT; trap error_handle TERM; trap error_handle KILL; trap error_handle EXIT; fi; # ... ``` #### Bash loading progress ```bash #!/bin/sh printf -- 'Performing asynchronous action..'; ./trigger-action; DONE=0; while [ $DONE -eq 0 ]; do ./async-checker; if [ "$?" = "0" ]; then DONE=1; fi; printf -- '.'; sleep 1; done; printf -- ' DONE!\n'; ``` ### Zsh ```bash # Install zsh and powerline sudo apt install zsh powerline powerline-status # Install oh-my-zsh sh -c "$(wget -O- https://raw.githubusercontent.com/ohmyzsh/ohmyzsh/master/tools/install.sh)" # Install zsh themes git clone --depth=1 https://github.com/romkatv/powerlevel10k.git ${ZSH_CUSTOM:-$HOME/.oh-my-zsh/custom}/themes/powerlevel10k git clone --depth=1 https://github.com/sabertazimi/dragon-zsh-theme.git ${ZSH_CUSTOM:-$HOME/.oh-my-zsh/custom}/themes/dragon # Install zsh plugins git clone https://github.com/zsh-users/zsh-autosuggestions ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-autosuggestions git clone https://github.com/zsh-users/zsh-syntax-highlighting.git ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-syntax-highlighting plugins=( command-not-found fzf git git-prompt github history lighthouse man node npm nvm pm2 vi-mode yarn ) ``` ## Terminal ### Terminal Basis - 电传打字机 (TeleTypeWriter, TTY) 是物理设备, 最初是为电报设计, 后来被连接到计算机上, 发送输入和获取输出. - 电传打字机 (TTY) 现在被运行在内核中的模块所模拟, 被称为终端模拟器 (Terminal Emulator). - 伪终端 (Pseudo Terminal, PTY) 是运行在用户区的终端模拟程序. - Shell 由 Terminal fork 出来, 是 Terminal 的子进程. Terminal 处理键盘事件, 负责字符的显示. Shell 负责解释执行用户输入的字符, 返回操作系统底层响应. - 可以使用 `stty` 命令对 TTY 设备进行配置. - 远程终端 `ssh` 也是一种伪终端 PTY: - Local: PTY Master is Terminal, PTY Slave is `bash` and `ssh client`. - Remote: PTY Master is `ssh server`, PTY Slave is `bash`. ### Default Terminal `update-alternatives`: maintain symbolic links determining default commands. ```bash sudo update-alternatives --get-selections ``` ```bash sudo update-alternatives --install /usr/bin/x-terminal-emulator \ x-terminal-emulator /opt/Hyper/hyper 50 ``` ```bash sudo update-alternatives --config x-terminal-emulator ``` ### Tmux #### Basic Tmux Commands ```bash tmux ls tmux new -s sessionID tmux a -t sessionID # attach tmux show -g >> current.tmux.conf # export configuration ``` #### Basic Hotkeys ```bash ? # 快捷键帮助列表 ``` ##### Session management ```bash :new # 创建新的 Session，其中 : 是进入 Tmux 命令行的快捷键 s list sessions $ rename the current session d detach from the current session ``` ##### Tmux Windows Hotkeys ```bash c create a new window , rename the current window w list windows % split horizontally " split vertically n change to the next window p change to the previous window 0 to 9 select windows 0 through 9 ``` ##### Tmux Panes Hotkeys ```bash % create a horizontal pane " create a vertical pane # 切换 Pane 布局 h move to the left pane. * j move to the pane below * l move to the right pane * k move to the pane above * q show pane numbers o toggle between panes } swap with next pane { swap with previous pane ! break the pane out of the window x kill the current pane t # 显示一个时钟 ``` ##### Tmux Scroll - `C-a + [` to into scroll mode, `q` to quit scroll mode - copy mode can scroll too - `set -g mouse on` for enabling mouse scrolling #### Tmux Configuration ```bash # C-b is not acceptable -- Vim uses it set-option -g prefix C-a bind-key C-a last-window # Start numbering at 1 set -g base-index 1 # Allows for faster key repetition set -s escape-time 0 # Set status bar set -g status-bg black set -g status-fg white set -g status-left "" set -g status-right "#[fg=green]#H" # Enable scroll mouse set -g mouse on # Rather than constraining window size to the maximum size of any client # connected to the *session*, constrain window size to the maximum size of any # client connected to *that window*. Much more reasonable. setw -g aggressive-resize on # Allows us to use C-a a to send commands to a TMUX session inside # another TMUX session bind-key a send-prefix # Reload configuration bind r source-file ~/.tmux.conf \; display-message "Config reloaded" # Escape to enter copy mode, v to selection, y to yank, p to paste bind Escape copy-mode bind-key -T copy-mode-vi 'v' send -X begin-selection bind-key -T copy-mode-vi 'y' send -X copy-selection-and-cancel # bind-key -t vi-copy v begin-selection # bind-key -t vi-copy y copy-pipe "reattach-to-user-namespace pbcopy" unbind p bind p pasteb setw -g mode-keys vi # Vi # Highlight active window set-window-option -g window-status-current-bg red ``` ## Perf Tools ### Top Command ```bash top ``` ### dmesg ```bash dmesg | tail ``` ### iostat ```bash iostat -xz 1 ``` ### free ```bash free -m ``` ### sar ```bash `sar -n DEV 1` ``` ```bash `sar -n TCP,ETCP 1` ``` ### perf [Perf Examples](http://www.brendangregg.com/perf.html) ```bash perf list # events perf stat perf stat -e perf record -e -a perf report ``` ## Linux Tools ### FFmpeg ```bash # https://www.yanxurui.cc/posts/tool/2017-10-07-use-ffmpeg-to-edit-video ffmpeg -global_options -input_1_options -i input_1 -input_2_options -i input_2 \ -output_1_options output_1 ... ``` #### FFmpeg Probe ```bash ffprobe input.mp4 ffmpeg -hide_banner -i input.mkv ``` #### FFmpeg Transform - `MP4`: `H264`Video + `ACC`Audio - `WebM`: `VP8`Video + `Vorbis`Audio - `OGG`: `Theora`Video + `Vorbis`Audio ```bash # code decoder information ffmpeg -codecs ``` ```bash # mkv to mp4 ffmpeg -i input.mkv -codec copy output.mp4 ``` ```bash # compress ffmpeg -i input.mkv -c copy -c:v libx264 -vf scale=-2:720 output.mkv ``` ```bash # make mkv with video and subtitle ffmpeg -i input.avi -i input.srt \ -map 0:0 -map 0:1 -map 1:0 -c:v libx264 -c:a aac -c:s srt output.mkv ``` ```bash # flac to mp3 ffmpeg -i "Michael Jackson - Billie Jean.flac" \ -ab 320k "Michael Jackson - Billie Jean.mp3" ffmpeg -i music_flac.flac \ -acodec libmp3lame \ -ar 44100 \ -ab 320k \ -ac 2 music_flac_mp3.mp3 # - acodec: Audio Coder Decoder 音频编码解码器 # - libmp3lame: MP3 解码器 # - ar: audio rate 音频采样率, 默认用原音频的采样率 # - ab: audio bit rate 音频比特率, 默认 128K # - ac: audio channels 音频声道, 默认采用源音频的声道数 ``` ```bash # mp4 to avi ffmpeg -i video.mp4 \ -s 1920x1080 \ -pix_fmt yuv420p \ -vcodec libx264 \ -preset medium \ -profile:v high \ -level:v 4.1 \ -crf 23 \ -r 30 \ -acodec aac \ -ar 44100 \ -ac 2 \ -b:a 128k video_avi.avi # - s: 缩放视频新尺寸 (size) # - pix_fmt：pixel format, 设置视频颜色空间 # - vcodec: Video Coder Decoder, 视频编码解码器 # - preset: 编码器预设 # - profile:v: 编码器配置, 与压缩比有关. 实时通讯-baseline, 流媒体-main, 超清视频-high # - level:v: 对编码器设置的具体规范和限制, 权衡压缩比和画质 # - crf: 设置码率控制模式, constant rate factor恒定速率因子模式, 范围 0~51, 数值越小, 画质越高 # - r:设置视频帧率 # - b:a: 音频比特率, 大多数网站限制音频比特率 128k, 129k ``` #### FFmpeg Cutting ```bash # audio only ffmpeg -i cut.mp4 -vn output.mp3 ffmpeg -i video.mp4 -vn -acodec copy video_noVideo.m4a # video only ffmpeg -i video.mp4 -vcodec copy -an video_silent.mp4 ``` ```bash # from to cutting ffmpeg -i music.mp3 -ss 00:00:30 -to 00:02:00 -acodec copy music_cutout.mp3 ffmpeg -i in.mp4 -ss 00:01:00 -to 00:01:10 -c copy out.mp4 ffmpeg -ss 00:01:00 -i in.mp4 -to 00:01:10 -c copy -copyts out.mp4 # 30s duration cutting ffmpeg -ss 00:02:00.0 -i input.mkv -t 30 -c copy output.mkv ffmpeg -i input.mkv -ss 00:02:00.0 -t 30 -c copy output.mkv ffmpeg -ss 00:01:30.0 -i input.mkv -ss 00:00:30.0 -t 30 output.mkv ``` #### FFmpeg Mixing ```bash # replace audio ffmpeg -i input.mkv -i input.mp3 -map 0:v -map 1:a -c copy -shortest output.mp4 # merge audio and video ffmpeg -i video_noVideo.m4a -i video_silent.mp4 -c copy video_merge.mp4 ffmpeg -i "concat:01.mp4|02.mp4|03.mp4" -c copy out.mp4 ffmpeg -i input.mkv -i output.aac \ -filter_complex "[0:a][1:a]amerge=inputs=2[a]" -map 0:v -map "[a]" \ -c:v copy -c:a aac -ac 2 -shortest output.mp4 ``` #### FFmpeg Screenshot ```bash # -vf -> -filter:v ffmpeg -ss 00:30:14.435 -i input.mkv -vframes 1 out.png ffmpeg -i input.mkv -vf fps=1/60 -strftime 1 out_%Y%m%d%H%M%S.jpg ``` #### FFmpeg Gif ```bash ffmpeg -i video.mp4 -ss 7.5 -to 8.5 -s 640x320 -r 15 video_gif.gif palette="/tmp/palette.png" filters="fps=10,scale=-1:144:flags=lanczos" ffmpeg -ss 30 -t 5 -i input.mp4 -vf "$filters,palettegen" -y $palette ffmpeg -ss 30 -t 5 -i input.mp4 -i $palette \ -filter_complex "$filters [x]; [x][1:v] paletteuse" -y output.gif ``` #### FFmpeg Subtitle ```bash ffmpeg -i input.mkv -vf subtitles=input.srt output.mp4 ffmpeg -i input.mkv -vf ass=input.ass output.mp4 ``` #### FFmpeg Watermark ```bash ffmpeg -i input.mkv -i input.png \ -filter_complex "overlay=W-w-5:5" -c copy -c:v libx264 output.mkv ``` #### FFmpeg Desktop Recording ```bash # windows ffmpeg -f gdigrab -i desktop rec.mp4 # linux sudo ffmpeg -f fbdev -framerate 10 -i /dev/fb0 rec.mp4 ``` #### FFmpeg Live Streaming ```bash ffmpeg -re i rec.mp4 按照网站要求编码 -f flv "你的 RTMP 地址/你的直播码" ``` ### Nginx - `/etc/nginx/sites-available`: sites config ```bash nginx -t # check config syntax ``` #### Nginx Basic Configuration 泛域名路径分离: `xxx.test.dev` -> `/usr/local/html/xxx` ```bash server { listen 80; server_name ~^([\w-]+)\.test\.dev$; root /usr/local/html/$1; } ``` ```bash server { # SSL configuration # # listen 443 ssl default_server; # listen [::]:443 ssl default_server; # root /var/www/html/; # Add index.php to the list if you are using PHP index index.html index.htm index.nginx-debian.html; server_name example.tld www.example.tld; # Cache static assets location ~* \.(?:jpg|jpeg|gif|png|ico|svg)$ { expires 7d; add_header Cache-Control "public"; } location ^~ /assets/ { gzip_static on; expires 12h; add_header Cache-Control "public"; } # Cache css and js bundle location ~* \.(?:css|js)$ { add_header Cache-Control "no-cache, public, must-revalidate, proxy-revalidate"; } location / { include /etc/nginx/mime.types; try_files $uri $uri/ /index.html; # try_files $uri $uri/ =404; # proxy_http_version 1.1; # proxy_cache_bypass $http_upgrade; # proxy_set_header Upgrade $http_upgrade; # proxy_set_header Connection 'upgrade'; # proxy_set_header Host $host; # proxy_set_header X-Real-IP $remote_addr; # proxy_set_header X-Forwarded-For $proxy_add_x_forwarded_for; # proxy_set_header X-Forwarded-Proto $scheme; # proxy_pass http://localhost:3000; } } ``` ### Namespaces and Cgroup #### Namespaces ```bash # PID Namespace unshare --fork --pid --mount-proc /bin/bash ps -aux # Mount Namespace unshare --fork --mount /bin/bash mkdir /tmp/mnt mount -t tmpfs -o size=1m tmpfs /tmp/mnt df -h |grep mnt # User Namespace PS1='\u@container#' unshare --user -r /bin/bash # UTS Namespace (isolated hostname) unshare --fork --uts /bin/bash hostname -b container # IPC Namespace unshare --fork --ipc /bin/bash ipcmk -Q ipcs -q # Net Namespace unshare --fork --net /bin/bash ip addr netstat -ntlp ``` #### Cgroup Cgroup (Linux Control Group): limit process group resources usage, including CPU, Memory, Disk I/O, Network Bandwidth etc. - Resource usage limit. - Priority. - Resource record. - Process Control. List cgroup ```bash mount -t cgroup ls -l /sys/fs/cgroup/ ``` Create cgroup ```bash mkdir /sys/fs/cgroup/cpu/loop ls -l /sys/fs/cgroup/cpu/loop cat /sys/fs/cgroup/cpu/loop/cpu.cfs_period_us # 100000us cat /sys/fs/cgroup/cpu/loop/cpu.cfs_quota_us # -1 (no limit) ``` Resource control via cgroup ```bash # limit cpu usage to 50% echo 50000 >/sys/fs/cgroup/cpu/loop/cpu.cfs_quota_us # add pid to `loop` cgroup echo 21497 >/sys/fs/cgroup/cpu/loop/tasks ``` ### Docker #### Docker Installation ```bash sudo apt-get update sudo apt-get install \ apt-transport-https \ ca-certificates \ curl \ gnupg \ lsb-release curl -fsSL https://download.docker.com/linux/ubuntu/gpg | sudo apt-key add - sudo add-apt-repository \ "deb [arch=amd64] https://download.docker.com/linux/ubuntu $(lsb_release -cs) stable" sudo apt update sudo apt install docker-ce docker-ce-cli containerd.io ``` ```bash curl -fsSL https://get.docker.com -o get-docker.sh sudo DRY_RUN=1 sh get-docker.sh ``` ```bash sudo systemctl status docker sudo usermod -aG docker $USER ``` #### Docker Uninstallation ```bash docker container stop $(docker container ls -aq) docker system prune -a --volumes sudo apt purge docker-ce docker-ce-cli containerd.io sudo apt autoremove sudo rm -rf /var/lib/docker sudo rm -rf /var/lib/containerd ``` #### Docker Basic Usage ##### Build Docker Image ```bash docker build . -t image-name # use Dockerfile at the root of the repository docker build -t image-name ``` ##### Run Docker Image ```bash # docker run -dp : [docker-image] docker run -d -p 80:80 --name app-name docker/getting-started docker run -d -p 80:80/tcp -p 80:80/udp --name app-name docker/getting-started ```