# linux * [Linux Releases](#linux-releases) * [Install](#install) * [Download](#download) * [Debian](#debian) * [Ubuntu](#ubuntu) * [Mirrors](#mirrors) * [Bash](#bash) * [tmux](#tmux) * [Init](#init) * [login & non-login shells](#login--non-login-shells) * [supervisord](#supervisord) * [Exit code](#exit-code) * [Syslog Message Severities](#syslog-message-severities) * [Signals](#signals) * [kill](#kill) * [top](#top) * [Glances - A top/htop alternative - Python](#glances---a-tophtop-alternative---python) * [User & Permission](#user--permission) * [add user to group](#add-user-to-group) * [rename](#rename) * [password](#password) * [sudoers](#sudoers) * [chown](#chown) * [Package Management](#package-management) * [Redhat](#redhat) * [Ubuntu](#ubuntu-1) * [Debian](#debian-1) * [experimental](#experimental) * [dpkg](#dpkg) * [apt](#apt) * [ssh server](#ssh-server) * [Grub](#grub) * [grub-customizer](#grub-customizer) * [boot .iso](#boot-iso) * [boot repair](#boot-repair) * [ubuntu](#ubuntu-2) * [Serial](#serial) * [client](#client) * [Benchmark](#benchmark) * [mosh](#mosh) * [sshd](#sshd) * [ssh redirect](#ssh-redirect) * [web](#web) * [wget](#wget) * [curl](#curl) * [files](#files) * [find](#find) * [grep](#grep) * [compress/uncompress](#compressuncompress) * [rsync](#rsync) * [history without line numbers](#history-without-line-numbers) * [hostname](#hostname) * [font](#font) * [SELinux](#selinux) * [Dropbox](#dropbox) * [link account](#link-account) * [Ubuntu snap](#ubuntu-snap) * [Proxy](#proxy) * [JAVA\_HOME](#java_home) * [I18N & I10N](#i18n--i10n) * [Chrome](#chrome) * [AD](#ad) * [cache diagnostics](#cache-diagnostics) * [WOL](#wol) * [Tools - Online](#tools---online) * [CPU](#cpu) * [check\_cpu\_core\_mapping](#check_cpu_core_mapping) * [USB Persistence](#usb-persistence) * [kali](#kali) * [ssh](#ssh) * [tools](#tools) * [Video](#video) * [OpenCL](#opencl) * [zFCP](#zfcp) * [Diagram](#diagram) * [diskless](#diskless) ## Linux Releases [RHEL](https://access.redhat.com/articles/3078) | [Ubuntu](https://en.wikipedia.org/wiki/Ubuntu_version_history#Table_of_versions) | [Debian](https://en.wikipedia.org/wiki/Debian_version_history#Release_table) ``` 6.0 Squeeze 2.6.32 -> Security until February 2016 7 Wheezy 3.2 -> Security until May 2018 8 Jessie 3.16 -> Security until April/May 2020 9 Stretch 4.9 -> Security until June 2022 10 Buster 4.19 -> Security until June 2024 11 Bullseye 5.10 -> Security until June 2026 12 Bookworm 6.1 -> Security until June 2028 ``` ## Install from existing: ## Download ### Debian ### Ubuntu ( Mirror only , need proxy, local DNS not working ) Debug: Console 4 or /var/log/syslog ## Mirrors * * apt install netselect-apt && netselect-apt -c china --nonfree mv /etc/apt/sources.list /etc/apt/sources.list.ori && mv sources.list /etc/apt/ ## Bash ``` url=https://raw.githubusercontent.com/fzinfz/scripts/master/init.sh # alias & functions source /dev/stdin <<< "$(curl -sS $url)" set -x debug -T If set, any traps on DEBUG and RETURN are inherited -o functrace/errtrace shopt [-pqsu] [-o] [optname …] -s: Enable (set) each optname. -u: Disable (unset) each optname. shopt -s expand_aliases # when the shell is not interactive alias foo='...' 0: stdin; 1: stdout; 2: stderr # File descriptor 2>&1 >/dev/null &>/dev/null ssh-add 2>/dev/null ``` ### tmux ``` ctrl+b x -> kill pane # /usr/share/doc/tmux/examples/screen-keys.conf cat /usr/share/doc/tmux/examples/screen-keys.conf | grep '\bbind \w' ``` ## Init | Level | Desc | | ----- | ---------------------------------------------------------------------- | | 0 | Halt the system. | | 1 | Single-user mode (for special administration). | | 2 | Local Multiuser with Networking but without network service (like NFS) | | 3 | Full Multiuser with Networking | | 4 | Not Used | | 5 | Full Multiuser with Networking and X Windows(GUI) | | 6 | Reboot. | ``` ls -R -l /etc/rc* ls -l /usr/lib/systemd # check `systemd` page for more ls -l /usr/share/upstart # last release 2014; 3 years ago ls -l /etc/init.d # SysV init cat /etc/modules-load.d/* apt install systemd-sysv # make link: /sbin/init -> /lib/systemd/systemd ``` ### login & non-login shells ``` login shells： /etc/profile ~/.bash_profile(?-> ~/.bashrc), ~/.bash_login, and ~/.profile exit: ~/.bash_logout non-login shells： ~/.bashrc # echo $0 : `shopt login_shell` \| $- -bash : login_shell on | himBHs # bash # echo $0 : `shopt login_shell` \| $- bash : login_shell off | himBHs # bash -c 'echo $0 : `shopt login_shell` \| $-' bash : login_shell off | hBc ``` ### supervisord ## Exit code ``` 1 Catchall for general errors 2 Misuse of shell builtins 126 Command invoked cannot execute 127 "command not found" illegal_command Possible problem with $PATH or a typo 128+n Fatal error signal "n" kill -9 $PPID of script $? returns 137 (128 + 9) 130 Script terminated by Control-C ``` ## Syslog Message Severities ``` 0 Emergency: system is unusable 1 Alert: action must be taken immediately 2 Critical: critical conditions 3 Error: error conditions 4 Warning: warning conditions 5 Notice: normal but significant condition 6 Informational: informational messages 7 Debug: debug-level messages ``` ## Signals ``` kill -l 1) SIGHUP 2) SIGINT 3) SIGQUIT 4) SIGILL 5) SIGTRAP 6) SIGABRT 7) SIGBUS 8) SIGFPE 9) SIGKILL ... 64) SIGRTMAX ``` ## kill ``` pkill -KILL -u {username} ``` ## top ``` * 1 - Single Cpu Off (thus multiple cpus) * c - Command line Off (name, not cmdline) * i - Idle tasks On (show all tasks) j - Str align right Off (not right justify) V - Forest view On (show as branches) f - sort/hide columns (`*') could be overridden through the command-line. ``` ### Glances - A top/htop alternative - Python ``` pip install glances[action,browser,cloud,cpuinfo,chart,docker,export,folders,gpu,ip,raid,snmp,web,wifi] ``` ## User & Permission ### add user to group ``` sudo adduser foobar www-data sudo usermod -a -G ftp tony ``` ### rename ``` pkill -9 -u ubuntu usermod --login fzinfz --move-home --home /home/fzinfz ubuntu sed -i 's/ubuntu/fzinfz/' /etc/sudoers ``` ### password ``` echo user:pwd | chpasswd ``` ### sudoers ``` sudo visudo root ALL=(ALL) ALL # {terminals}=({users}) {commands} %supergroup ALL=(ALL) NOPASSWD:ALL ``` ### chown ``` chown -h myuser:mygroup mysymbolic ``` ## Package Management ### Redhat Free RHEL： ``` subscription-manager register subscription-manager attach --auto subscription-manager repos --enable rhel-7-server-optional-rpms subscription-manager repos --enable rhel-7-server-extras-rpms yum install epel-release rm -f /var/run/yum.pid && yum remove PackageKit yum-config-manager --disable c7-media yum --nogpgcheck localinstall xx.rpm ### EPEL http://elrepo.org/tiki/tiki-index.php rpm --import https://www.elrepo.org/RPM-GPG-KEY-elrepo.org rpm -Uvh http://www.elrepo.org/elrepo-release-7.0-3.el7.elrepo.noarch.rpm yum install yum-plugin-fastestmirror yum --enablerepo=elrepo-kernel install kernel-ml ``` ### Ubuntu Main - Canonical-supported free and open-source software.\ Universe - Community-maintained free and open-source software.\ Restricted - Proprietary drivers for devices.\ Multiverse - Software restricted by copyright or legal issues. ``` # https://mirror.tuna.tsinghua.edu.cn/help/ubuntu/ deb https://mirrors.tuna.tsinghua.edu.cn/ubuntu/ xenial main restricted universe multiverse ``` ### Debian → experimental\ → unstable(Sid) → testing → stable\ Unstable - repository where new & untested packages are introduced.\ Testing - repository with packages from unstable, if no bug are found within 10 days. `main` consists of DFSG-compliant packages, which do not rely on software outside this area to operate. These are the only packages considered part of the Debian distribution.\ `contrib` packages contain DFSG-compliant software, but have dependencies not in main (possibly packaged for Debian in non-free).\ `non-free` contains software that does not comply with the DFSG. ``` deb http://mirror.sjtu.edu.cn/debian/ bullseye main contrib non-free ``` #### experimental ``` deb http://mirror.sjtu.edu.cn/debian/ experimental main contrib non-free apt install -t experimental linux-image-amd64 # latest kernel ``` ### dpkg ``` dpkg --get-selections # list installed ``` To install .deb manually, visit `linux/kernel` page. ### apt ``` apt-get install linux-base -t jessie-backports apt-cache search linux-image | grep linux-image-4 apt install linux-image-4.10.0-9-generic linux-image-extra-4.10.0-9-generic apt show linux-image-extra-4.10* apt-get install --only-upgrade docker-engine apt policy docker-ce | head -n 20 apt-get autoclean apt list --installed rm -r /var/lib/apt/lists/* ``` ``` echo 'Acquire::http::Proxy "http://192.168.88.25:7890"; ' > /etc/apt/apt.conf.d/proxy ``` ### ssh server ``` deb http://.../debian/ buster main contrib non-free apt install openssh-server # not "openssl" journalctl -u ssh # fix： ssh-rsa not in PubkeyAcceptedAlgorithms PubkeyAcceptedAlgorithms +ssh-rsa ``` ## Grub ``` grub2-mkconfig -o /boot/grub2/grub.cfg awk -F\' '/menuentry / {print $2}' /boot/grub/grub.cfg grub2-set-default 'CentOS Linux (4.9.0-rc8-amd64) 7 (Core)' grub2-editenv list ``` fix: ### grub-customizer ``` sudo add-apt-repository ppa:danielrichter2007/grub-customizer sudo apt-get update sudo apt-get install grub-customizer ``` ### boot .iso ``` apt install grub-imageboot mkdir /boot/images && cd /boot/images wget https://boot.netboot.xyz/ipxe/netboot.xyz.iso update-grub2 ``` ## boot repair apt install linux-image-\* # if vmlinuz & initrd.img missing ### ubuntu ``` sudo add-apt-repository ppa:yannubuntu/boot-repair sudo apt-get update sudo apt-get install -y boot-repair && boot-repair ``` ## Serial ``` GRUB_CMDLINE_LINUX="console=tty0 console=ttyS0,115200n8" ``` ### client ``` screen /dev/ttyUSB0 115200 picocom -b 115200 /dev/ttyUSB0 ``` ## Benchmark ``` sysbench --test=cpu --cpu-max-prime=20000 --num-threads=32 run wget http://www.numberworld.org/y-cruncher/y-cruncher%20v0.7.9.9510-static.tar.xz tar -xf y-cruncher*.tar.xz ``` ## mosh ``` apt install mosh -y ss -lntup | grep mosh # 60000:61000/udp | **after** client connected ``` ## sshd mobaxterm login failed: No supported authentication methods ``` PubkeyAcceptedAlgorithms +ssh-rsa # sshd_config # journalctl -u ssh ``` ## ssh redirect ``` ssh -L 9000:public.com:80 # visit local:9000 -> public.com:80 ssh -L 0.0.0.0:54321:127.0.0.1:54321 remote -p 22 ssh -R 9000:localhost:3000 # visit remote:9000 -> local:3000, "GatewayPorts yes" in sshd_config -nNT -L ... # port forwarding only, no shell ``` ## web ### wget ``` wget -O diff_name.zip http://... ``` ### curl ``` curl -O http://... curl -o diff_name.zip http:// curl -sSL $1 -f, --fail Fail silently (no output at all) on HTTP errors (H) -s, --silent Silent mode (don't output anything) -S, --show-error Show error. With -s, make curl show errors when they occur -L, --location Follow redirects (H) -o, --output FILE Write to FILE instead of stdout -O, --remote-name Write output to a file named as the remote file ``` ## files String replace: ``` apt-get install mlocate updatedb locate -S lsof -p ls --help | grep -E '[-][tr]\b' -r, --reverse reverse order while sorting extension -X, size -S, time -t, version -v -t sort by modification time, newest first mkdir -p /not/existing/folder cat > file <<'EOL' EOL ncdu --exclude='/root/data/*' / du -hcd 2 / | more du -a / | sort -n -r | head -n 20 ls -1 $PWD | wc -l # count files file /bin/ps ldd /bin/ps ``` ### find ``` find /home -iname tecmint.txt find $1 -iname $2 # find . ! -readable / -writable / -executabl # find . ! -perm -g=w find -regextype posix-extended -regex ".*[.](py|sh)" -exec chmod +x {} \; ``` ### grep ``` grep --color=auto -rn -P "${regex}" ${path} # -r, --recursive like --directories=recurse # -n, --line-number print line number with output lines # -P, --perl-regexp PATTERN is a Perl regular expression ``` ### compress/uncompress ``` gunzip file.gz tar -czvf name-of-archive.tar.gz /path/to/directory-or-file # Compress tar -tvf my-data.tar.gz '*.py' tar -zxvf toExtract.tar.gz tar -xvf {tarball.tar} {special_file} -C /target/directory tar -cf archive.tar foo bar # Create archive.tar from files foo and bar. tar -tvf archive.tar # List all files in archive.tar verbosely. tar -xf archive.tar # Extract all files from archive.tar. -t, --list list the contents of an archive -j, --bzip2 filter the archive through bzip2 -c, --create create a new archive -x, --extract, --get extract files from an archive -z, --gzip, --gunzip, --ungzip filter the archive through gzip -v, --verbose verbosely list files processed -f, --file=ARCHIVE use archive file or device ARCHIVE zip [options] zipfile files_list -r recurse into directories -x exclude the following names -v verbose operation/print version info -m move into zipfile (delete OS files) !! -d delete entries in zipfile !!! -u update: only changed or new files xz --decompress file.xz # -dgrub # unxz ``` ### rsync ``` rsync -aP -e "ssh -p $3" $1 root@$2 rsync -aP /root/_bin root@remote:/root rsync -aP -e "ssh -p 10220" /local root@remote:/dir --remove-source-files -v, --verbose increase verbosity -a, --archive archive mode; equals -rlptgoD (no -H,-A,-X) --no-OPTION turn off an implied OPTION (e.g. --no-D) -r, --recursive recurse into directories -l, --links copy symlinks as symlinks -p, --perms preserve permissions -o, --owner preserve owner (super-user only) -g, --group preserve group -D same as --devices --specials -t, --times preserve modification times -S, --sparse handle sparse files efficiently -e, --rsh=COMMAND specify the remote shell to use --partial keep partially transferred files --partial-dir=DIR put a partially transferred file into DIR -z, --compress compress file data during the transfer --progress show progress during transfer -P same as --partial --progress ``` ## history without line numbers ``` history | cut -c 8- -a append history lines from this session to the history file ~/.bash_history ``` ## hostname ``` hostnamectl set-hostname GZ2C8G ``` ## font ``` apt-get install xfonts-base ``` ## SELinux ``` getenforce semanage port -a -t mongod_port_t -p tcp 27017 ``` ## Dropbox ### link account `~/.dropbox-dist/dropboxd`\ dropboxd will create a \~/Dropbox folder and start synchronizing it after this step!\ unlink: ## Ubuntu snap run without `root` ### Proxy ``` vi /etc/environment systemctl restart snapd ``` ## JAVA\_HOME ``` echo export JAVA_HOME="/usr/lib/jvm/java-1.8.0-openjdk" >> /etc/profile ``` ## I18N & I10N ``` apt install -y locales-all locale -a dpkg-reconfigure locales yum grouplist chinese-support sudo apt-get install -y ttf-wqy-microhei #文泉驿-微米黑 sudo apt-get install -y ttf-wqy-zenhei #文泉驿-正黑 sudo apt-get install -y xfonts-wqy #文泉驿-点阵宋体 ``` ## Chrome ``` chromium --no-sandbox # start as root ``` ## AD ## cache diagnostics ``` git clone https://github.com/hoytech/vmtouch.git cd vmtouch && make && sudo make install Discovering which files your OS is caching Telling the OS to cache or evict certain files or regions of files Locking files into memory so the OS won't evict them Preserving virtual memory profile when failing over servers Keeping a "hot-standby" file-server Plotting filesystem cache usage over time Maintaining "soft quotas" of cache usage Speeding up batch/cron jobs ``` ## WOL ``` ethtool enp1s0 | grep Wake-on p (PHY activity) u (unicast activity) m (multicast activity) b (broadcast activity) g (magic packet activity) * a (ARP activity) d (disabled) ``` ## Tools - Online ## CPU ``` getconf LONG_BIT ``` ### check\_cpu\_core\_mapping same physical/core ID =》 simultaneous multi threads (SMTs) / HT ``` cat /proc/cpuinfo | grep -P 'processor|physical id|core id|^$' pip install walnut # pretty print for c in sorted([ ( int(c['processor']), int(c['physical id']), int(c['core id']) ) for c in cpu.dict().values()]): print c ``` ## USB Persistence ## kali x86/M1/Live/VM/WSL/etc: Docker: ## ssh Since 2022.1: * kali-tweaks -> Hardening -> Strong Security (the default) and Wide Compatibility ls -l /etc/ssh/ssh\_host\_\* systemctl disable regenerate-ssh-host-keys.service ### tools screenshots/cheat sheet: ## Video ``` dpkg -l amdgpu-pro glxinfo | grep direct GALLIUM_HUD=help glxgears ``` ## OpenCL installable client driver loader (ICD Loader) may expose multiple separate vendor installable client drivers (Vendor ICDs) for OpenCL. ``` sudo apt install ocl-icd-opencl-dev ``` ## zFCP device driver that supplements the Linux SCSI stack. ![](https://www.ibm.com/support/knowledgecenter/linuxonibm/com.ibm.linux.z.lgdd/lxzfcp.jpg) ## Diagram ![](https://upload.wikimedia.org/wikipedia/commons/thumb/7/7b/Free_and_open-source-software_display_servers_and_UI_toolkits.svg/1573px-Free_and_open-source-software_display_servers_and_UI_toolkits.svg.png) ## diskless ``` docker run --network=host -d leejoneshane/drbl-server ``` based on Scientific Linux 7 / CentOS 7 / Red Hat Enterprise Linux 7