Bash

BASH

Finding out which Linux Version running

cat /etc/issues

chsh

For some reason when using chsh -s /bin/bash I had to restart my computer to take it affect. What nicely worked was sudo usermod -s /usr/bin/zsh

sed

This command substitutes all colons in the PATH to newlines making the echo outpur easier to read

echo $PATH | sed s/\:/\\n/g

Replace all http to https in a file

sed -i 's/http/https/g' /etc/apt/sources.list

-i for in-place change

Append to a line

sed -i '\|^#AuthorizedKeysFile| s|$| /etc/ssh/authorized_keys/\%u|' sshd_config -i means do it in the file on the fly (Do it live) | means use | as a delimiter for sed, as we have / in the string we want to append ^#Auth# look for for the Line that starts with #AuthorizedKeysFile followed by a delimiter s for replace (substitue) $ for matching the end of the line /etc/ssh the string we want to append /%u an escaped %, as %u is a variable for user interpreted by ssh sshd_config the file we want to change

Updating Value in a Yaml File

sed -i "s/key: .*/key: \"$B64\"/g" file.yaml

This updates the Value of key with whatever is stored in the Variable $B64

grep

find something recusively in the files of a folder grep <path> -rne <pattern> -n shows line number -e defines the pattern to look for -r sets recursively See here

find

Find files in a folder with excluding a path

find . -path ./exclude/path -prune -o -iname "*pattern*" -print

Find all files ending in .md and find the lines that contain django in those files.

find . -type f -name "*.md" -exec grep "{}" -re django  \;

for loop

Find all Files in current directory where the filesize is bigger the 50Kb and copy them into another directory

for filename in * ; do size=`wc -l "$filename" | awk '{ print $1 }'` &&  if [ "$size" -gt 50 ]; then cp "$filename" anotherdir; fi;  done

Create 10 folders with the number and _stringname as the folder name and do something with all results from find.

for item in {1..10} ; do mkdir ${item}_stringname ; done
for i in $(find . -iname "*.tf"); do file $i && grep $i -e "ecr" ; done

rename

Remove string from the beginning of all files in the current directory using rename

rename 's/string//;' 

use rename for my kindle exports

rename 's/[()]//g' *
rename 's/ /_/g' * 

du

Getting disk usage with excluding one or more pathes

du --exclude=path1 --exclude=path2 --exclude=path3 -sh *

certbot

I use this to install certbot from letsencrypt on Debian 9.3(stretch) with nginx

mkdir -p /usr/bin/certbot
cd /usr/bin/certbot
sudo wget https://dl.eff.org/certbot-auto
chmod +x certbot-auto
./certbot-auto --installer nginx

Making it update every 2nd month and log into /var/log/certbot/certbot.log

mkdir /var/log/certbot
crontab -e
1 1 1 */2 * sh /usr/bin/certbot/certbot-auto renew >> /var/log/certbot/certbot.log 2>&1

turning off screen

Turning off the screen on Linux Mint 18.2 Sonya 4.13.0-41-generic #46~16.04.1-Ubuntu

sudo apt-get install vbetool
sudo vbetool dpms off/on

CommandLine Tools

Installing colorls

sudo apt-get install ruby2.3-dev
sudo gem install colorls
echo "alias colorls='$HOME/.gem/ruby/2.6.0/bin/colorls'" >> ~/.zshrc
echo "alias la='lc -ah'" >> ~/.zshrc
l -lS -r

sort Files in reversed order by size, i.e. biggest files on bottome hence easy to see

Install bat

Bat is more eye-friendly cat alternative, on Github. Replace the release number down there with the latest from the Release Page Release.

wget https://github.com/sharkdp/bat/releases/download/v0.16.0/bat_0.16.0_amd64.deb
sudo dpkg -i bat_0.16.0_amd64.deb
echo "alias b=`which batcat`" >> ~/.zshrc

fuzzyfind

On fzf

sudo apt-get install fzf

autojump

On autojump. Autojump needs to be sourced.

sudo apt install autojump
echo "source /usr/share/autojump/autojump.sh" >> ~/.zshrc

Pseudo stresstest forkbomb

t(){for ((i=1; i<=100; i++ )) { (curl www.URL.com > /dev/null  ; echo $i );next} & ; t }

Only blows your system without putting real stress on a server, but might get you banned or blocked.

ZSH

Install, verify zsh location and change it to default shell

sudo apt-get install zsh
whereis zsh
chsh -s /usr/bin/zsh wolle

Oh-my-zsh

Documentation is here Install Oh-my-zsh first because it comes with its own .zshrc file

sh -c "$(curl -fsSL https://raw.github.com/ohmyzsh/ohmyzsh/master/tools/install.sh)"

Syntax highlighting

More here

git clone https://github.com/zsh-users/zsh-syntax-highlighting.git ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-syntax-highlighting

Spaceship prompt

To make things look nice, more info here

git clone https://github.com/spaceship-prompt/spaceship-prompt.git "$ZSH_CUSTOM/themes/spaceship-prompt" --depth=1
ln -s "$ZSH_CUSTOM/themes/spaceship-prompt/spaceship.zsh-theme" "$ZSH_CUSTOM/themes/spaceship.zsh-theme"

ZSH Completions

more info here

  git clone https://github.com/zsh-users/zsh-completions ${ZSH_CUSTOM:-${ZSH:-~/.oh-my-zsh}/custom}/plugins/zsh-completions

ZSH autosuggestions

See Documentation here

git clone https://github.com/zsh-users/zsh-autosuggestions ${ZSH_CUSTOM:-~/.oh-my-zsh/custom}/plugins/zsh-autosuggestions

Colorls

Install buildtools, buildessentials, ruby and then a too complicated bash expression that should work independent of ruby version (famous last words).

sudo apt-get install build-essential bison openssl libreadline6-dev curl git-core zlib1g zlib1g-dev libssl-dev libyaml-dev libxml2-dev autoconf libc6-dev ncurses-dev automake libtool
sudo apt install ruby ruby-dev gcc make
gem install colorls --user-install
alias colorls="`gem env | grep "USER INSTALLATION DIRECTORY" | awk '{ print $5 }'`/bin/colorls"

Auto Sugges

Tmux

Creating a new session tmux new -s session-name Leaving/detaching from a session press<prefix> : and type detach Listing existing sessions tmux ls Entering/attaching to an existing session tmux attach -s session-name/session-number

Veracrypt

This downloads Veracrypt from Vercrypt.fr Version 1.23 the latest as of October 2019, unpacks it and installs it. Careful there is some user input neccessary.

wget https://launchpad.net/veracrypt/trunk/1.23/+download/veracrypt-1.23-setup.tar.bz2
tar -xf veracrypt-1.23-setup.tar.bz2
sudo bash veracrypt-1.23-setup-gui-x641