/shell-magic

Primary LanguageShell

Shell-Magic für Anfänger

touch

touch foo.txt # creates file or updates access and modification time
touch foo{1..10}.JPG
  • mit -r kann ein anderes File referenziert werden, um dessen Zeiten zu verwenden, statt der aktuellen
  • mit -d kann die Zeit direkt angegeben werden

screen

screen -S long ./long_running_script.sh
  • ctrl+a ctrl+d # detach
  • screen -r [name] # reattach
  • screen -ls # list screen sessions

tmux

tmux new-session -s name  # create a new session with the identifier - here 'name'
tmux ls # list all active sessions
tmux attach -t name # attach to an active session identified by its 'name'
# detach from a session using [CTRL + B] + [D]
# create a new window inside the current session [CTRL + B] + [C]
tmux kill-server # kill the tmux server & all client instances

jq

jq . example.json # pretty print
jq '.Inhaber | { Name, Vorname }' example.json
jq '{ "cardnumber": .Nummer, "issuer": .Herausgeber, "name": .Inhaber.Name, "lastname": .Inhaber.Name }' example.json

sort && uniq && wc

echo "foo\nbar\nbar\nbaz\nbar"
echo "foo\nbar\nbar\nbaz\nbar" | sort
echo "foo\nbar\nbar\nbaz\nbar" | sort | uniq -c
echo "foo\nbar\nbar\nbaz\nbar" | wc -l

for && while

for f in *.JPG; do mv $f ${f/.JPG/.jpg}; done

convert

convert images

convert foo.png foo.jpg
convert old.png new.png  +append compare.png

ssh{,-config}

ssh -p 2222 a128707@192.168.2.123
# only use specified keys
IdentitiesOnly yes

# use sockets
Host *
     ControlMaster auto
     ControlPath ~/.ssh/socket-%r@%h:%p

# config our server
Host braindump-server
     Hostname 192.168.2.123
     User a128707
     Port 2222
     IdentityFile ~/.ssh/arconsis

mosh -> MObile SHell

  • handels bad connections
  • resumes shell-sessions, even in different networks
  • shows typed characters without delay

sshuttle

  • can be used kind of like a VPN
  • uses ssh-portforwarding
  • only forwards TCP-Traffic
  • only needs permissions to execute python on target system

jobs (ctrl+z,&,fg)

./long_running_script.sh
<ctrl+z>
jobs
fg %1

redirect outputs

stdout -> Datei

programm > Datei.txt

stderr -> Datei

programm 2> Datei.txt

stdout UND stderr -> Datei

programm &> Datei.txt

stdout -> stderr

programm 1>&2

stderr -> stdout

programm 2>&1

write files with echo

echo '#!/bin/sh' > script.sh
echo 'echo "Hello World"' >> script.sh
chmod +x script.sh && ./script.sh

find

find . -name "*.jpg"
find . -mmin -5 # find files modified in the last 5 minutes
find . -ctime -1 # find files created in the last day
find . -atime +7 # find files last accessed more than a week ago

find ./src/ -name "*.java" -exec wc -l {} \; | sort # find all java-files, count number of lines and sort the result
  • {+,-}{a,c,m}min für Zeit in Minuten (access, create, modified)
  • {+,-}{a,c,m}time für Zeit in Tagen

man/tldr

https://tldr.sh/

man find
tldr find

grep

grep -E '([[:digit:]]{4}-){3}[[:digit:]]{4}' example.json

netcat && socat

nc -l -p 8000 # listen on (tcp) port 8000

curl && httpie

https://github.com/jakubroztocil/httpie

curl -s -H "Content-Type: application/json" \
	-XPOST http://localhost:8000 \
	-H 'Header: Value'
	--data '{"username":"YOUR.USERNAME","password":"YOUR.PASSWORD"}'

http POST :8000 \
	'Header: Value' \
	'username=YOUR.USERNAME' \
	'password=YOUR.PASSWORD'

Different Separators -> Different Type

  • : HTTP Headers
  • == URL-Parameters
  • = JSON or Form-Data fields

alias

alias # prints all defined aliases
alias foo="ls -l" # defines an alias (only for current shell)