# Linux Administration

## Linux Administration

& This operator allows you to run commands in the background of your terminal. && This operator allows you to combine multiple commands together in one line of your terminal.

> This operator is a redirector - meaning that we can take the output from a command (such as using cat to output a file) and direct it elsewhere.
>
> >

This operator does the same function of the > operator but appends the output rather than replacing (meaning nothing is overwritten). ls -lh: file permissions

<https://vim.rtorr.com/>

python3 -m http.server scp, wget, curl ps aux ip a top kill %pid systemctl start Ctrl + Z: background process &: background process fg: bring to foreground cron/crontabs <https://crontab-generator.org/> <https://crontab.guru/> Get user's shell: grep "^$USER" /etc/passwd Get current linux version: cat /etc/os-release View Message of the Day (MOTD): sudo nano /etc/motd // cat /etc/update-motd.d/00-header SSH keys are stored in this directory by default: \~/. ssh/id\_rsa

## Get Public IP

curl ifconfig.me

curl wtfismyip.com/json

## Get Bash History

navigate to home directory cat .bash\_history

## Show user id and current user

id whoami

## Search a file for a keyword

grep 'word' filename

## Print system environment variables

env

## Rerun last command as sudo

sudo !!

## Navigate to home directory

cd \~ cd

ps

sed

awk

<https://betterprogramming.pub/15-essential-linux-command-line-tips-and-tricks-95e2bfa2890f>

base\_64 decode openssl\_decrpt

<https://gist.github.com/johnnypea/b0cd77e5734d65691fa21d93274b305b>