Bash Commands You Should Know!
Handy Linux Terminal commands and tricks you should know!
Contents:
Text Handling
Networking
Storage
Tricks
Other
Text Handling
head -5
Output the first 5 lines of text
cat
cat file.txt
Display the contents of a file
tail -5
Output the last 5 lines of text
wc
Wordcount Utility
Output: Line | Words | Characters
grep
Handy search utility for searching plain-text data
$ ps aux | grep ssh - This will search all running processes for ones that contain 'ssh'
Networking
ip addr
Display network interfaces
*The replacement for ifconfig
cat /proc/net/arp
Display local network devices | Just arp will work on most distros
netstat -pnltu
View open TCP/UDP Ports | Flag Options
sudo may be needed to view program names.
curl ifconfig.me
Find out your External IP using ifconfig.me
netstat -natp
View current network connections
Storage
df -h
View disk usage | -h (Human readable)
du -sh *
View the size of all directories
Tricks
!!
Repeat last command
sudo !!
Repeat last command using sudo
!$
Passing Arguments from Previous Command
$HOME
Enviromental Variable for your home directory
Other
cal
Display the current month, with the day highlighted
ps aux
View all running processes | Kill process with kill <PID>
Parameter Expansion With {a,b}
Instead of $ mv README.txt README.md use mv README.{txt,md}
$ echo pre{1,2,3}fix
Output: pre1fix pre2fix pre3fix
^old^new
$ ssh ubuntu@198.compute.com
Replace ubuntu in the last command with bob
$ ^ubuntu^bob
ssh bob@198.compute.com
Have another? Send it over!