Linux

Commands

This page contains most commonly used Linux commands that will be handy while programming with Raspberry Pi.

Note that the idea is not to teach Linux commands extensively but instead to give users of Raspberry Pi a quick head start. This gives user a springboard for future research.

File management

Command	Description
ls	Shows the contents of the directory
ls -a	Shows hidden files
pwd	present working directory (default is /home/pi)
cd ..	Go to parent directory
cd home	Go inside home directory (home directory should be in current location)
mkdir java	Make a directory called java
rm test.txt	Remove the file called test.txt
rm -f test.txt	Force remove the file called test.txt
rm -r java	Remove directory called java
chmod 777 java	read(4)-write(2)-execute(1) permission to User(7)Member(7)Others(7)
cp -r test java	Copies directory called test to a directory called java (created if not present)
more Led.py	Displays the contents of file called Led.py
head Led.py	Displays first 10 lines of the contents of a file called Led.py
tail Led.py	Displays last 10 lines of the contents of a file called Led.py
cat Led.py	Displays the contents of file Led.py on screen
cat f1.py > f3.py	Copies contents (try cat f1.txt f2.txt | sort > f3.txt) data in sorted order!
mv f1.py ../	Moves file f1.py to parent directory

System Information

Command	Description
man chmod	Shows the manual of the command called chmod
df	Shows disk usage
whoami	Shows Login ID
date	Shows current date
cal	Shows current month's calendar
mv java jre	Rename the directory called java as jre
ping 10.0.0.138	pings the host names pi and outputs the info (use CTRL+Z to stop)
top	running programs and theior IDs
ps	current active processes and their PID
lsusb	Information about the USB devices connected to Pi
echo hello	Outputs 'hello' on screen. This command is useful for debugging
date -s (string)	sudo date -s "Thu May  4 12:20:46 AEST 2017"

Searching 

Command	Description
grep GPIO Led.py	Search for GPIO in file called Led.py; if found then opens files & highlight them
grep -r bob java	Search for bob in all the files within the directory called java
ls | grep py	Search for the sub-string 'py' in the output of ls command
sudo find data.txt	Search current directory for the file called data.txt
ls | more	Display contents one page at a time (try also ls | less)
clear	Clears the screen

Keyboard Shortcuts 

Command	Description
CTRL+Z	Kills the current command
CTRL+D or exit	Logout
CTRL+C	Halts
CTRL+R	Reverse-i-search. Type first few characters to go to recent used command

Sudo

Command	Description
sudo reboot	Runs Rebootcommand as superuser
sudo nano bob.txt	Makes (Opens) a file called bob.txt in root folder and can edit it
su	Asks for root password (default = root), (note: CTRL+D to logout)
sudo passwd root	Reset new password for root