raspi-config                    # Raspberry Pi configuration tool
raspistill -o cam.jpg           # Take a photo output to cam.jpg
raspistill -vf -hf -o cam.jpg   # Take a photo with vertical flip, horizontal flip
raspivid -t 5000 -o test.h264   # record 5 seconds of video
gpio -g mode <pin> up           # turn on the pull up resistor for pin
gpio -g mode <pin> down         # turn off the pull up resistor for pin
gpio -g write <pin> 0/1         # Write 0 (off) or 1 (on) to pin
gpio -g read <pin>              # Read and print the value of the pin
gpio -g readall                 # Read all pins and print their numbers

gpio -g mode 15 output
gpio -g write 15 1
sleep 2
gpio -g write 15 0

gpio -g mode 14 in
gpio -g read 14

ls -la                  # listing of files in current folder 
cd folder               # change directory to folder 
cd ..                   # change to parent directory 
cd ~                    # change to home directory 
pwd                     # print working directory 
mkdir folder            # make directory  
rm file                 # remove file/folder
rm -f file              # force remove file/folder 
rm -r folder            # recursively remove folder & it's contents 
cp file1 file2          # copy filel to file2 
mv file1 file2          # move(rename) filel to file2 
mv file1 dir/file2      # move(rename) file1 to dir as file2 
touch file              # create or update file 
cat file                # output contents of file 
cat > file              # write standard input into file 
cat >> file             # append standard input into file 
tail -f file            # output contents of file as it grows 

date                    # show current date/tvrne 
uptime                  # show uptime 
whoami                  # who you're logged in as 
w                       # display who is online 
cat /proc/cpujnfo       # display cpu info 
cat /proc/meminfo       # memory info 
cat /proc/partitions    # info size and number of partitions
cat /proc/version       # What version of Pi
free                    # show memory and swap usage 
du                      # show directory spaco usage 
du -sh                  # displays readable sizes in GB 
df -h                   # show disk usage 
uname-a                 # show kernel config 
vcgencmd measure_temp   # show CPU temperature
free -o -h              # show available system memory
lsusb                   # show attached USB devices

tar cf file.tar files   # tar files into filetar 
tar xf file.tar         # untar into current directory 
tar tf file.tar         # show contents of archive 

ping www.host.com       # ping host
whois domain            # get whois for domain 
dig domain              # get DNS for domain 
dig -x host             # reserve lookup host 
wget file               # download file 
wget -c file            # continue stopped download 
wget -r url             # recurively download files from url 
curl url                # outputs tho webpage from url 
curl -o meh.html url    # writes the page to meh.html 
ssh user@host           # connect to host as user 
ssh-p port user@host    # connect using port 
ssh-D user@host         # connect & use bind port 
netcat                  # Network scanning 
top                     # Top processes using CPU, RAM etc
iwconfig                # Show wifi network connected to
ifconfig                # Show network connection info
iwlist wlan0 scan       # Show currently available networks
nmap                    # Show connected devices on your network
hostname -I             # Show IP address of your device
netstat -l              # display all listening connections
netstat -lpc            # display all listening connections, update continuously

# Download file
wget https://address.com/file
# SSH login to remote system
ssh <user>@<address>
# Transfer file to remote system and specified location
scp test.txt user@192.168.1.201:/home/user/     

sudo service nginx restart  # restart the (for example) nginx service
sudo service nginx start    # start the (for example) nginx service
sudo service nginx stop     # stop the (for example) nginx service
ps aux                      # display currently active processes 
kill pid                    # kill process with process id (pid) 
killall proc                # kill all processes named proc 
dmesg                       # show you every event that happened in the start sequence

chmod 777 file          # rwx for everyone
chmod 755 file          # rwx for owner, rx for group & world
chown userid file       # change owner of file
chown -R userid folder  # change owner of folder & it's contents

sudo apt-get update             # Collect info on pending updates
sudo apt-get upgrade            # Upgrade all installed packages
sudo apt-get dist-upgrade       # Upgrade the distribution if available
sudo rpi-update                 # Update the firmware (can break stuff!)
sudo apt-get install <app>      # Install the specified app