Here are some basic Linux commands to get you up and running, or a quick cheat sheet. Great for when working on a Raspberry Pi or any other single board computers which use Linux commands such as Beagleboard / Beaglebone, Asus Tinker Board and many others.
FILES & NAVIGATING
- ls – directory listing (list all files/folders on current directory)
- ls -l – directory listing, with the file details in a formatted way, easier to read
- ls -la – directory listing the same as ls -l but this will also display hidden files
- cd dir – change directory to dir (dir will be directory name)
- cd .. – change to the parent directory
- cd ../dir – change to dir in the parent directory (dir is replaced with a specific directory)
- cd – change to the home directory
- pwd – show current directory
- mkdir dir – create a directory dir (replace dir with your chosen name)
- rm file – delete a file
- rm -f dir – force remove a file
- rm -r dir – delete directory dir
- rm -rf dir – remove directory dir
- rm -rf / – if run by a superuser, will delete every file on the system (DO NOT DO THIS)
- cp file1 file2 – copy file1 to file2
- mv file1 file2 – rename file1 to file2
- mv file1 dir/file2 – move file1 to dir as file2
- touch file – create or update file
- cat file – output contents of a file
- cat > file – write standard input into a file
- cat >> file – append standard input into a file
- tail -f file – output contents of a file as it grows
NETWORKING
- ping host – ping host
- whois domain – get whois for a domain
- dig domain – get DNS for domain
- dig -x host – reserve lookup host
- wget file – download file
- wget -c file – continue a stopped download
- wget -r url – recursively download files from a URL
- curl url – outputs the webpage from a URL
- curl -o hello.html URL – writes the page to hello.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
PROCESSES
- ps – display currently active processes
- ps aux – detailed outputs
- kill pid – kill process with process id (pid)
- killall proc – kill all processes named proc
SYSTEM INFORMATION
- date – show current date / time
- uptime – show uptime
- whoami – current logged in user
- w – display who is online
- cat /proc/cpuinfo – displays CPU information
- cat /proc/meminfo – displays memory information
- free – show memory and swap usage
- du – show directory space usage
- du -sh – displays readable sizes in GB
- df – show disk usage
- uname -a – show all kernel information. Alternatively, if you only want specific information, you can change the “-a” switch to any of these for different information: “-m, -r, -v, -n”
- sudo lshw – calls the lshw tool which gathers vast information about the computer’s hardware such as CPU, disks, memory, USB controllers etc
- lscpu – display CPU information
- lsusb – displays USB controllers information
- lspci – displays PCI devices information
COMPRESSING
- tar cf file.tar files – tar files into file.tar
- tar xf file.tar – untar into a current directory
- tar tf file.tar – show contents of archive
- Switches:
- c – create an archive
- t – table of contents
- x – extract
- z – use zip/gzip
- f – specify a filename
- j – bzip2 compression
- w – ask for confirmation
- k – do not overwrite
- T – files from a file
- v – verbose
- Switches:
PERMISSIONS
- chmod octal file – change permissions of a file
- 4 – read (r)
- 2 – write (w)
- 1 – execute (x)
order owner/group/world
- chmod 777 -rwx for everyone
- chmod 755 – rw for the owner, rx for group world
OTHER USEFUL COMMANDS
- grep pattern files – search in files for a pattern
- grep -r pattern dir – search for pattern recursively in dir
- locate file – find all instances of a file
- whereis app – show possible locations of app
- man command – show manual page for a command
