The Basics

• ls -la list all contents of a directory including hidden files
• cd [directory] move to the specified directory, cd /Applications will move to your applications folder
• mv [file1] [file2] mv is able to rename files or move them, depending on usage
• cp [file] [destination] copies a file to either a new filename or destination
• cat [file] | more display contents of a file screen by screen by ‘piping’ the contents through more
• touch [file] creates a file with the given name, eg: touch test.txt will create a blank text file
• top display a continuously updated list of all running processes, including memory and cpu usage, PID is the process ID which you would use to kill a process
• ps -aux list all processes running from all users, -ux will list only processes of current user
• kill -9 [pid] kill the specified process id (basically force quit for the command line)
• rm [file] rm removes the specified file or directory, there is no warning so use with caution
• ping [ip] determine network latency by pinging another host

General Usability Tips

• Use the tab key, the tab key will autocomplete directories and filenames for you
• Enable colored terminal, this makes it easier to browse through large amounts of files
• If a command confuses you, try running it with the –help flag, which will often display basic instructions on the given command
• Remember manual pages exist on many commands as well, access them by typing man [command], eg: man ping
• If the output of a command flies by you and is too much to fit on one screen, try piping it through more, like so: ls -la |more this will enable you to see the output a screen at a time
• You can export the contents of a file, output of a command, and results of a script to a text file using the alligators (improper terminology, excuse my forgetfulness), eg: ls -la /Applications > applist.txt
• If you’ve ever noticed your CPU load skyrocket inappropriately, a good place to find the errant process is with the top command, use top in conjection with kill to find the process ID and kill the CPU hog
• Don’t be afraid to get your hands dirty!