Using the Linux Command Line
Using the Linux Command Line
● The CS50 IDE is a cloud-based machine running
Ubuntu, one of the many flavors of the Linux OS.
● Many modern Linux distributions have graphical
user interfaces (GUI) to allow easy mouse-based
navigation.
● Still, as a programmer you’ll likely be using your
terminal window frequently, and you can do many
of the same tasks with keyboard commands.
Using the Linux Command Line
● Let’s have a look at some of the most important of
these keyboard-based commands for working
within the IDE or any UNIX-based system.
Using the Linux Command Line
ls
● Short for “list”, this command will give you a readout of
all the files and folders in your current directory.
Using the Linux Command Line
cd <directory>
● Short for “change directory”, this command change your
current directory to <directory>, which you specify,
in your workspace or on your operating system.
● The shorthand name for the current directory is .
● The shorthand name for the parent directory of the
current directory is ..
● If ever curious about the name of the current directory,
though the terminal prompt will often tell you, you can
type pwd (present working directory).
Using the Linux Command Line
mkdir <directory>
● Short for “make directory”, this command will create a
new subdirectory called <directory> located in the
current directory.
Using the Linux Command Line
cp <source> <destination>
● Short for “copy”, this command will allow you to create a
duplicate of the file you specify as <source>, which it
will save in <destination>.
● If you wish to copy entire directories, you’ll need to
modify the command slightly:
cp –r <source directory> <destination directory>
The “-r” stands for recursive, and tells cp to dive down
into the directory and copy everything inside of it
(including any subdirectories it might contain).
Using the Linux Command Line
rm <file>
● Short for “remove”, this command will delete <file>
after it asks you to confirm (y/n) you want to delete it.
● You can skip the confirmation by typing:
rm –f <file>
But use at your own peril! There’s no undo.
● To delete entire directories you need to use the –r flag,
just as was the case with cp.
rm –r <directory>
● You can also combine the –r and –f flags into –rf.
Again, careful! There’s no undo!
Using the Linux Command Line
mv <source> <destination>
● Short for “move”, this command will allow you to
effectively rename a file, moving it from <source> to
<destination>.
Using the Linux Command Line
● To be sure, there are many more basic command
line utilities at your disposal, and we’ll discuss
many of them in the future in CS50.
● If you wish to explore other interesting ones before
we see them in the class, read up on:
chmod ln touch
rmdir man diff
sudo clear telnet
