Basic CLI

Commands

Linux has many useful and powerful tools right in the command line. In this sections we have provided examples for the most common commands you will need but you can find more in depth explanations of most Linux commands by using the man command. For example, man mv will open a page in your terminal showing usage and explanations of every option flag you can give the mv command.

ls - list the files and directories inside your current directory. 

ls

ls command being used to display items in the users current d

For this command, you do not need any other parameters for it to work. However, you may want to list items differently. One way of doing this is by typing ls -l. This will present the same files you find with a simple ls in a list format including more information. What you see when you run this command may be daunting before you know what this is showing you. For now, we will focus on the easy list looking format of the names to the far right. If the first character shown on the far left is a d, then the name you are looking at is a directory (aka, a folder). For more information on what the rest of the output means, see Permissions.

ls -l being used to display the full information for items in the directory.

Another command you can use to see everything you have in your folder (including hidden files) is the ls -a command.

ls - a being used to display hidden files in your directory

You may have seen another command flag -la used with ls. This combines the two previously explained flags, and will list all files and folders in the directory you are in. The first two folders shown are “.” and “..” and this signifies the your current directory (“.”) and your parent or previous directory (“..”). This list also includes hidden files, which are denoted by a “.” at the front of a file name. Explanation on what these are can be found later in this section.

ls -la being used to show hidden files with long format for the items.

pwd - print the name of your current working directory.

cd - change directory, move into other folders so that you can access the information there. 

cd folderName

For example, cd ./folderName will move location from your current location (signified by the dot “.”) to the location of folderName. However, if you are already in the directory of the folder you want to be in, you can also simply write cd folderName.

A terminal session where pwd and cd are used to navigate the session.

On the other hand, if you are looking to move into a folder that is beyond the folder you are already in, you can type out the specific directory path. For example, you might type something like this cd /home/folderName. Another way of getting to a completely different folder, you can cd back to the folder you would like to move from. To accomplish this, you would change your directory back to the previous folder you came from by typing cd ...

cd followed by a file path being used to navigate to the exact directory.

mkdir - make directory, make a new folder.

mkdir followed a name argument being used to a create a new folder.

mv - move a file or directory from one place to another. Can also be used to rename a file. 

mv <location of source> <location of destination>

mv being used to put a folder into a folder

And an example of using the mv command to rename a file.

mv source_file other_file to rename source to other

rm - remove file or directory as described by telling the command line the location of the file or directory you would like to remove.

To remove a file, simply type

rm filename.extenstion

To remove a directory will require a flag, depending on whether you have information in the directory already. While the following line works only on empty directories, it might be nice for you to see if you are about to lose something important, so type

rm -d directory

This will give a warning if there is anything in your folder and then you have the chance to go in and see if you truly want it all removed. If you are positive about all the information going away, one way to do it is

rm -r directory

rm -r being used to recursively delete a directory

However, this is just one way. In fact, many of these commands are only one way of accomplishing a task. This is just to get you started but there are boundless nuances in accomplishing a task.

[command] *.[file extension]

The wildcard character is used to call a command on specific files. For example when you say ls *.docx that means you want to list all and only files of type .docx

a wildcard being used to move all files of .docx type into a subfolder.

You can also use this character to call commands on filenames.

a wildcard being used to move all files with a certain string into a subfolder.

cp <file source> <file destination>

With the cp command you can copy files from the command line from one folder to another. Here we have an example of using the command with the wildcard.

cp being used with a wildcard to copy all 'essays' from one folder to another.