Linux

List Files. The ls command will list the files in a directory. By default, ($ ls) lists the files in your current directory. You can also list files recursively; that is, list all files in directories inside the current directory with ($ ls ­-R). ls can also list files in another directory if you specify the directory. For example, ($ ls scratch) from your home directory will list all your files in your scratch directory.

Change Directory. The cd command changes to another directory. For example, cd/home/yourNETID/scratch will take you to your scratch directory. By default, ($ cd) changes to your user home directory. Using ($ cd ..) will move you upwards into the parent directory of your current directory.

Move Files. The mv command moves a file to a new location. This is also the command you’ll use  to rename files. For example, ($ mv file newfile) would take the file named “file” in the current directory and move it (rename it) to the file named “newfile” into your current directory.

Copy Files. The cp command works the same way as the mv command, except it copies the original files instead of moving them. You can also do a recursive copy with ($ cp ­-r). This copies a directory and all files inside it to a new location. For example, ($ cp filename scratch/) places a copy of the “filename” file from your home to your scratch directory.

Remove Files. The rm command removes files. Be careful with this command! rm doesn’t ask you for confirmation by default, but you can use ($ rm filename) for a more interactive experience. For example, ($ rm -i filename) would ask for prompt you first before it deletes the file with “filename” in your current directory.

Make Directory. The mkdir command makes a new directory. ($ mkdir example) will make a directory with the name “example” in the current directory.

Remove Directory. ($ rmdir directory) would delete the directory named “directory” in the current directory. For the case where the directory isn’t empty, ($ rm ­-r) directory would delete the directory and all the files in it. Be careful with this command.

Create Empty Files. The touch command creates an empty file.
For example, ($ touch example) creates an empty file named “example” in the current directory.

Present Working Directory ($ pwd) will display the full path of your current directory.

Tab Completion is capable of helping you type path names. If you type a partial command and hit the [Tab] key, it will try and autocomplete what you were trying to type. If it can't guess what you are trying to type, it will beep at you. If you hit [Tab] again, it will give you a list of matches to select from. Here's an example of using tab completion.