Linux Server Configuration

1.3.3 Creating Directory: mkdir

The mkdir command makes new directory under an existing directory. For example to create a directory for storing music files:

$ mkdir musics

To delete an empty directory we use rmdir command.

$ rmdir OldMusics

We use rm with –r option to delete directories and all the files (recursively) they contain.

$ rm -r OldMusics

1.3.4 Viewing Hidden Files And Directories: ls -a

The special . and .. directories don’t show up when we do ls. They are hidden files

Files whose name starts with a dot ( . ) are considered hidden.

Make ls to list all files, even the hidden ones, by giving the –a option:

$ ls -a

. .. .bashrc .profile report.doc

1.4 Working With Files

This section describes utilities that copy, move, print, search through, display, sort, and compare files.

1.4.1 Display A Text File: cat

The cat utility displays the contents of a text file. The name of the command is derived from catenate, which means to join together, one after the other. A convenient way to display the contents of a file to the screen is by giving the command cat, followed by a SPACE and the filename. Figure 1.5.1 shows cat displaying the contents of practice. This figure shows the difference between the ls and cat utilities: The ls utility displays the name of a file, whereas cat displays the contents of a file.

1.4.2 Delete A File: rm

The rm (remove) utility deletes a file. Figure 1 shows rm deleting the file named practice. After rm deletes the file, ls and cat show that practice is no longer in the directory. The ls utility does not list its filename, and cat says that no such file exists.

Use rm carefully.
$ ls
practice
$ cat practice
This is a small file that I created
with a text editor.
$ rm practice
$ ls
$ cat practice
cat: practice: No such file or directory
$