Getting Down with ...: Lesson n

Text files and text editing

Text files are files in our file system that contain only plain text. Plain text represents characters without any information about their appearance, such as whether they are bold, centered, in a fancy font, and so forth. Plain text files do not contain this information, just the characters of the plain text itself. The source files of web pages and computer programs are examples of common files which are written in plain text.

The basic operations we need to perform in working with text files include creating, viewing, modifying and deleting them. We will learn to delete files in the next lesson. In this lesson we are going to learn to create, view, and modify them, a process referred to as editing the file. A program called a text editor is designed specifically for the purpose of editing text.

GNU nano

GNU nano is a simple, easy to use command line text editor. To start nano, type nano at the unix command prompt:

$ nano

The program will load and you will see a screen that looks like this:

nano start

The bottom two lines of the screen provide help on using nano. The ^ character represents the control key (usually marked with Ctrl) on your keyboard. Even though the letters that follow the ^ character appear as capital letters, you do not use the shift key when typing them.

Write Out in nano means to save the text inside the nano screen to a file. The following screen shot shows what the nano screen looks like after the user has pressed Ctrl+o (hold down the Ctrl while pressing the o key - this is what ^O represents in the help at the bottom) and is about to write out two lines of text to a file named firstnano.txt:

firstnano.txt

Pressing the Enter key will now save (write out) the file. Pressing Ctrl+x will now exit nano. Nano has many other features, some of which you can read about in A Beginner’s Guide Using the GNU nano Text Editor on Linux. You will be introduced to the much more powerful vim editor in a few lessons, however, so we will only need the most basic commands here.

Exercises:

Type the following at the unix command prompt:
```
$ nano word.txt
```
This will create the text file, word.txt, in a nano edit session. Add the following text to the file:
```
love
```
Save the file and exit nano. Run the ls command and confirm that you see word.txt among the listing.
Type the following at the unix command prompt:
```
$ nano fruits.txt
```
Add the following text to the file:
```
apples, bananas, grapes, oranges, pears, and strawberries
```
Save the file and exit nano. Type the following at the unix command prompt:
```
$ ls -l
```
You should see one line that looks something like this:
```
-rw-rw-r--  1 username username   58 Sep 28 22:16 fruits.txt
```
The 58 after the owner and group name is the size of the file in bytes. Since each character is one byte, this file has 58 characters. You'll only count 57. The last one is the invisible end of file character. Confirm that the word.txt file you created in the previous exercise has size 5.

Use nano to edit a file named hello.html with the following contents:

<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="utf-8">
<title>Hello World!</title>
</head>
<body>
<h1>Hello World!</h1>

</body>
</html>

Download fruitlist.txt. Then run:
```
$ nano fruitlist.txt
```
to see its contents.

Lesson n:

Text files and text editing

GNU nano

Exercises: