Ubuntu 22.04 Command Line Editors

Command Line Editors

A command line editor is a type of software program that allows users to create and edit text files directly from a command line interface. This means that instead of using a graphical user interface, users interact with the editor through a text-based interface.

Command line editors are often used by programmers and system administrators who need to work with text files in a terminal environment. They are particularly useful for tasks such as modifying configuration files, writing scripts, and editing code.

Some popular command line editors include Vi, Nano, and Emacs. Each editor has its own set of features and commands, and users often have strong preferences for which one they prefer to use.

One advantage of using a command line editor is that it allows for efficient editing of text files without the need for a separate program or application. Additionally, command line editors can be used over a network connection, which can be useful for remote administration and collaboration.

However, command line editors do require some familiarity with basic command line navigation and editing commands, which can be daunting for users who are not accustomed to working in a terminal environment. Nonetheless, mastering a command line editor can be a valuable skill for anyone who works with text files on a regular basis.

VI

vi is a text editor that is built into most Linux distributions. It is a command-line based editor that can be used to create and modify text files.

vi has two main modes:

• Command mode: This is the default mode when you open a file in "vi". In command mode, you can navigate around the file, make edits, and execute commands. You cannot enter text in this mode.

• Insert mode: In insert mode, you can enter text into the file. To enter insert mode, you need to switch from command mode to insert mode.

Here's how to switch between the two modes in "vi":

• To switch from command mode to insert mode, press the "i" key. This will allow you to start typing text into the file.

• To switch from insert mode back to command mode, press the "Esc" key.

While in command mode, you can use various commands to navigate around the file and perform various editing tasks, such as deleting or copying text. Here are some examples of commands you can use in command mode:

h: Move the cursor left
j: Move the cursor down
k: Move the cursor up
l: Move the cursor right
dd: Delete the current line
yy: Copy the current line
p: Paste the last line that was copied or deleted

There are many more commands available in "vi". You can access a list of commands by typing :help in command mode.

It's important to note that "vi" can be a bit confusing for new users, especially since it requires memorizing different commands to navigate and edit files. However, once you get the hang of it, "vi" can be a very powerful and efficient tool for editing text files.

nano

Nano is a simple, easy-to-use text editor that is available on most Linux distributions. It is designed to be user-friendly and intuitive, making it a good choice for beginners who are new to Linux.

Here are some examples of how to use Nano:

To open a file with Nano, type the following command in a terminal:

nano filename
This will open the file "filename" in the Nano editor.

To enter text in Nano, simply start typing. Text will appear at the cursor location.

To save changes to a file, press the Ctrl and O keys together. This will bring up the save prompt. Type in the name of the file you want to save and press "Enter".

To exit Nano, press the Ctrl and X keys together. If there are unsaved changes, Nano will prompt you to save them before exiting.

To copy text in Nano, use the Alt and 6 keys together to set a mark at the beginning of the text you want to copy, then move the cursor to the end of the text you want to copy. Press the Ctrl and K keys together to cut the text to the clipboard. Move the cursor to the location where you want to paste the text, and press the Ctrl and U keys together to paste the text.

To search for text in Nano, press the Ctrl and W keys together. This will bring up the search prompt. Type in the text you want to search for and press "Enter". Nano will search the file for the text and highlight the first occurrence.

To navigate through a file in Nano, use the arrow keys to move the cursor up, down, left, or right. Use the Page Up and Page Down keys to move the cursor up or down one page at a time.

Nano is a great option for users who prefer a simple, easy-to-use text editor that doesn't require memorizing complicated commands.

Emacs

Emacs is a text editor that is popular among programmers and developers. It is a powerful, customizable editor that is available on most operating systems, including Linux, macOS, and Windows.

Here are some basic commands that you can use to get started with Emacs:

To open a file with Emacs, type the following command in a terminal:
emacs filename
This will open the file "filename" in the Emacs editor.

To enter text in Emacs, simply start typing. Text will appear at the cursor location.

To save changes to a file, press the Ctrl and X keys together, followed by the Ctrl and S keys. This will save the changes to the file.

To exit Emacs, press the Ctrl and X keys together, followed by the Ctrl and C keys. If there are unsaved changes, Emacs will prompt you to save them before exiting.

To copy text in Emacs, use the Alt and W keys together to mark the beginning of the text you want to copy, then move the cursor to the end of the text you want to copy. Press the Alt and W keys together to copy the text to the clipboard. Move the cursor to the location where you want to paste the text, and press the Ctrl and Y keys together to paste the text.

To search for text in Emacs, press the Ctrl and S keys together. This will bring up the search prompt. Type in the text you want to search for and press "Enter". Emacs will search the file for the text and highlight the first occurrence.

To navigate through a file in Emacs, use the arrow keys to move the cursor up, down, left, or right. Use the PgUp and PgDn keys to move the cursor up or down one page at a time.

Emacs also has a wide range of features and customization options, making it a powerful tool for developers. Some popular features include syntax highlighting, code completion, and version control integration.

To learn more about Emacs and its advanced features, you can check out the official documentation and online tutorials.

Set $EDITOR

In Linux and other Unix-like operating systems, the EDITOR environment variable is used to specify the default text editor that should be used when opening and editing files from the command line.

The set EDITOR=nano command is used to set the EDITOR environment variable to the nano text editor. This means that any command or program that requires a text editor to be opened, such as git commit, will now use nano as the default editor instead of the previously set default.

The nano editor is a simple, easy-to-use text editor that is designed to be user-friendly and intuitive, making it a good choice for beginners who are new to Linux.

Setting the EDITOR environment variable to nano can be useful for users who prefer to use nano as their default text editor, or for users who are not familiar with other text editors like vi or emacs.

To make the EDITOR environment variable persist across terminal sessions, you can add the set EDITOR=nano command to your shell startup file, such as .bashrc or .zshrc, depending on which shell you are using.

To see if EDITOR as already be assigned:
echo $EDITOR

To set environment variable:
set EDITOR=nano

To unset use:
unset EDITOR