Linux is an open-source UNIX-like operating system known for its stability, efficiency, and security. In Linux, editing the contents of a file is a very basic operation. This article will introduce how to edit the content of a file in Linux system in detail.
We need to know the file permissions of the Linux system. In Linux, each file has an owner and a group to which it belongs, as well as access rights for other users. These permissions include Read (R), Write (W), and Execute (X). To keep our files safe, we can set different permissions. For example, we can set a file so that only the owner can read and write executions, and other users can only read it.
To edit the content of a file on a Linux system, we usually use a text editor. There are many text editors to choose from in Linux, such as vi, emacs, nano, etc. Let's take the most commonly used text editor VI as an example to show how to edit a file.
1.Open the file.
To edit a file, you first need to open it. Enter the following command in the terminal:
vi filename
where filename is the name of the file to be edited. This will open the vi editor and display the file contents in the terminal.
2.Enter the insertion mode.
In the VI editor, there are three modes: normal mode, insert mode, and command mode. When we first opened the file, we were in normal mode. To edit the contents of the file, we need to enter the insert mode. Press the I key and the VI editor will enter insert mode, where you can enter text to edit the file.
3.Edit the contents of the file.
In insert mode, we can edit the content of the file. For example, we can delete a piece of text, add a piece of text, or modify a word. When you're done editing, press the Esc key to return to normal mode.
4.Save the file.
After editing the content of the file, we need to save the file. In normal mode, enter the following command:
:w filename
where filename is the name of the file to be saved. This will save the changes we've made to the file. If we want to save as a new file, we can use the following command:
:w newfilename
where newfilename is the new filename. This will create a new file and save the changes we made to the file to the new file.
5.Exit the vi editor.
After saving the file, we need to exit the vi editor. In normal mode, enter the following command:
:q
This will directly exit the vi editor and discard the modifications we made to the file. If we want to save the changes and exit the vi editor, we can enter the following command after saving the file:
:wq
This will save the modifications and exit the vi editor. In addition, we can also exit the vi editor with the following command:
:x
This will save the modifications and exit the vi editor. It should be noted that if you make changes to the file but exit the vi editor without saving, the next time we open the file again, we will be prompted whether to restore the unsaved modifications. If you don't want to see this prompt, you can use the following command when opening the file:
vi -r filename
where filename is the name of the file to be edited. This will overwrite the unsaved modifications and reload the file contents.