What should I do after installing the Linux operating system?

1. Start the system

Generally, LILO is installed on MBR. After the computer is started, the Program on MBR is executed, and a non-pretty figure will appear: A Red Hat image on the left, the operating systems that can be started are listed on the right. You can use the keyboard arrow to switch between them. After installation, the default value is Linux, that is, if you do not choose to start Linux later.

If you want to use Windows by default, you can use vi to modify lilo in the/etc directory after Linux is started. in the conf file, add default = windows, and then execute/sbin/lilo to regenerate LILO.

2. User Logon

Linux is a real multi-user operating system. To use this system, you must first log on to it. After using the system, you must exit. When a user logs on to the system, the user name and password must be entered to enable the system to identify the user.

There are two types of users in Linux:

1) root User: Super-privileged, the system owner. In Linux, there is only one root user, which can perform any operation in the system. The password set during system installation is the password of the root user.

2) common users: In a Linux system, many common users can be created, and corresponding permissions can be assigned to them so that they can use the Linux system with limited permissions.

For more information about user management, see the following section.

User logon can be performed in two steps:

1) enter the user's login name. The system identifies the user based on the login name;

2) enter the user's password. The password is a string selected by the user and is completely confidential to other users. It is the only basis for identifying users when logging on to the system, therefore, every user should protect their own passwords!

At the beginning, the system only had root users, while other users were created by root users. The root user's permissions are too large, so misoperations by the root user may cause great losses. Therefore, it is recommended that the system administrator create a new user for himself and log on as the root user only when system maintenance and management tasks are required.

The following is a logon instance: (the input is in bold)

Red Hat Linux release 7.1 (Seawolf) 　　Kernerl 2.4.2-2 on an i686 　　Home login:root 　　Password:

In the above example, we found that the Password is empty. In fact, it is not a Password, but is not displayed in the Linux system when it is entered. This is used to protect the Password!

If the login succeeds, we will get Shell (Shell is a program used to interact with users, it is like the COMMAND in DOS. COM, but in Linux, there can be a variety of shells to choose from, such as bash, csh, ksh, etc.). If you log on as a root user, the obtained prompt is "#". otherwise it will be "$ ".

Tip: If you set it to a graphical interface at the time of installation, after the system is started, the user logon interface will be graphical, a bit like Windows, and when you enter the correct user name and password, you will directly enter the X Window. This setting can be modified:

In the/etc directory, there is an inittab file with one line of Configuration:

id:3:default

The number 3 indicates that the character terminal is started. If the number is changed to 5, the startup enters the X Window.

3. Change the password

To better protect the security of your account, Linux allows you to use the passwd command to change your password at any time after logon. Password modification experience:

1) enter the original password. If the password is incorrect, the program will be suspended and the password cannot be modified;

2) enter a new password;

3) The system prompts you to repeat the new password. If the two passwords match, the password is modified successfully.

It should be noted that Red Hat Linux 7.1 will refuse to modify the new password if it is too simple to better protect the password. The following is an example of a password change: (the input is in bold)

$ Passwd Changing password for user1 (current) UNIX password :? Enter the original password New UNIX password :? Enter the new password Retype new UNIX password :? Enter the new password Passwd: all authentication tokens updated successfully? Modified successfully!

Note that the entered password is not displayed here.

If the password is changed by the root user, you do not need to enter the old password! That is, it can modify the password of any user.

4. log out

Whether you are a root user or a common user, you can log out by simply executing the exit command.

5. Disable the machine.

In Linux, normal users do not have the right to shut down the system! Only the root user can disable it. Of course, if you press the power-off button, do not repeat it. We can implement the following methods:

1) Press CTRL + ALT + DEL to restart the system!

2) execute the reboot command, and the system will restart!

3) execute the shutdown-h now command to shut down the computer!

4) run the halt command to shut down the computer.

Do not shut down the system by means of hard shutdown or restart, which will damage the Linux File System!

6. virtual console

Linux is a real multi-user operating system. It can receive remote and local logins from multiple users at the same time, and also allow multiple logins from the same user. Linux provides virtual console access for local users (that is, users who are working in front of computers), allowing users to log on multiple times from different consoles at the same time.

The choice of the virtual console can be achieved by pressing the ALT key plus the F1-F6 six function keys. For example, after a user logs on, press ALT + F2 to see the "login:" prompt, which is actually the second virtual console, then press ALT + F1 to return to the first virtual console.

You can use the virtual console to experience the features of multiple users in Linux. For example, you can switch to another virtual console to start another job when the work on a virtual console has not been completed. For example, when developing software, you can edit the program on one console, compile the program on another console, and view the information on the third console.

File and directory operations

Like other operating systems, user data and programs in Linux are stored as files. Therefore, when using Linux, files and directories are often operated. Now let's take a Window user's standpoint to learn the file and directory operation methods in Linux.

1. File Name and file type

The file name is the identifier of a file. From this perspective, the file name rules are basically the same as those in Windows 9x. It is also composed of letters, numbers, underscores, and dots. The maximum length is 255 characters.

Like Windows 9x, there are common files and directory files in Linux, but the directory files are abbreviated as directories in Windows. In Linux, a special file is a device file. In Linux, every I/O setting is mapped to a file, which can be processed like a common file. This makes operations on files and devices as unified as possible. From the perspective of users, the use of I/O devices is almost the same as that of General files, so that you do not need to know the details of I/O devices.

2. directory structure

Like in Windows, files are organized through directories in Linux. But the difference is that there is only one root directory in Linux, instead of one root directory in Windows. If multiple partitions exist, mount other partitions to the root directory.

We recall that when we used Linux partitioning, we had an option to fill in, that is, Mount Point. We wrote one of them as "/", that is, the root directory (this is opposite to Windows, one is "" and the other is "/", which is a real family ). Others may be/home and/usr.

After installing the system, you will find that/home and/usr are the home and usr directories under the root directory! By the way, the entire partition is used.