Basic operating system of Linux- Three
Today is going to post the third of this series. I do not know how it’s going. Because there has been no significant discussion – critical criticism etc., so far. Anyway, I want to end this series in front of my main purpose, keeping in mind the new Linux users of the future.
Today we will discuss Linux’s multi-user concept, file system, symlink, file search and more.
Multi-user or multi-user based
Like other server operating systems like Linux and UNIX and more user-oriented operating systems. However, nowadays some of the distro options for selecting single user mode are given at boot time. For example, if a Linux system is set up on the network, multiple users at the same time can use their Windows PCs to launch Telnet sessions at the Linux server. As a result, every user will get their own terminal session, ie each one has its own shell prompt, where you can give any shell command arbitrarily.
Of course, nobody can do this. Only those who have access to the system will be able to access it through Telnet. An account is created on the Linux system by creating a login ID (name or similar) for any user and password. For this reason, after a boot up to a Linux system (or after telnet), you will first get a login prompt. First of all, the operating system will ask who will enter the system. Then it will allow certain permissions to be given to the system, along with those already provided (for example, there are no permissions to change or delete system files in most accounts).
As already mentioned, if the system is logged as a root user, then any file can be accessed, modified or deleted because the root of Linux or UNIX is the power of all power. The root user is ready when the operating system is installed. At the time of installing Debian or Ubuntu, a user has to enter a password for the root user and at that time it is asked whether to create additional user accounts. After installation and you can create additional accounts with the root account. This root account is usually used to install software or programs and to modify the configuration files of the application which is basically a text file that changes with a normal text editor.
Even if you have standalone Linux system, you can use it as a multi-user system. When you first boot the machine with a login prompt, you actually see the first of several terminals sessions. To view the rest, after logging in, press the Alt key on your keyboard and press F2. You will see another login prompt and this is the second terminal session. This way you will get one after the login prompts after pressing F3 to F6. F7 is currently your logged in a graphical interface. If the machine is booted in graphical mode first, press Alt and F7 to bring it back to your graphical mode again. Each terminal session allows you to login in different names. Such terminal sessions are called ‘consoles’ or ‘virtual terminals’. The use of such multiple terminals is quite useful when you work on the configuration level of a specific file or directory. In this type of work, logging as a root in the terminal, you can perform all the permissions set and by logging in as a normal user in another console you can check the settings.
These multiple consoles are not limited to the use of virtual terminals only. If you want to connect a Linux terminal with a dumb terminal, then you can connect with a serial port and unkempt some lines of / etc / inittab file to allow them to access their own terminal sessions. Instead of using dumb terminals, you can also use normal PCs, which will be connected through a serial port of the Linux machine with a program called HyperTerm. Null-modem cable is only required for a PC-to-PC connection. This kind of dubbing terminal can also be used in the case of dumb terminals, which may be based on the interface. Since most PCs have two serial ports, the same Linux system can use at least 3 people together.
Some user accounts are automatically set up / ready to provide specific services. For example, if you want to use your Linux system as an FTP server, then there will be a user account named FTP. This FTP account allows anyone who is connected to the server to do all the work.