1th Shusaku A Brief introduction

1. The composition and function of modern computers

Modern computers are based on the von Neumann system, which consists of an operator, a controller, a memory, an input device and an output device. Among them, the arithmetic is mainly responsible for the operation of the data, the controller is the control center of the whole calculator system, to ensure the coordination between the various components of the system; memory is used to store data; The input device is used to get user input and convert it to a binary that the computer can understand. The output device is a computer program or other computer processing of data in the human can understand the pieces, text and other forms presented.

Major releases of 2.Linux, and links and differences between different distributions

Based on Linux kernel and related technologies, it is currently divided into three major releases, Slackware, Debian and Redhat.

Among them, based on Slackware the main derivative of SuSE (Enterprise Edition, widely popular in Europe), openSUSE (community version);

Based on the Debian derivative of the two release version represented by Ubuntu, but also based on Ubuntu has its three releases, such as the Ubuntu Mint,kubuntu,ekubuntu and other derivative versions, while the Debian system (and its derivative system) is the only non-commercialized distribution series in the current three major distribution releases;

Based on the Redhat branch has Rhel (extremely stable Enterprise version, the release cycle is generally 18 months, with a more conservative release strategy), Fedora (mainly for individual users, which is essentially as the first technical version of Rhel future technology) and CentOS (Community edition, Fully compatible with Rhel format) and other major branch releases;

At the same time, 2 more famous new generation distributions ArchLinux and Gentoo have been produced in recent years.

The philosophical thought of 3.Linux

All documents: Whether the software hardware devices in the Linux system, in the form of files exist and show;

Consists of a number of single-purpose small programs: A program to achieve only one function and the pursuit of perfection, for the complexity of the task, it is composed of a number of small programs;

Try to avoid interacting with users to show scripting goals;

Use plain text files to save configuration information.

4.Linux command usage format and some command usage and examples

Format: command [options] [arguments], from left to right to indicate commands, options, parameters, and 2 are optional.

①ifconfig command: User view current network configuration information

②echo for Echo,-N and-e are used to prevent automatic addition of line breaks and allow the use of escape characters

③tty display the current terminal number

④startx in the character interface, use STARTX to start the graphical interface (provided that the graphical interface has been followed)

The ⑤export is used to specify the environment variable value in the format: Export variable name = value

⑥PWD display the current working path

⑦history view command execution history,-A for adding commands when the current History list, the same-D and-C respectively are used to delete a history execution command and empty the entire command history;!! Displays the previous command,!number and!string execute the specified or most recent string command

⑧shutdown for shutdown, followed by-R for restart,-h for shutdown,-C to cancel the current pre-shutdown (restart) operation, and then add the time parameter to specify a period for shutdown (restart) operation

⑨poweroff for shutdown

⑩reboot for restarting your computer

Hwclock does not take any option when the hardware clock is accessed, followed by the option--hctosys can adjust the system clock to match the hardware clock,--SYSTOHC the hardware clock to match the system clock;

Date Displays the current system time without parameters and options, and can be formatted with the corresponding format time display, such as Date +%h-%m-%s, which can be formatted to output the current system clock in seconds

5. Get help for commands on Linux systems, as well as chapter partitions for man documents.

It is divided into three main ways:

①man [Page Number]command is valid for all commands or installed software

②help command is valid for internal commands

③command--help is valid for all commands or installed software

④ installation to the system of the program documentation or the program's official site Doc document

⑤ Search Engine

The man document is divided into the following sections according to different categories of action:

①standard commands (Standard command)

②system calls (System call)

③library functions (library function)

④special Devices (Equipment description)

⑤file formats (file format)

⑥games and Toys (games and entertainment)

⑦miscellaneous (Miscellaneous)

⑧administrative Commands (Administrator command)

The base directory name of the 6.Linux release and its functional provisions

/root directory

/bin storing the necessary commands

/boot storage System startup related files

/dev Store device files

/etc Store the configuration file of the system

Home directory where user data resides in their home directory, and if user Qiu, their home directory is/home/qiu

/lib storing the necessary runtime libraries

/mnt is often used to mount

/proc storing stored process and system Information

/root Root's home directory

/sbin Storage System Management Program

/tmp directory where temporary files are stored and regularly cleaned

/usr command program files, libraries, manuals, and other documentation.

/var contains frequently changing files generated by the system, such as printers, mail, news and other spool directories, log files, formatted hand albums, and data files for some applications, etc.

1th Shusaku A Brief introduction