Specifically, it refers to the kernel of Linux (the core program of the system), and its kernel copyright belongs to Linus Torvalds, which is distributed under the GPL(GNU General Public License) copyright agreement. Anyone can copy, modify, distribute and sell it freely, but there can be no restrictions when distributing it, and all the original codes must be made public, so anyone can.

For Linux users and system administrators, Linux refers to a complete operating system including Linux kernel, utilities and application software. Linux application software is developed by Free Software Foundation (FSF). Many enthusiastic programmers all over the world have developed or transplanted many applications for Linux, including X-Windows, Emacs, TCP/IP networks (including SLIP/PPP/ISDN) and so on. Now Linux (including kernel and a large number of applications) has reached 200M, and the scale will be even larger after full installation (about 500M).

Essentially, Linux is a Unix "clone" or Unix-style operating system, which is compatible with most Unix standards (such as IEEE POSIX, System V, BSD) at the original code level, and it follows POSIX specification. For example, for System V, the program source code on it can be run after recompiling under Linux, while for BSD Unix, its executable file can be run directly under Linux environment.

The logo of Linux is a lovely penguin. As for why he chose penguins, Linus said: Everyone else has used them. Penguins are cute, aren't they? ! The author of Linux only releases one kernel, and some companies or organizations organize the kernel, source code and related applications to the distributor, so different Linux distributions are produced, such as RedHat, SlackWare, S.u.S.e, Debian and so on.

2. What is the development history of 2.Linux?

The history of Linux can be traced back to 1990. Linus torvalds is a student at the University of Helsinki in Finland. At first, he wrote a program in assembly language to handle multi-task switching in 80386 protection mode. Later, inspired by Minix (a small Unix for operating system teaching), I vowed to write a better Minix than Minix. So I started writing some hardware device drivers and a small file system. ................................................................................................................................ ................................... released version 0.0.2 of Linux on June 5th 199 1, 10, which can already run bash (software for users to communicate with the operating system kernel) and gcc(GNU C compiler).

Linus decided to distribute Linux for free from the beginning, including the source code. He published the source code online, which immediately attracted the attention of fans. They also joined the kernel development of Linux through the Internet. With the participation of a large number of high-level programmers, Linux has developed rapidly. By the end of 1993, Linux 1.0 was finally born. Linux 1.0 is already a fully functional operating system, its kernel is compact and efficient, and it can give full play to the performance of hardware, and it also performs very well on the 80386 computer with 4M memory.

Many people have a misunderstanding about Linux, that is, they always associate Linux with low-end hardware platforms. In fact, from the beginning of 2. 1.xx series kernel, Linux began to take the high-end road. After the version of 1.3, it began to be ported to other hardware platforms, including the so-called fastest CPU——Digital Alpha (the highest frequency at present). At present, Linux can give full play to the performance of hardware.

Linux joins GNU and follows the Public Copyright License (GPL). Because vendors are not excluded from further developing free software or commercial software on Linux, Linux has made a new leap, and many Linux distributions have appeared, such as Slackware, Redhat, Suse, TurboLinux, OpenLinux and so on, and they are still increasing. There are also some companies that develop commercial software on Linux or transplant software from other Unix platforms to Linux. Now many IT giants such as IBM, Intel, Oracle, Infomix, Sysbase, Corel, Netscape, CA, Novell, etc. Support for Linux has been announced! The participation of merchants makes up for the deficiency and obstacles of pure free software, and Linux is rapidly popularized.

3. Why use Linux?

Using Linux allows you to get the performance of high-end systems on a relatively low-cost Intel X86 hardware platform. Many users use benchmarks on X86 machines running Linux and find that the performance is comparable to that of Sun and Digital. In fact, not only many enthusiasts and programmers are using Linux, but also many business users, such as Internet service providers (ISP), are using Linux as a server to replace expensive workstations. The highest record of system stability of these servers is that they have not encountered system crash after running for 600 days!

★ If you can't stand the frequent crashes of Windows and want to change the system platform, then choose Linux. You will be surprised to find that Linux is quite stable and has very good performance.

★ If you want to learn operating systems, such as Unix, you can start with Linux, because people who are crazy about Linux make rapid progress in learning UNIX. Linux is an open source operating system, which follows the Public Copyright License (GPL). It is also very promising, and it is completely free, so you don't have to spend money to buy software licenses again and again.

★ If you are an IT company and Linux is so popular, the potential business opportunities are immeasurable. Study it as soon as possible in order to seize the commanding heights of future development.

★ Linux is very suitable for developing Internet/Intranet. With its open source code, you can develop WEB servers, routers, embedded systems, network computers, personal digital assistants and so on. Oracle, Infomix, Sybase and IBM all support Linux, and it is also good to use it as a database platform. Using Linux can greatly reduce the total development cost.

★ Open source Linux gives you complete control over the system. Open source allows you to add or delete certain functions according to your own needs, build your own operating system at will, and develop an operating system with independent copyright. Linux is one way.

4. What can 4.Linux do?

Linux now surpasses commercial Unix systems in many ways. It supports multi-user, multi-process, multi-thread, good real-time, powerful and stable, and can run on Intel processor, DEC Alphas, Motorola M68k processor, Sun Sparc, PowerPC, MIPS and other platforms. It can run on most hardware platforms at present. Like modern Unix operating system, it also has virtual memory, * * * shared library, command loading, copy-execute-write operation between execution codes, proper memory management and TCP/IP network.

The network function of Linux is very powerful. For example, you can install Linux through FTP and NFS and use it as a WEB server, gateway, etc. With the development of Linux, its derivative applications may be hard for Linus to think of. The biggest single application of Linux is Internet and intranet server, covering specific applications from firewall to Web server. According to analysts' estimation, Linux has become the second largest general operating system on the Internet. Other applications of Linux are "everything from print server to FTP server to data collection". At present, Apache Web server, which is widely used on the Internet, has also become a part of various standard Linux diffusion versions.

Even as a desktop operating system, its performance is better than Unix, which many users are very familiar with. It is no problem for a Linux server to support 100 to 300 users, and it is even easier for a Linux print server to support 200 to 300 network printers. And don't care much about the speed of CPU, and can maximize the performance of each processor. For Linux, the limiting factor that affects the system performance improvement is mainly the performance of its bus and disk I/O.

In addition, LINUX is very different from ordinary software, because it belongs to free software, so you can share Linux with your friends and copy it at will.

5. What is a Linux distribution? What Linux versions are there?

Manufacturers like RedHat generally integrate the Linux kernel and peripheral programs, and then publish their own complete Linux system based on the Linux kernel: usually including a C language and C++ compiler, Perl script interpreter, Shell shell, graphical user interface X window system, X Server and many applications. This complete Linux system is called Linux distribution.

At present, the most widely used Linux distribution is RedHat Linux of Red Hat Company. Now Netscape, Intel and other big companies support it, and the prospects are promising. According to the general view, Red Hat is also the easiest Linux distribution to use. SLackware, which was widely used in the past, is still used by many people. Slackware is a little more complicated than RedHat, which mainly refers to software installation: because RedHat uses rpm packaging system, installing new software is as simple as a line of commands, and Slackware often needs to be recompiled from the source code, which is a little troublesome. SuSE also uses an rpm-based packaging system. What makes SuSE special is that it supports X window system very well. Debian is completely developed by volunteers, based on its own Deb format packaging system, but rpm software packages can also be installed.

6. What's the difference between the kernel version and the distribution version of 6.Linux?

Linux version refers to its kernel version, and Linus and others constantly introduce new kernels, which are widely used in 1.2.8, 1.2. 13, 2.0 and 2.2.x, and the corresponding utilities and application software are mostly GNU or free software.

Beginners often confuse kernel and distribution. For the kernel version, the serial number of the current version is about 2.4.0 (even number as the second serial number means that this is a stable version that can be used, such as 2.2.30, odd number as the second, and generally something new will be added, which is not necessarily stable, such as 2.1.37); Compared with the kernel version, the release version varies according to different types, including Slackware Linux from 1.0.4 to the latest 4.0, the latest version of RedHat is 7. 1, and Debian is 2.2.x

The development of Linux kernel is independent of the development of distribution. For example, Slackware Linux usually includes kernel source code and kernel images of many different hardware devices. The most important thing for ordinary users is to update the system kernel technology: first get the latest version (and make sure it is a stable version) of the kernel source code, then replace the old version of the source code that comes with Slackware Linux, recompile it into kernel binary, and update the old and new, so that the system kernel can be updated without reinstalling the system.

7. What Linux distributions are available on Intel platforms?

There are mainly Red Hat, Slackware, Debian, SuSE, OpenLinux and TurboLinux.

(1) red hat

Known for its simple installation, beginners rarely encounter setbacks when installing this version. If you are familiar with the installation of Win9x, the installation of Red Hat Linux will not be difficult for you.

Another advantage of Red Hat is its RPM (Red Hat Package Manager); When installing software in the past, the biggest headache for users was to create a new directory before unpacking the software, and then move the software in and decompress it. After decompression, some parts may need to be moved to another directory. When there are many projects to be moved, it is a chore to do these jobs. In view of this, the RPM Package Manager can arrange all the paths to be installed. When the user unzips the file with ".". Rpm "extension, they will first check the path file set when packaging the file, and then unpack the file according to the settings in the file and send it to the right place. Not only that, it will also make an installation record. When the user wants to delete any rpm file, the system will install the file in reverse according to the installation record. This is absolutely accurate and will not delete things that should not be deleted like Windows.

Red Hat Linux can be said to be a very successful product. Red Hat Company has an "official version" for users to buy, and also provides a free FTP site for the public to download directly. The difference between the official version and the free download version is that the official version provides more commercial software and beautifully printed instructions.

(2) Casual clothes

This is an old school. Almost everyone who played Linux a few years ago used this system. It is completely possible to "hand-build" the characteristics of personal needs, so that many players who are already experts still remember it. Slackware is widely used in China, and may be used as a server with better performance. In the latest version 4.0, the installation process has been improved a lot. You can try it if you want to "completely control" the situation.

(3)Debian

You usually see the word GNU Linux after the word Debian. This school is currently recognized as the most rigorous structure and the most orderly organizational development. It also has a package management system called "dpk ”( Debian Package), which does the same thing as Red Hat's" rpm "and makes the overall file management more convenient. Debian's original program code is open in the form of GNU, so it completely conforms to the spirit of open source code, unlike other Linux, which keeps some program codes more or less closed (Red Hat didn't open until version 6.0). The current version is 2. 1, and some programmers have transplanted Debian to other platforms, so it can also be seen on other platforms.

(4)SuSE

This is a very popular version in Europe. It cooperates with XFree86 to develop X Server on x86. SuSE can choose to display German or English when installing. It also has its own set of setup programs called "SaX", which can make it easier for users to set up. Its installation kit also adopts RPM mode, so it is very convenient to install, upgrade and remove programs. The current version is 6. 1.

(5) Open Linux

This is a version released by Caldera, which is not a very "open" version. You can download its Lite version online, but the official version costs money, because there are many commercial software in the whole package, so there is no online download service.

(6)TurboLinux

The suite developed by Pacific HiTech has a place in the Japanese market, and the installation and interface are all in Japanese. In China, it cooperated with Tsinghua University and research institutions to develop the Chinese version, which caused a Linux trend in China. At present, the simplified version of 3.0.2 and the English version of 3.6 have been released.

8. What Linux distributions are there on the 8.Mac platform?

Mainly MKLinux, Red Hat, LinuxPPC, Turbo Linux, Yellow Dog Linux, etc. Except MKLinux is the official version of Apple, others are "people in the wild"; However, everyone unanimously adopted the source code packaging method developed by RedHat, plus some of their own suites, and then launched their own version; In other words, everyone's installation method is similar, which is good for users and can save a lot of exploration time.

(1) red hat

See the introduction above.

(2)MKLinux

MKLinux is a version developed by Apple Computer Company, which can be said to be an "old brand". The current version is DR3.

(3)LinuxPPC

The current version is 5.0, with Linux2.2 kernel version 2.2 and Glibc version 2.1; This version supports USB and some new devices, and can be installed on the new Power Mac G3 model. The execution efficiency of LinuxPPC is better than MKLinux. Compared with MKLinux, LinuxPPC can only be used on PCI interface Power Mac, while MKLinux can be used on all models. These two systems are too similar, except for different models and different execution efficiency. Other parts are almost the same, and all executable software is the same.

(4)Turbo Linux

The version of Turbo Linux that can be seen on Mac is version 2. 1 A selection window will appear during installation, allowing users to choose to install MKLinux or LinuxPPC during installation, and then start installing the system. So this version is only different in installation process, and everything else is similar. The Mac version of Turbo Linux has no China culture, and its development speed is much slower than that of PC version. It is estimated that the Mac version has been put on hold temporarily, and Pacific Hi-Tech is fully developing the PC version.

(5) Yellow Dog Linux

It is recommended to install on Mac, iMac, blue and white G3 power Mac series machines. It has two versions, namely the server version named Champion and the version named Black Lab. Champion is a version installed by ordinary users, while Black Lab has the ability of "parallel computing": users can install the system on multiple Macs, and then let all Macs "handle things together", so the processing speed will be very fast. The company developing Yellow Dog Linux focuses on the platform of PowerPC Mac, and there is no version of Yellow Dog Linux on Intel platform at present.

9.RedHat, Slackware and Debian, who will choose?

There are many versions of Linux on the Internet, and even more versions of CDs. RedHat Linux, Slackware Linux and Debian Linux are the three most famous versions.

For beginners of Linux, RedHat Linux is definitely the best choice. Its perfect system configuration, rich pre-installed application software and powerful system management program enable users to obtain a perfect Linux environment in relatively little time and energy, and its unique RPM wrapper program enables users to upgrade the whole system without reinstalling the Linux system. However, its directory structure is complex and the system configuration files are messy, which is not a good choice for advanced users. Slackware is slightly better in this respect.

Compared with Debian, Slackware does not recommend Debian, because in terms of software version, Debian is very different from Slackware with faster update speed.

Therefore, it is suggested that novices choose RedHat Linux, while Slackware seems to be more suitable for advanced users.

10. What Chinese Linux distributions are there at present?

At present, the Chinese Linux distribution versions mainly include: REDHAT Linux6. 1, Red Flag Linux, Blue Point Linux, TurboLinux Chinese version (GB) and Xteam Linux (GB), one of the Tengtu Linux Storm series.

1 1, how to get Linux?

The source code of Linux is open, and all versions of Linux, including the source code and execution files from the kernel to many applications, can be downloaded from the Internet for free. You can also get Linux system by purchasing and distributing CD or D CD. Unlike ordinary software, you can legally share a Linux CD with your friends. Obviously, the price of a Linux CD is not very high. Linux has many distributions and vendors.

12, what are the famous websites and newsgroups in Linux?

Famous websites and Linux online have a lot of news, new software, documents, links and other information about Linux.

Comp.os.linux.announce is a famous linux news group, where you can find many questions and answers about Linux. The following newsgroups in comp.os.linux.* are also worth seeing:

comp.os.linux.setup

Component operating system linux hardware

Comp.os.linux.network

comp.os.linux.x

comp.os.linux.development.apps

comp . OS . Linux . development . system

comp . OS . Linux . advocate

comp.os.linux.misc

If you are slow to access comp.os.linux.*, you can also visit local newsgroups, for example, the newsgroup of China comp.os.linux.* is cn.comp.os.linux

13. How many users can a Linux server support at the same time? How many users can wait at the same time?

There is no limit to the number of users. If only as a file server, there is basically no waiting time. Network bandwidth is a limitation. If you use 100base-Tx, it should feel similar to your local disk.

14, what kind of PC can run Linux?

Linux supports Intel's X86, PIII and other CPUs, and also supports multi-processor systems based on INTEL MP (now it can also run on machines equipped with Sparc, Alpha, PowerPC and other CPUs, and even has been transplanted to Nintendo 64, a game console in the entertainment industry, becoming a simple operating system similar to WindowsCE), which requires at least 4M memory and a single floppy drive. The bus of the PC can be traditional ISA bus, EISA, VESA Local, MCA (all buses of IBM) or Intel PCI. It supports most ESDI, IDE and ATA33/66/ 100 hard disks.

Linux can run on DEC's Alpha computer, Sun's Sparc computer, or Intel's 386+ computer. The source code can be directly compiled, installed and run on various Linux platforms without modification.

The minimum configuration for Linux installation is:

CPU above 80386

Memory exceeds 4M.

Hard disk above 80M

Linux can't run on a machine with 80286 CPU, nor can a machine with less than 4MB of memory. If the memory is less than 4MB, it cannot be installed. If you want to run X Window, the minimum requirement is 8MB. If you use Linux as a server, you must have at least 16MB of memory, and 64M of memory is needed to run software such as Netscape. As for the hard disk, it can be from zero to several GB, and it is best to have more than 500MB of space.

15, what hardware can Linux support?

Linux supports most hardware devices in UNIX systems, including almost all types of graphics cards and monitors, all kinds of mice, almost all types of SCSI devices, most IDE-connected hardware, all SCSI tape drives and QIC-02 tape drives, SCSI CDROM drives, some EIDE(ATAPI) CDROM drives, all SCSI-connected external drives and parallel drives.

The CPU supported by Linux includes: x86 series CPU produced by Intel/AMD/Cyrix.

386SX/DX/SL/DXL/SLC，

486SX/DX/SL/SX2/DX2/DX4，

Pentium.

pentium mmx

Pentium Pro

K6, M2, K7, Cyrix 6x86, etc.

Because the Linux kernel supports analog FPU, even if there is no FPU coprocessor, Linux will support it, but the system speed will decrease, especially when compiling and graphics processing, but now Pentium series CPU has become the mainstream, and this problem does not exist.

In addition, the kernel after Linux2.0 supports multiple CPUs (SMP). No matter which distribution version, as long as the kernel after 2.0 is adopted, multiple CPUs are supported.

The method is: before compiling the kernel, change SMP= 1 at the beginning of /usr/src/linux/Makefile to SMP = n, where n is your CPU number, and then do dep to make it clean; Production and installation; Making module; After make modules_install started, it succeeded!

16. What software is available on Linux? How to run DOS and Windows programs under Linux? Can I run office2000 on it?

Linux has a C program compiler GCC, editing software Emacs, graphical interface X-windows, all standard UNIX system utilities), TCP/IP network (including SLIP/PPP) and hundreds of developed or transplanted applications.

There is a Dos simulator called dosemu in Linux, which can simulate DOS and run some DOS applications. To be precise, dosemu is not a Dos simulator. It provides a virtual x86 machine running dos, which can run Dos6.22 and pure Dos7. It also provides support for VCPI and DMPI. Both Win98 and 386 enhanced modes in standard mode can run under dosemu, but the configuration is quite difficult, the performance is not good, and it is not stable enough.

Linux can also run some Windows programs, and the development of this simulator has made progress. IBCS2 (Intel Binary Compatibility Standard) simulation code supporting SVR4 ELF and SVR3.2cofff can be included in the Linux kernel as a compilation item. In addition, some companies provide some commercial software (paid and copyrighted), such as Motif, Aplixware, WordPerfect and so on.

Office2000 does not have a Linux version, nor can it run on a Windows emulator. On Linux, you can use Linux office software such as staroffice and applixware office, but they are all commercial software.