Oracle Learning Starter Series III UNIX, Linux history and fundamentals

Oracle Learning Starter Series III UNIX, Linux history and fundamentals

Finally over the previous two, drink a cup of coffee to carry God, we continue to move forward. This time we have to carry out the operating system knowledge, considering the current time of the operating system diversity, variability, and so on, Toad weighed, decided or unix/linux more in line with our reality.

Before you start, you have to ask a few questions:

1, where does Unix come from

2, where does Linux come from

3, Unix/linux what relationship

4, how to start the system

Alas, see these problems toad is a bit old excited, most like chit chat when is the chicken skin garlic hair thing. Let's hurry up ~ ~ No hurry, leave a mailbox first

I e-mail:[email protected]

Public Number: Hoptoad

Welcome to communicate with all

1 Where does Unix come from

I see a lot of small partners are anxious to practice some orders, to understand the implementation of the operating system, or even to look at the operating system source code, in fact, Toad feel this really do not catch the urgent. If the small partners in such a hurry to do this, Toad believes that not long before the small partners will play retreat. Because this insists on not coming down, encountering a big difficulty, it is easy to let people give up, give up on nothing, the former also white learning. Toad felt that any thing the best teacher was interested in, and how to mention small friends interested in it? I think this is the trivial thing, looking at the feathers of the ground we also know that even the Linux,windows,mac OS these cool operating systems, is also a step-by-step molding, is not out of the way it is now, we can build interest on the one hand, on the other hand can build confidence ha.

Let's cut to the chase, where does Unix come from?

Let's go back to 1965 when Bell Labs, GE, and MIT collaborated on a project (we said in the first article that IBM launched the mainframe in 1964), a project that enables multiple tasks on a single machine, simultaneous access by multiple users, At the same time, let all users feel like they are using the machine as a person (our machine actually has this feature, but the most primitive to do this thing is how difficult). The project name is called the Multics operating system.

By the year 1969, but also after 4 years, Bell Labs feel the project progress is too slow, do not do. (Here we have to mention Bell Labs, Bell Labs invented transistors , lasers , solar cells, light-emitting diodes , digital switches , communications satellites , Electronic digital computer, cellular mobile communication equipment , long-distance television transmission, simulation language, sound film , Stereo recording , and Communication network , a total of 6 Nobel Prizes, scientists, like Wei in the three countries, Generals such as clouds, counselors such as rain Ah, Bell Labs really for the United States, for mankind made a great scientific research, to know that our country has no scientific field of the Nobel Prize, the literature Prize of course another calculation

After Bell quit, there was an old programmer named Ken Thompson (the father of Unix) who was free to play the game of Star Trek, Ready go!! The plane takes off, turns left, Starboard fills, brakes, continues to fly .... Boom.. The plane exploded.

Ken Thompson:[email protected]#$%^&*, this reaction machine reacts too slowly ~ ~ ~

So Thompson found an idle machine PDP-7 and transplanted the game. So Thompson played games on the PDP-7, and he called Dennis Ritchie (the father of C) to play together, this PDP-7 also supports up to 2 people. A colleague Brian Wilson Kernighan (Unix,c) came to say that you are too simple, should be "uniplexed information and Computing Service", abbreviated as "UNICs", and later, We call it "UNIX" when we take it as a homophonic. 1970 can be called the "Unix of the Same".

In 1971, Thompson asked for a better game, applied for a pdp-11/24 machine, they have been playing the game, and now on the machine also implemented a simple System (Unix first edition). By the year 73, new machines came out, and Thompson and Ritchie felt that each time with the assembly was too tired, said the same ah, 12 months a year, he had two transplants for 10 months, playing games on the remaining 2 months, and the next year the new machine came out.

Situation, they decided to use the high-level language to achieve, the idea in that era is indeed a great ah, no wonder is the master. They failed with Fortran, and then use bcpl language, on this basis formed a B language (Unix second Edition), and then Ritchie think this is still not satisfied, and then improved the B language, there is today's C language.

Then he and two together the original compiled code with C rewrite, forming a third edition. So Unix and C are perfectly combined.

Two good base friends because of playing games (cough), through their own efforts to succeed in the history of the It has been a lot of strokes, how to zipping, erase their role, the current game of credit is in the great.

The company felt that no Satan, is not two of the code of the farm to engage in what software, free of charge to the university teachers to play, this noisy, to the late 70, the company found that the business opportunities, and began to protect Unix, so that it became a trade secret. By 1979, UNIX version V7 stopped using UNIX source code.

By the year 80, there have been two branches, one is the authentic version of Bell Labs ' own, one is Berkeley's Bsdunix (not in the past few years open the source, the university teachers are not vegetarian AH). In this way, a Unix war broke out, with various systems appearing, Hp-ux,sun Solaris, IBM's AIX, Bell's own system V, and so on. I just want to say: I go to AH ~ ~ ~. is similar to our spring and autumn Warring States period of contention,

To this end in 1984, the UNIX user association came out and said, "What do you call us to play?" So many systems, different "

Later, the IEEE attack specified the POSIX standard, which defined a language interface that was compatible between the UNIX operating system and the application through a minimal set of features. POSIX is an easy-to-remember name proposed by Richardstallman (the GNU founder, Danale, who came to Hangzhou) at the request of the IEEE, meaning Portable OPerating system Interface (Portable OS interface) , and X indicates the inheritance of its API.

Kenthompson and Dennismacalistair Ritchie the same as the 1983 Turing Award winner.

Unix sources are clear.

Summary: Two a job, love to play the game of yards, during the work of a small software to support their own game, the results play big. In the words of our Chinese people: The weather, geography, people and three elements complete AH ~

Here is a deep tribute to Dennis Macalistair Ritchie,ken Thompson!

Ritchie was kicking on October 12, 2011.

2 Where does Linux come from

So let's go ahead and see where Linux comes from.

In 1979, Bell was not in the Open source Unix code, Andrew S. Tanenbaum of the Computer Science department at Vrije University in Amsterdam, Netherlands (tower nanny professor, Toad favorite) professor, angry and a blow, own the system called Minux (is min unix meaning), A total of 1.2W rows. Used for his teaching career, but do not let others add other code, because reported teacher afraid of too much influence students study, how a loving teacher ah.

In Finland , the University of Helsinki students Linus bought a 386 machine, see the MS-DOS system is not happy, and then spend money to buy reported teacher's book, Yo, book also sent CD, Linux hurriedly loaded on Minix play up, The feeling is very refreshing.

Soon found that this minux function is limited ah, after all, is the study version, and the tower teachers do not allow the addition of other functional modules.

(The world environment at that time is described here:

In 1991, the GNU program has released a number of tools, such as GCC

The POSIX standard has also been released, and internet networks are starting to start. ）

Linus thought for a long time, carried out the preparation, found that GNU has a lot of fun tools, and finally decided to make a system like minux. After half a year of efforts to finally complete, so on October 5, 1991, that is, our national day, published in the Comp.os.minix News Group, the election announced the Linux kernel, was called Freax (Monster), the newsgroup administrator found his surname Linus, Let's call it Linux.

In fact at this time the amount of kernel code is very on, and Minux also a little gap, a lot of ideas directly from the Minux system.

By 93, about 100 programmers had joined the kernel to write the changes, and the 0.99 version was about 100,000 rows.

In 94, Linux 1.0 was released, code 170,000 lines, with the GPL protocol.

Red Hat Company was founded in January 1995.

1996, Linux2.0 Core 400,000 lines, support multiple processors, into the practical phase.

Linux into the fast-growing road ...

Until now.

Summary: A college student in the use of any system are not happy with the situation, their own a set, combined with the weather, geography, people and ultimately overturned the entire industry.

Here is a deep tribute to Linus.

3 Linux Basics

Finally, this chapter of the end of the wrangling, began to have some dry goods must. Let's start with a little hand.

3.1 Shell Understanding

What is a shell?

The shell literally means a shell, which is placed in a shell that is wrapped outside the kernel. The kernel is responsible for dealing with computer hardware, the shell is responsible for dealing with users, Shell player users and the role of the kernel middleman.

What if there's no shell?

Then the system will be very difficult to use, any simple operation requires the user's own code to achieve, humanization is really not flattering. So, when we see Unix coming out, there's basically a shell.

In fact, the shell is some kernel-based application.

So what are these applications made of?
OK, let's take a look at this opportunity.

3.2 Common Commands

Here the Toad assumes that we all have their own liux system, should be for after all to learn the database, database software will certainly be based on an operating system

#cd

Commands to switch directories

#date

Show Time and date

#echo

Display text on the screen

#history

Show the commands entered by the user earlier

#pwd

Show Current working directory

#which

View a command version

#whereis

Query the location of the executable file where the program is used

And so on, and so on, is not easy to list all, we remember as the command, you can walk inside and outside the shell, haha

The important thing is to tell you a few magic tricks

#man

If you don't know how to use the CD command,

#mancd

will show you how to use the CD, remember this victory hundred commands.

3.3 VI Editor

VI Editor is the most basic Linux and Unix text editor , just work that will, listen to colleagues said this thing master all use, so I practiced it, 3 years later finally ....

Discover is actually a software well ~ Master with what does not matter, important is what the master uses it to do.

But then again, 工欲善其事, its prerequisite. So we still need to play a good VI, otherwise it is difficult to edit files under Linux.

Specific Toad does not unfold, to do the following points can be

Know how to open a file (such as: VI a.txt)

Know how to switch modes (vi has two modes, command mode and edit mode)

Know how to insert text

First of all, you can practice, as long as 1-2 days can be skilled.

3.4 Directory Introduction

We know that in Windows after the C-drive D disk, in fact, the first a disk, B, that is reserved for floppy disk use, did not think of the elimination so fast, I remember when my elder sister bought the computer has a floppy drive, There are a few floppy 1.44M size, remember I look inside the black magnetic, thief bright, curiosity driven, and then with a screwdriver are removed, and then ... anyway, butt swollen for a few days.

Windows in the open after the C disk is all the system files directory, Linux is actually similar, but the outermost layer of Linux is a directory called Root, with "/" representation.

We'll just remember a few catalogs for the time being.

A "/" root directory, all other directories derived from here, a system on a "/"

A/boot directory, this directory is mounted under the root directory "/", storage is the boot file

A/home directory where all new users are likely to have working directories in that directory, yes, it is possible, because some may not or need not.

3.5 Other common commands

#ssh Secure Shell protocol for remote login

#ftp File Transfer Protocol

Standard protocols and primary ways to #telnet Internet remote login Services

#top System Monitoring Commands

#vmstat process, CPU, memory, and fault pages monitoring commands

Everyone can own Baidu or Google study, or follow up on the further learning is not too late. Because these are not the focus of this study series, this is the end. Next we will learn about Oracle, it is a little excited to think about it.

Oracle Learning Starter Series III UNIX, Linux history and fundamentals