John:    Hi, Peter. Do you hear? Dennis did 3 millions dollars in only six months. Amazing!

Peter:   Yes. I speak whit Dennis about that.

John:    How is possible? Seems that he install a Web Server to run its products.

Peter:    Yes, and he install Linux!

John:    Linux? What is Linux?

Peter:    A student called Linus Torvalds, working for itself, release an Operating system based on Minix in 1991. Then he ask for help and today the community includes millions of people.

John:    Yes, I hear about but What is Linux?

Peter:    Well, Linux is an Operating System. It includes a complete set of utilities like compilers, filters a graphical enviroment and the most important component: the Torvalds's kernel.

John:    What is a kernel?

Peter:    A kernel is a set of compiled source (objects) that allows to handle the hardware. PC, Macs, Alpha based machines, Sparc ... everything!

John:    Great. How works?. I heard that is free.

Peter:    Yes. Linux is a free operating system. However there are various companies that putting all these parts together: kernel, graphical interfaces, compilers and offer it in a distributions for some dollars.

John:    But, how works the Web server, where I write http://cnn.com, for example ?

Peter:    Well, in this case there are a program called "apache", that is the most used http daemon that allow to visualize Web pages.

John:    Yes. The web pages have an extension, htm or html.

Peter:    In fact. HTML is the Hyper Text Markup Language, and allow to link an image or a page to another and so on, so is possible to browse the Web.

John:    What is the Web?

Peter:    The Web or WorldWide Web, are all the Web servers in the World. Internet is the same definition for the more technical point of view. Internet is the International Network, composed by these machines.

John:    I understand. Is complex install a Web server?

Peter:    Not really. You need a PC Intel o Mac, and a Linux distribution. You need also to contact the phone company and install a High Speed line. The DSL is the latest cheap choice or the classic T1 (1.544 Mbps). There are also a T2 (6.312 Mbps) and T3 (44.736 Mbps). After you have a Speed Line, you can download a Linux ISO Linux image and put on a CD, then install your Web server. With a DSL is possible to download 650 MB in 1 hour.

John:    Really?. I can install a Web Server with Linux without pay nothing.

Peter:   Yes, is correct. However, you need a PC, a High Speed Line and a WebMaster.

John:    Who's a WebMaster?

Peter:    A webmaster is a person that knows how to install a WebServer, knows HTML, PERL and CGI Programming, Javascript, and also MySQL, PHP and other Web programming languages. Dennis, have one or two, I don't remember. There are also pre-installed Linux Web Server, is you want to save time. But, you need to learn Web programming.

John:    What is PERL?

Peter:    PERL is a programming language developed by Larry Wallman to help shell programming. Perl's name came from the acronym Practical Extraction and Report Language. The orginal Perl goal was to substitute sed and awk. Today generally is used to generate dynamic HTML pages in ecommerce. PHP is the new language for this subject. PHP stands for Pre Hypertext processor and was created by Rasmus Lerforf and is very usefull to handle MySQL databases. To support PHP pages is necessary to install the modules in apache. There are also other languages like Python, and other toosl to help WebMasters.

John:    What is MySQL?

Peter:    MySQL is a SQL database that allows to use data easily using SQL commands.

John:     All this matter may be very expensive.

Peter:     Not really. In true all the packages are included in any Linux distribution.

John:    What I need to install an e-commerce Website?

Peter:    Do you need a PC better if faster, a high speed phone line and a Linux distribution. Then you need to learn HTML, PERL, CGI and MySQL minimum. PHP are now covering the last three topics.

John:      Why, when I visit a Website I need to write, "http://", then "www.futuretg.com". What means ?

Peter:    Well. "http://" tells the browser the protocol to be used and "www.futuretg.com" is the name of the remote machine, on the web.

John:     A Protocol? What is a protocol?

Peter:     A protocol is a mode to transmit data. The HTTP standard protocol, Hypertext Transfer Protocol, was written by T. Berners-Lee and other people, in RFC1945, in 1996 in a formal way because Apple introduced these concepts some years before.

John:    Are there other protocols?

Peter:    Of course, there are FTP (File Transfer Protocol), TCP/IP (Transmition Control Protocol/Internet Protocol), the standard Internet protocol also used for Intenal networks.

John:     What about email?. How works that?

Peter:    emails are transported between servers over a TCP/IP network with a protocol called SMTP, Simple Mail Transfer Protocol. This is explained in the RFC821. Other RFC explain the MIME (Multipurpose Internet Mail Extensions), UUCP Mail Interchange Format Standard and others like the Context-type.

John:    Is really great. Everything is transported by the TCP/IP?

Peter:    Yes. There are also the IP address concept. Generally Web servers have an IP address in dot notation. For example 213.82.126.2 , is an alias for www.futuretg.com. Thus, run "http://www.futuretg.com" and run "http://213.82.126.2" is exactly the same.

John:     How each Web server knows this assignation?

Peter:    They know because there are DNS Servers that translate the information. Each Internet access from home or work needs to access a DNS (Domain Name System) server.

John:    But, if I want to have a website with my company name, i.e: "http://www.mycompany.com/", What I need to do?

Peter:    You need to subscribe at http://www.networksolutions.com/ and try to find if the "company.com" literal address (URL) is available. May be yes or may that some other person take this site name before. You can check if the name is available or the owner at "http://www.networksolutions.com/cgi-bin/whois/whois".

John:    Thanks Peter, your explanation was excellent

Peter.   You welcome. I will visit Dennis to know if he got more money.

...

The previous dialogue explain what is Internet and how important is to know. Now, we will review these concepts from a more detailed point of view. This WebMaster course will teachs you the WebMaster programming techniques as well how works internally.
 

What is Internet?

Internet is the International Network composed by thousands of Web servers connected each other. The next figure show this idea.

Though Internet, users can reach and order software, books and services in any location, not just in the city where they live or born.

Web servers are located in any place.  A Web server is a computer runnig the http protocol, like apache, that allow web servers to answer remote user requests.

For example, when you hit the command: http://www.w3.org/ (http://www.w3.org without the final '/' is not correct) , your computer search for the nameserver listed in "/etc/resolv.conf".  The nameserver (if founded) translate the information "www.w3.org" in 18.29.1.34 (actually, April 2001). Then the http at 18.29.1.34 send HTML pages and images (data) to your system trough your modem (or your Internet connection).

A way to trace this information is running the program: "traceroute".

This is the output:

[root@www /root]# traceroute www.w3.org
traceroute: Warning: www.w3.org has multiple addresses; using 18.29.1.34
traceroute to www.w3.org (18.29.1.34), 30 hops max, 38 byte packets
 1  213.82.126.1 (213.82.126.1)  1.188 ms  1.159 ms  1.137 ms
 2  r-ts1-cesped.interbusiness.it (195.31.13.185)  16.153 ms  13.425 ms  14.673 ms
 3  r-ts2-fa11.interbusiness.it (195.31.14.194)  14.250 ms  13.668 ms  14.229 ms
 4  r-mi102-ts2.interbusiness.it (151.99.98.105)  25.595 ms  28.796 ms  25.574 ms
 5  r-mi99-fa3.interbusiness.it (151.99.75.134)  24.184 ms  23.683 ms  24.935 ms
 6  r-mi97-fa6.interbusiness.it (151.99.75.38)  24.190 ms  27.785 ms  24.227 ms
 7  mi5-tinp-3-it.seabone.net (195.22.196.49)  297.957 ms  299.162 ms  313.480 ms
 8  sl-gw9-nyc-5-1.sprintlink.net (144.232.173.29)  388.040 ms  380.687 ms  388.511 ms
 9  sl-bb21-nyc-6-0.sprintlink.net (144.232.7.97)  383.857 ms  392.977 ms  404.544 ms
10  sl-bb2-nyc-0-0.sprintlink.net (144.232.13.195)  403.953 ms  411.423 ms  403.299 ms
11  144.232.18.30 (144.232.18.30)  416.372 ms  417.526 ms  415.320 ms
12  p1-0.nyc4-nbr3.bbnplanet.net (4.0.5.26)  410.490 ms  428.328 ms  434.251 ms
13  p4-1.bstnma1-ba2.bbnplanet.net (4.24.4.237)  427.643 ms  435.789 ms  439.769 ms
14  p1-0.bstnma1-ba1.bbnplanet.net (4.24.4.193)  434.393 ms  443.494 ms  449.661 ms
15  p2-3.cambridge1-nbr1.bbnplanet.net (4.0.2.166)  451.126 ms p5-1.cambridge1-nbr1.bbnplanet.net (4.0.2.169)
438.301 ms  436.006 ms
16  p1-0-0.cambridge1-br1.bbnplanet.net (4.0.1.22)  434.192 ms  429.376 ms  434.525 ms
17  h3-0.cambridge2-br2.bbnplanet.net (4.0.1.202)  419.899 ms  428.645 ms  413.908 ms
18  ihtfp.mit.edu (192.233.33.3)  405.578 ms  408.364 ms  419.942 ms
19  B24-RTR-FDDI.MIT.EDU (18.168.0.14)  420.011 ms  434.212 ms  435.287 ms
20  RADOLE.LCS.MIT.EDU (18.201.1.3)  431.765 ms  436.812 ms  420.163 ms
21  anacreon.lcs.mit.edu (18.24.10.1)  425.702 ms  434.664 ms  428.333 ms
22  web4.w3.org (18.29.1.34)  430.462 ms  425.444 ms  419.076 ms
[root@www /root]#

Another mode is using the program nslookup

[root@www /root]# nslookup www.w3.org
Server:  dns2.interbusiness.it
Address:  151.99.125.3

Non-authoritative answer:
Name:    www.w3.org
Addresses:  18.29.1.35, 18.29.1.34

[root@www /root]#

If you want to know where is located the (may be multiple: more than one), you need to know "whois". In Internet terms: "whois" is the physical location where the Web Server is installed.

The most easy way is go to http://www.networksolutions.com/cgi-bin/whois/whois and check!

if you are running Linux you simply can run the command from the console:

[root@www /root]# whois w3.org
[whois.crsnic.net]

Whois Server Version 1.3

Domain names in the .com, .net, and .org domains can now be registered
with many different competing registrars. Go to http://www.internic.net
for detailed information.

   Domain Name: W3.ORG
   Registrar: NETWORK SOLUTIONS, INC.
   Whois Server: whois.networksolutions.com
   Referral URL: www.networksolutions.com
   Name Server: DNS.W3.ORG
   Name Server: W3C2.W3.ORG
   Name Server: W3CSUN1.CIS.RL.AC.UK
   Name Server: W3CLA-SUN.SICS.SE
   Updated Date: 23-jun-2000
 

>>> Last update of whois database: Tue, 24 Apr 2001 12:01:43 EDT <<<

The Registry database contains ONLY .COM, .NET, .ORG, .EDU domains and
Registrars.

[root@www /root]#

In 1968, Vinton Cerf and Bob Kahn from DARPA (Defense Advanced Research Project Agency) develop ths TCP/IP protocol. The original idea was "In how many ways is possible to reach the enemy target?". Suppose that you need to conquer a montain or a specific strategic position,  in a war. To plan the attach you need to know in how many ways you can reach this strategic position. This is important not only for the attach but also to close any probably exit door, so the enemy will lose the position.

Internet transform this idea in the most easy way to communicate and to join the world. Reach the remote enemy was transformed by reach the remote server.

You hit for example: http://www.ibm.com. ... your system looks for the name server for example 213.82.126.10. Once located the TCP/IP Protocol runs a procedure to locate the remote server in the most short time. From a mathematical point of point, is similar to the question: " What is the shortest path in this graph". The Graph Theory was created by the mathematician Leonard Euler at the begining of this century.

However, was the DARPA to create, write and develop the protocol that today make possible e-commerce business, send emails to friend or download Graphical Interfaces or entire Operating System at no cost.

To check how TCP/IP works, we can "ping" a remote server:

[root@www /root]# ping www.w3.org
PING www.w3.org (18.29.1.34) from 213.82.126.2 : 56(84) bytes of data.
64 bytes from web4.w3.org (18.29.1.34): icmp_seq=0 ttl=235 time=156.9 ms
64 bytes from web4.w3.org (18.29.1.34): icmp_seq=1 ttl=235 time=150.6 ms
64 bytes from web4.w3.org (18.29.1.34): icmp_seq=2 ttl=235 time=145.3 ms

The "ping" program send "bytes of data" trought the modem (or Internet) line to the remote server. If the remote server is "alive", he reply the same data. The TCP/IP present in the remote system send the data back.

Woriking with Unix systems, this is very easy ... and from long time ago. Non Unix systems like MS Windows or the Mac OS, includes TCP/IP implementations, inside its OS. Also, in this case works fine, but generally is not the "original" or the same. This is another reason because UNIX and particularly Linux offers a better choice for Web Server.

Another more clear mode to test this strategy is running the traceroute program:

We ran here two times the same programs ... and we got two strategies to reach the remote server!
 

This is how Internet works!

The Internet community need to thanks the DARPA project for this invaluable help.
 

Internet services.

The TCP/IP protocol start to be used in companies from 1979 when AT & T start to commercialize its UNIX. Remote printing, telnet, finger, e-mail, gopher services, FTP services start to be used in anyplace but specially in the US.

But the real Internet success happens in 1995, when the most important companies though Netscape Navigator start to browse the Web, send e-mails and read the news in a graphical enviroment and the Apache Group release its Apache (APACI) HTTD protocol, based on the NCSA HTTPd 1.3.

From those days thousands of companies around the world, start to offer Internet Services, and the ISP (Internet Service Provider) become a serious commercial business.

We list here the most common Web or Internet Services:

http, Hypertext Transfer Protocol.

ftp, File Transfer protocol.

telnet, can allow to open a session on the remote machine.

finger, to get important remote information

[root@www /root]# finger @finger.kernel.org
[zeus.kernel.org]

    The latest stable version of the Linux kernel is:     2.4.3
    The latest beta version of the Linux kernel is:       2.3.99-pre9
    The latest prepatch (alpha) version *appears* to be:  2.4.4-pre6

[root@www /root]#

chat, allow to send messages to remote system, to interact with different system at the same time.

SMTP, allow to send and receive electronic mail, e-mail, from any place in seconds.

The news: Discussion groups for about, more than 100,000 topics, from alt.adoption until wales.sport.

Mr. Tim Berners-Lee develop its first web browser and server in 1990. He is the ideator of the HTML Language. Mr. Berners-Lee resume all its efforts in the design of the HTML language in its RFC1945.

Web servers running a HTTPd protocol communicate trought Web browsers like Netscape Communicator or Explorer to "visit" remote Web Servers.

For example using  Netscape 4.72 for Linux, you can ...
 
 

... browse your TV Guide (www.tvguide.com).	Some smart web sites (offers also Tele-Text, like www.rai.it)

Today, using the Web you can obtain any type of information in seconds contact directly the source or the main company, download any type of software ... and practically do anything.

These wonderfull HTML pages are wtitten in HTML Lnaguage. If you wants to check the original HTML pages for these website you can press (Alt+U) using Netscape Communicator (or View -> Page Source)

HTML Language is relative easy to learn and program.

There are a head and a body.

We present here a simple.html file

[root@ftosx1 HTML]# more simple1.html
<!doctype html public "-//w3c//dtd html 4.0 transitional//en">
<html>
<head>
   <meta http-equiv="Content-Type" content="text/html; charset=iso-8859-1">
   <meta name="GENERATOR" content="Mozilla/4.76 [en] (X11; U; Linux 2.2.17 i686) [Netscape]">
</head>
<body>
hello!
</body>
</html>
[root@ftosx1 HTML]#

The "rai.it" Televideo pages use JavaScript language.

All this is possible because the remote server runs Apache and using the HTTP protocol the HTML pages and images are interpreted by your browser.

A simple way to check if you system are running apache is running the following command:

[root@www /root]# ps ax | grep httpd
  792  ?  S    0:20 httpd
31371  ?  S    0:00 grep httpd
30538  ?  S    0:00 httpd
30552  ?  S    0:00 httpd
30618  ?  S    0:01 httpd
30802  ?  S    0:00 httpd
30803  ?  S    0:00 httpd
30804  ?  S    0:00 httpd
30868  ?  S    0:00 httpd
30869  ?  S    0:00 httpd
30870  ?  S    0:00 httpd
30872  ?  S    0:00 httpd
30873  ?  S    0:00 httpd
30874  ?  S    0:01 httpd
31041  ?  S    0:01 httpd
31042  ?  S    0:01 httpd
31043  ?  S    0:01 httpd
31044  ?  S    0:01 httpd
31045  ?  S    0:01 httpd
[root@www /root]#

To know what version your server are running you can run the command:

[root@ftosx1 /root]# httpd -v
Server version: Apache/1.3.17 (Unix)
Server built:   Feb 13 2001 17:09:58
[root@ftosx1 /root]#

Fast Training Linux Course, wants to explain you all the necessary steps to follows to run your own Web servers from scratch, from the Web Server installation, until its programming like the simple HTML, until complex PHP or PERL.
 

FTP Servers.

From different years, in different places in the world Servers offers the possibility to download software.

Storically speaking, FTP Protocol was available from 1971 RFC172, while the "modern" HTTP from 1994 (For a complete search you can visit: http://info.internet.isi.edu:80/7g/in-notes/rfc/files, and search FTP and HTTP).

Therefore Servers (Computers offering services), and in this case FTP Servers become available more than 20 years before the actual Web Servers.

With the Internet boom, in 1995, invaluable programs like Netscape Communicator, offers all the Internet services from the same program. In this case we present a FTP session opened at FTP.KERNEL.ORG

The FTP Protocol (File Transfer Protocol) goal is to offers a stable protocol to download files. While also with other protocols like HTTP, is possible to download files, the FTP is the storical as well as better choice, stable from 20 years.
 

Finding software with Archie.

Before that modern browsers offers the possibility to download files with the FTP protocol, the "archie" and its graphical version "xarchie" were the choice to locate files from the "FTP Web"

This protocol is still present in about twenty Archie Websites around the World.

FTOSX 2002, and also SuSE Linux support this service. In few words archie is: "archie - An Electronic Directory Service for the Internet".

Like, FTP or Telnet, archie. We open a query looking for a remote software, for example: "elm".

[root@ftosx1 root]# archie -h sunsite.cnlab-switch.ch elm

Host sunsite.cnlab-switch.ch

    Location: /mirror/FreeBSD/branches/-current/ports/korean
      DIRECTORY drwxr-xr-x       4096  Oct  9 2000  elm
    Location: /mirror/FreeBSD/branches/-current/ports/mail
      DIRECTORY drwxr-xr-x       4096  Jul 25 00:32  elm
    Location: /mirror/SuSE/suse/axp/7.1/suse/contents
           FILE -rw-r--r--       1616  Aug 15 11:43  elm
    Location: /mirror/SuSE/suse/ppc/7.1/suse/contents
           FILE -rw-r--r--       1622  May 15 2001  elm
    Location: /mirror/aix
      DIRECTORY drwxr-xr-x        512  Feb 19 1999  elm
    Location: /mirror/slackware/alpha/slackware-current/source/n
      DIRECTORY drwxr-xr-x        512  May 17 2001  elm
    Location: /mirror/slackware/slackware-8.0/source/n
      DIRECTORY drwxr-xr-x        512  Apr 18 2000  elm

Host ftp.tik.ee.ethz.ch

    Location: /pub/packages/pgp/utils
      DIRECTORY drwxr-xr-x        512  Sep 13 1996  elm
[root@ftosx1 root]#

The FTOSX 2002 version uses the archie search engine: sunsite.cnlab-switch.ch, as default, and is more quick.

[root@ftosx1 root]# archie xgo
No matches.
[root@ftosx1 root]# archie xterm

Host sunsite.cnlab-switch.ch

    Location: /mirror/LinuxGazette/www_root/issue27
           FILE -rw-rw-r--        901  Mar 26 1998  xterm
    Location: /mirror/SuSE/suse/ppc/7.1/suse/inst-sys/usr/share/terminfo/x
           FILE -rw-r--r--       1914  May 13 2001  xterm
    Location: /mirror/X11/R6.4/xc/doc/hardcopy
      DIRECTORY drwxr-xr-x        512  May  5 2001  xterm
    Location: /mirror/X11/R6.4/xc/doc/specs
      DIRECTORY drwxr-xr-x        512  Aug 11 00:32  xterm
    Location: /mirror/X11/R6.4/xc/programs
      DIRECTORY drwxr-xr-x       1024  Aug 11 00:32  xterm
    Location: /mirror/X11/R6.6/xc/doc/hardcopy
      DIRECTORY drwxr-xr-x        512  May 11 2001  xterm
    Location: /mirror/X11/R6.6/xc/doc/specs
      DIRECTORY drwxr-xr-x        512  May 11 2001  xterm
    Location: /mirror/X11/R6.6/xc/programs
      DIRECTORY drwxr-xr-x       1024  May 11 2001  xterm
[root@ftosx1 root]#
 

Basically, "archie" service is usefull to locate archives in FTP serves.

We present here "karchie" (a KDE version for xarchie).

Electronic mail (e-mail).

Probably the most important Internet help to worlwide communications is the e-mail. With the e-mail that travels under TCP/IP, using the SMTP, Simple Mail Transfer Protocol, RFC788 (1981), people around the world can
send and receive messages and files (MS Word Documents, Images, etc) ... in seconds.

On Linux all the emails are handled by sendmail program.

A simple program to use sendmail may be:
 

/usr/sbin/sendmail -v gorlando@futuretg.com < news
 

Once again, Netscape offers to us the possibility to handle e-mails ... any number. We can save also 5,000 or more e-mails without problems. Netscape Communicator for example includes an "Inbox" and "Sent" directory where saves your messages.
 
 

We will cover Netscape Communicator in Chapter 3: W3.

The common RFC references regards the documents or articles written by the Internet pioneers. RFC stand for Request for Comment. Generally we present here the first document. Like any other document or important development there are enhancements and updates.

Fast Training Linux Course includes all the RFC from its first release. You can check directly from the Web for example from: http://info.internet.isi.edu:80/7g/in-notes/rfc/files
 

Discussion groups: news.

The discussion groups are similar to the open forum what available from the Web. For example, in 1989, the classical program to read the news was: "rn" (then rnews).

Netscape Communicator offers to us the possibility to browse these discussion or "news groups" from its Communicator.

There are more than, 11,000 groups and for example the "alt" group include 1427 groups. When you reach a group you can subscribe (for free, of course) to a specific group and ger its "news". You can read one-by-one, read and answer if you prefer.

Generally no other product offers all this possibilities at the same time. For example, MS Explorer does not offer this possibility.
 

Chatting with chat.

In Nowadays is also possible chat (speaking or send comments to a remote user).

Linux offers "xchat" for example:
 
 

However, ICQ is also very popular and also the VideoConference is really the maximum advatange that Internet offers today.

Another languages had been developed in the past years. VRML for example offers the possibility to browse remote websites with VRML browsers feeling like in "Alice in Wonderland".

E-Commerce Website elements.

To finish this introductive chapter we will resume the points that we will cover in this WebMaster training course.

The final goal of this course is to teach you everything about a WebMaster ... from the installation of the Linux server ... its setup: DNS, SENDMAIL ... until programming Techniques.

We resume here the topics:
 
 

	Install the Linux Operating System - W15
	Apache Test - W16
	Create users accounts - W15
	Design your Web site  in accord with W3C specific - W5
	Setup a gateway if necessary - W15
	Setup the DNS - W17
	Update the sendmail configuration - W18
	Create the E-commerce customer DataBase -  W13
	Install PERL and PERL modules if necessary - W12
	Install PHP - W14
	Secure access with Mod+SSL - W20

To cover the Fast Training Linux Course for WebMaster present the following parts:

• Part I. Internet UserGuide
• Part II. Advanced Web Programming
• Part III. Internet WebServer Setup

At the beginning we teach Web Programming language techniques starting with HTML then PERL and PHP covering also MySQL. The last part covers WebServer installation and configuration, as advanced as necessary to be used at updated daily.

Exercises

1. Visit w3.org
2. Check is Apache is running on your desktop

1. What is http? Is posible to transfer files with this protocol? What means the words: HTTP?
2. What is FTP? What means the words: FTP?
3. What means PERL? Who was the author?
4. What means PHP? Who was the author?
5. In what year was the Internet boom?
6. What means DNS?
7. What is Apache?
8. What Military US organization develop the TCP/IP protocol ?
9. What is the ideator of the HTML Language ?
10. What is the Linux protocol to handle e-mails?

Check the Interactive Exam Cram WebMaster: 

Internet Resources for this Chapter.

• http://www.kernel.org/
• http://www.apache.org/
• http://www.perl.com/
• http://www.w3c.org/
• http://www.sendmail.org/
• http://www.mysql.com/
• http://www.php.net/
• http://www.modssl.org/
• http://www.ssl.org/