Lindungi Email Anda dari Spamming

Kebutuhan e-mail saat ini merupakan hal yang penting dan tidak dapat dilepaskan dari kegiatan berinternet. Hampir semua orang yang mengenal internet pasti mempunyai e-mail address bahkan mempunyai lebih dari satu e-mail address, baik itu e-mail yang terdaftar di ISP atau dari situs yang memberikan fasilitas e-mail gratis. Hampir semua orang yang menggunakan e-mail pasti pernah mengalami masalah baik secara teknis ataupun nonteknis.

Dari sekian banyak masalah, ada satu masalah yang sangat mengganggu, yaitu junk mail atau e-mail sampah yang aktivitasnya disebut dengan "SPAM". Spam e-mail adalah mengirimkan suatu e-mail yang sama secara terus menerus ke penerima yang tidak menginginkan e-mail tersebut. Kebanyakan e-mail spam berisi iklan, penawaran dan lain sebagainya, sehingga memenuhi mailbox dan memperlambat proses download e-mail. Keterangan lebih lanjut mengenai spam dapat Anda lihat di http://spam.abuse.net/overview/whatisspam.shtml atau http://noc.cbn.net.id/spamming.php.

Banyak cara bagi para spawner (istilah bagi orang yang melakukan spam) mendapatkan alamat e-mail Anda, antara lain menggunakan program yang bisa mendapatkan alamat e-mail dari email yang diposting ke Usenet, mencarinya dari profile subscriber, menggunakan program web-crawler yang mencari alamat e-mail pada situs web, membelinya dari penyedia alamat email, mengambil informasi dari browser yang Anda gunakan saat Anda mengunjungi situs web mereka, dan terakhir bisa melalui virus internet.

Ada beberapa cara untuk menghindari spam dari sisi user, yaitu dengan cara tidak browsing ke situs-situs yang tidak aman (situs porno, situs software, situs penawaran), jangan memasukkan alamat e-mail utama pada situs yang meminta alamat
e-mail Anda, jangan membuka link-link yang tidak jelas di internet, menggunakan software firewall atau sejenisnya, dalam
hal ini software anti spam dan selalu melakukan update antivirus.

Sebenarnya, beberapa Webmail sudah menyertakan cara menanggulangi email spam dengan menyediakan fasilitas untuk memblok atau memfilternya. Selain itu, ada beberapa software yang dapat dipakai, baik software yang sifatnya freeware ataupun licensed untuk membantu dalam mengatasi masalah tersebut, seperti mailwasher, SaproxyPro, secretmaker dan banyak lagi yang bisa kita dapatkan di internet. Berikut adalah beberapa situs yang menyediakan software tersebut: www.mailwasher.net, www.statalabs.com, www.secretmaker.com, www.download.com, www.tucows.com dan sebagainya.

Dengan demikian Anda bisa melakukan pengecekan dan pengaturan e-mail, karena software ini menampilkan header dari e-mail yang ada di mailbox. Dari situ Anda bisa memfilter e-mail yang akan diterima sebelum men-download e-mail tersebut ke komputer, untuk menghemat waktu download e-mail yang tidak diinginkan. Selain itu, software-software ini juga dapat berfungsi sebagai pendeteksi e-mail yang efektif untuk penghapusan spam, jalan teraman untuk menghentikan penyebaran virus ke komputer kita.

Istilah Teknologi
Drunk Mouse
Ketika pointer kursor di monitor Anda bergerak ke sana kemari tak beraturan, biasanya disebabkan adanya kotoran dalam mouse Anda.

Batch
Sebuah metode pengorganisasian beberapa file ke dalam satu grup untuk keperluan pentransferan ataupun pencetakan. Hal ini untuk efisiensi dari transfer data itu sendiri.

Cross Post
Mengirimkan pesan ke beberapa newsgroups secara simultan. Aksi ini kerap mendatangkan masalah bagi orang lain yang menerima pesan tersebut secara berulang-ulang.

Ad Blocking
Sebuah frase yang menyatakan untuk tidak menayangkan iklan online tertentu, biasanya disebabkan iklan tersebut mengandung unsur porno atau berisikan program yang memberatkan komputer.

Edu
Salah satu dari daftar domain yang berkaitan dengan lingkungan akademik, umumnya diperuntukkan bagi universitas dan institut pendidikan.

Solusi Murah untuk Highly-Available Data

Jika Anda bergerak di bidang IT dan harus menangani beberapa server penting yang menyimpan begitu banyak data, maka hal yang paling menakutkan Anda adalah kejadian server crash, entah itu disebabkan oleh masalah pada hardware, software, atau masalah lainnya yang tidak Anda ketahui. Seluruh rekan kerja, pelanggan serta manajemen perusahaan Anda berharap sepenuhnya kepada Anda untuk memulihkan server yang crash dan mengembalikan data yang hilang. Berbagai pertanyaan muncul di benak Anda, apakah back up data aman dan up-to-date? Apakah back up data ada di tempat? Apakah back up data bisa di-restore dan dapat diandalkan? Kejadian seperti di atas adalah mimpi buruk yang lama sekali tidak ingin Anda alami.

Setiap layanan bergantung kepada tersedianya data. Untuk memberikan layanan apa pun, data haruslah mudah tersedia. Jika Anda menginginkan layanan tersebut highly-available, maka data yang Anda perlukan haruslah juga highly-available. Untuk mengurangi downtime pada solusi Anda yang sudah terbiasa menggunakan back up, yang paling umum adalah dengan cara menyediakan server kedua yang siap sedia untuk mengambil alih, baik dengan cara hot stand by atau cold stand by. Akan tetapi, kedua cara ini pun masih menyisakan masalah, yaitu jika server yang sedang aktif mati, Anda tetap akan kehilangan data yang dibuat setelah back up yang terakhir Anda lakukan.

Lalu apakah solusi untuk masalah data redundancy seperti ini? DRBD (Distributed Replicated Block Device) mungkin bisa memenuhi kebutuhan departemen atau perusahaan Anda. DRBD adalah solusi yang dapat menghemat data dan waktu kerja Anda, serta tentu saja menunjang karier Anda, karena DRDB merupakan realtime back up dengan replikasi (live atau online replication).

DRBD adalah solusi yang bisa dibilang paling murah dibandingkan solusi lainnya untuk masalah yang sama. Solusi lain seperti shared storage hardware, biasanya menggunakan storage device yang dihubungkan dengan beberapa node (melalui shared SCSI bus atau Fibre Channel) dengan harga yang sangat mahal. Dengan kemampuannya untuk bekerja melalui IP network, DRBD bisa lebih murah karena tidak perlu menggunakan hardware khusus seperti halnya storage devices.

Walaupun DRBD tidak memerlukan hardware khusus, tetap direkomendasikan untuk memiliki sebuah dedicated network link untuk replikasi datanya. Jika Anda menginginkan throughput yang tinggi, maka bottle neck di 10/100 megabit Ethernet dapat dihilangkan dengan menggunakan Gigabit Ethernet.

DRBD menyediakan mass storage device (block device), dan mendistribusikan device tersebut ke beberapa server, sehingga data yang tersimpan akan direplikasikan ke server lainnya secara realtime. DRDB me-mirror seluruh block device-nya melalui dedicated network. Selain software DRBD, diperlukan juga software cluster membership dan aplikasi yang Anda butuhkan untuk menggunakan block device tersebut.

Bagaimana Cara DRBD Bekerja?

Setiap server atau node berfungsi sebagai 'primary' atau 'secondary'. Aplikasi yang kita jalankan akan berjalan di server yang berfungsi sebagai 'primary', serta mengakses block device (/dev/nbX). Setiap data yang akan disimpan dikirim ke lokal harddisk (di bagian lower level block device) serta dikirim juga ke server atau node yang berfungsi sebagai 'secondary', pada bagian yang sama.

Jika server 'primary' gagal atau mati, aplikasi cluster (diantaranya heartbeat) otomatis mengubah server secondary menjadi primary, kemudian akan menjalankan aplikasi Anda di server secondary tersebut. Saat server 'primary' yang mati sudah normal kembali, maka server tersebut berubah menjadi 'secondary' dan secara otomatis mensinkronkan datanya ke server yang sekarang menjadi 'primary', seluruh proses ini tentu saja berjalan tanpa adanya interupsi pada proses yang sedang berjalan di background. Sinkronisasi ini adalah proses yang paling penting di DRBD, termasuk pemilihan apakah akan dilakukan full synchronization ataukah cukup incremental synchronization.

Membersihkan File-file dari situs yang Anda kunjungi

Setiap kali Anda browsing mengunjungi situs-situs di internet, Anda mungkin tidak sadar bahwa hampir semua file pada situs-situs tersebut telah tersimpan ke dalam harddisk. Proses ini dimaksudkan untuk mempercepat akses apabila Anda mengunjungi situs-situs itu kembali. Namun demikian, kalau tidak diperhatikan, hal ini bisa memakan tempat yang cukup banyak di harddisk Anda. Lama kelamaan akan mcngganggu kinerja komputer. Karena itu, sebaiknya secara berkala harddisk perlu dibersihkan dari file-file yang tidak diperlukan lagi.

Berikut adalah langkah-langkah yang dapat Anda lakukan untuk melakukan hal tersebut.
1. Klik "Start" > "Programs" > "Accessories" > "System Tools" > "Disk Cleanup".
2.
Akan muncul kotak "Select Drive". Pastikan bahwa kolom "Drives" adalah (C:). Karena pada drive C: inilah biasanya folder Temporary Internet Files disimpan. Folder ini menyimpan file-file yang pernah dikunjungi (browsing) di Internet. Klik "OK".
3.
Setelah muncul dialog box "Disk Cleanup for (C:)", Anda akan diberikan pilihan, folder mana yang akan dikosongkan. Beri tanda centang di depan folder "Temporary Internet Files", "Downloaded Program Files", "Recycle Bin" dan "Temporary Files".
4. Klik "OK".
5. Klik "Yes" pada kotak konfirmasi.

Selanjutnya proses clean up akan berlangsung. Lamanya tergantung dari seberapa banyak file yang dihapus. Biasanya tidak ada pemberitahuan lagi apabila proses clean up sudah selesai. Selanjutnya komputer sudah bisa digunakan lagi

Anda juga dapat membersihkan jejak browsing Anda dengan cara menghilangkan history pada Internet Explorer. Caranya:
1. Buka program Internet Explorer Anda. Pada toolbar, klik "Tools" > "Internet Options".
2.
Selanjutnya muncul kotak "Internet Options". Klik tombol "General". Klik tombol "Delete Files". Untuk menghemat waktu pada saat awal browsing ke Internet, sebaiknya Anda pilih "about:blank" sebagai default homepage Anda.
3.
Beri tanda centang pada "Delete all offline contents". Ini dimaksudkan untuk menghapus semua file offline pada temporary
files.
4. Klik "OK"
5. Klik tombol "Clear History". Hal ini dimaksudkan untuk menghapus daftar alamat URL yang pernah dikunjungi.
6.
Pada kotak konfirmasi , klik "Yes".
7. Klik "OK" pada kotak "Internet Option".

Selamat mencoba!

Website C Card

Komunitas C Card yang sedemikian besar, alangkab sayangnya jika tidak dihimpun dalam satu wadah dimana antar anggotanya dapat saling berbagi pengalaman dan hobi sesuai dengan interest-nya masing-masing. Berbagai kemudahan dan fasilitas yang Anda dapatkan setelah bergabung dengan komunitas C Card akan terasa lebih lengkap dengan adanya suatu wadah bersama untuk berbagi.
Dihadirkanlah website khusus C Card sebagai media bagi komunitas C Card CBN ini. C Card Website dikembangkan khusus untuk Anda, para pemegang C Card yang tak ingin ketinggalan informasi terkini seputar C Card. Di website ini, CBN, para merchant dan pemegang C Card dapat saling berinteraksi. Dengan adanya website khusus ini, semua pihak dapat lebih mengenal satu lama lain sehingga semakin menyemarakkan komunitas C Card.
Bagaimana bentuk dan apa saja isi situs C Card ini? Dalam website ini, Anda dapat memperoleh semua informasi mengenai C Card di All About C Card seperti fungsi C Card, cara mendapatkan kartu dan semua informasi yang Anda butuhkan tentang C Card. Untuk mengenal lebih dekat merchant C Card, di Merchant's Profile akan dikupas tuntas satu per satu tentang usaha dan kelebihan masing masing merchant, yang membuat Anda mengenal lebih dekat lagi siapa dan apa di balik merchant tersebut. Tak hanya itu, di situs ini Anda juga dapat menelusuri daftar tempat hang out atau tempat berlibur favorit di Merchant's List, serta berbagai kemudahan yang ditawarkan untuk Anda. Simak juga penawaran khusus dari merchant-merchant C Card di Promo of The Month.
Jangan lewatkan kuis berhadiah menarik kerjasama CBN dan para merchant dalam Quiz . Untuk Anda yang ingin bergabung menjadi merchant, dapatkan informasinya di How to Become A Merchant.
Cukup lengkap bukan? Semua informasi ada di situs C Card. Kunjungi situs http://ccard.cbn.net.id dan jelajahi dunia C Card. Selamat datang di komunitas C Card!

Cara Mengganti Wallpaper Hand Phone

Mempunyai tampilan yang menarik pada layar ponsel (wallpaper) membuat kita merasa senang. Yang lebih menarik, wallpaper sangat mudah untuk diganti dengan wallpaper lain yang lebih menarik. Berikut ini adalah tips mengganti wallpaper agar sesuai dengan selera Anda

1. Koleksi wallpaper di ponsel
Cara termudah dengan mengganti wallpaper dengan sejumlah koleksi gambar yang ada di dalam handset. Cara menggantinya dapat dilakukan secara manual dengan mudah

2. Tukar Koleksi dengan teman
Bila Anda bosan dengan koleksi wallpaper di ponsel, Anda dapat menggantinya dengan meminta koleksi teman dimana ponsel harus memiliki fitur infrared atau bluetooth sehingga dapat saling bertukar wallpaper

3. Download gambar di internet
Anda juga dapat browsing di situs internet untuk mendapatkan berbagai macam gambar wallpaper. Ada yang berbayar tapi banyak juga yang menyediakan secara gratis. Namun untuk dapat mendownload gambar wallpaper ini membutuhkan koneksi dari komputer ke handset anda, agar gambar yang telah Anda simpan di komputer dapat pindah ke ponsel. Dapat menggunakan kabel data / infrared adapter / bluetooth adapter. Alat ini tersedia di sejumlah toko ponsel

Running CGI Scripts With Perl, Apache and Windows

Installing ActivePerl

Click the following link to download ActivePerl. Be sure to read this page's contents, since Win95 users will have to download DCOM for Windows 95.
Double-click on the *.msi file. When you get to the part where you choose an install directory, make sure it's the same as the Perl location on your host site. For example, if Perl is located in /usr/bin/, create a directory c:\usr and install ActivePerl into that (it will create its own /bin directory). Your directory structure should look like this when you're done:

c:\usr
\bin
perl.exe
etc.
\html
Perl documentation
\lib
Perl's root library
\site
\lib
Perl's site library
Note that Perl differs from ActivePerl in that it makes /site a subdirectory of /lib (Perl's root library).
When it asks you which elements you want installed, you should be aware that mod_asp supplies PerlScript support to Apache (Thanks to Jerrad Pierce for bringing me up to date on this). So select Perl for ISAPI and PerlScript, if you're going to be working with these things.
Next, choose to add perl.exe to your path, but don't associate .pl files with perl.exe. Unlike WinNT, you can't run Perl scripts in Win95/98 by double-clicking them; you have to open a command prompt window.
That should be it. When ActivePerl is done installing, reboot your computer if you're not using XP or NT.

Here are two tests:

Open your command prompt window (C:\WINDOWS\COMMAND.COM), type perl -v and hit Return. You should get a message saying This is Perl..., etc..
Create the following script in a text editor like Textpad or Notepad (see Editing the Script):

#!/usr/bin/perl -w
print "Hello world, it works!\n";

Save it somewhere, like c:\tmp\test.pl. Now open the command prompt window and type:

perl c:\tmp\test.pl

Hit the Return key. The message Hello world, it works! should be printed on your screen.


Configuring Apache to permit CGI

In order to get your CGI programs to work properly, you'll need to have Apache configured to permit CGI execution. There are several ways to do this.

ScriptAlias

The ScriptAlias directive tells Apache that a particular directory is set aside for CGI programs. Apache will assume that every file in this directory is a CGI program, and will attempt to execute it, when that particular resource is requested by a client.

The ScriptAlias directive looks like:

ScriptAlias /cgi-bin/ /usr/local/apache/cgi-bin/

The example shown is from your default httpd.conf configuration file, if you installed Apache in the default location. The ScriptAlias directive is much like the Alias directive, which defines a URL prefix that is to mapped to a particular directory. Alias and ScriptAlias are usually used for directories that are outside of the DocumentRoot directory. The difference between Alias and ScriptAlias is that ScriptAlias has the added meaning that everything under that URL prefix will be considered a CGI program. So, the example above tells Apache that any request for a resource beginning with /cgi-bin/ should be served from the directory /usr/local/apache/cgi-bin/, and should be treated as a CGI program.

For example, if the URL http://www.example.com/cgi-bin/test.pl is requested, Apache will attempt to execute the file /usr/local/apache/cgi-bin/test.pl and return the output. Of course, the file will have to exist, and be executable, and return output in a particular way, or Apache will return an error message.

CGI outside of ScriptAlias directories

CGI programs are often restricted to ScriptAlias'ed directories for security reasons. In this way, administrators can tightly control who is allowed to use CGI programs. However, if the proper security precautions are taken, there is no reason why CGI programs cannot be run from arbitrary directories. For example, you may wish to let users have web content in their home directories with the UserDir directive. If they want to have their own CGI programs, but don't have access to the main cgi-bin directory, they will need to be able to run CGI programs elsewhere.

Explicitly using Options to permit CGI execution

You could explicitly use the Options directive, inside your main server configuration file, to specify that CGI execution was permitted in a particular directory:


Options +ExecCGI


The above directive tells Apache to permit the execution of CGI files. You will also need to tell the server what files are CGI files. The following AddHandler directive tells the server to treat all files with the cgi or pl extension as CGI programs:

AddHandler cgi-script cgi pl

.htaccess files

A .htaccess file is a way to set configuration directives on a per-directory basis. When Apache serves a resource, it looks in the directory from which it is serving a file for a file called .htaccess, and, if it finds it, it will apply directives found therein. .htaccess files can be permitted with the AllowOverride directive, which specifies what types of directives can appear in these files, or if they are not allowed at all. To permit the directive we will need for this purpose, the following configuration will be needed in your main server configuration:

AllowOverride Options

In the .htaccess file, you'll need the following directive:

Options +ExecCGI

which tells Apache that execution of CGI programs is permitted in this directory.


Writing a CGI program

There are two main differences between ``regular'' programming, and CGI programming.

First, all output from your CGI program must be preceded by a MIME-type header. This is HTTP header that tells the client what sort of content it is receiving. Most of the time, this will look like:

Content-type: text/html

Secondly, your output needs to be in HTML, or some other format that a browser will be able to display. Most of the time, this will be HTML, but occasionally you might write a CGI program that outputs a gif image, or other non-HTML content.

Apart from those two things, writing a CGI program will look a lot like any other program that you might write.
Your first CGI program

The following is an example CGI program that prints one line to your browser. Type in the following, save it to a file called first.pl, and put it in your cgi-bin directory.

#!/usr/bin/perl
print "Content-type: text/html\r\n\r\n";
print "Hello, World.";

Even if you are not familiar with Perl, you should be able to see what is happening here. The first line tells Apache (or whatever shell you happen to be running under) that this program can be executed by feeding the file to the interpreter found at the location /usr/bin/perl. The second line prints the content-type declaration we talked about, followed by two carriage-return newline pairs. This puts a blank line after the header, to indicate the end of the HTTP headers, and the beginning of the body. The third line prints the string ``Hello, World.'' And that's the end of it.

If you open your favorite browser and tell it to get the address

http://www.example.com/cgi-bin/first.pl

or wherever you put your file, you will see the one line Hello, World. appear in your browser window. It's not very exciting, but once you get that working, you'll have a good chance of getting just about anything working.


But it's still not working!

There are four basic things that you may see in your browser when you try to access your CGI program from the web:

1. The output of your CGI program
Great! That means everything worked fine.

2. The source code of your CGI program or a "POST Method Not Allowed" message
That means that you have not properly configured Apache to process your CGI program. Reread the section on configuring Apache and try to find what you missed.


3. A message starting with "Forbidden"
That means that there is a permissions problem. Check the Apache error log and the section below on file permissions.


4. A message saying "Internal Server Error"
If you check the Apache error log, you will probably find that it says "Premature end of script headers", possibly along with an error message generated by your CGI program. In this case, you will want to check each of the below sections to see what might be preventing your CGI program from emitting the proper HTTP headers.

File permissions
Remember that the server does not run as you. That is, when the server starts up, it is running with the permissions of an unprivileged user - usually ``nobody'', or ``www'' - and so it will need extra permissions to execute files that are owned by you. Usually, the way to give a file sufficient permissions to be executed by ``nobody'' is to give everyone execute permission on the file:

chmod a+x first.pl

Also, if your program reads from, or writes to, any other files, those files will need to have the correct permissions to permit this.

The exception to this is when the server is configured to use suexec. This program allows CGI programs to be run under different user permissions, depending on which virtual host or user home directory they are located in. Suexec has very strict permission checking, and any failure in that checking will result in your CGI programs failing with an "Internal Server Error". In this case, you will need to check the suexec log file to see what specific security check is failing.

Path information
When you run a program from your command line, you have certain information that is passed to the shell without you thinking about it. For example, you have a path, which tells the shell where it can look for files that you reference.

When a program runs through the web server as a CGI program, it does not have that path. Any programs that you invoke in your CGI program (like 'sendmail', for example) will need to be specified by a full path, so that the shell can find them when it attempts to execute your CGI program.

A common manifestation of this is the path to the script interpreter (often perl) indicated in the first line of your CGI program, which will look something like:

#!/usr/bin/perl

Make sure that this is in fact the path to the interpreter.

Syntax errors
Most of the time when a CGI program fails, it's because of a problem with the program itself. This is particularly true once you get the hang of this CGI stuff, and no longer make the above two mistakes. Always attempt to run your program from the command line before you test if via a browser. This will eliminate most of your problems.
Error logs

The error logs are your friend. Anything that goes wrong generates message in the error log. You should always look there first. If the place where you are hosting your web site does not permit you access to the error log, you should probably host your site somewhere else. Learn to read the error logs, and you'll find that almost all of your problems are quickly identified, and quickly solved.


What's going on behind the scenes?

As you become more advanced in CGI programming, it will become useful to understand more about what's happening behind the scenes. Specifically, how the browser and server communicate with one another. Because although it's all very well to write a program that prints ``Hello, World.'', it's not particularly useful.

Environment variables

Environment variables are values that float around you as you use your computer. They are useful things like your path (where the computer searches for a the actual file implementing a command when you type it), your username, your terminal type, and so on. For a full list of your normal, every day environment variables, type env at a command prompt.

During the CGI transaction, the server and the browser also set environment variables, so that they can communicate with one another. These are things like the browser type (Netscape, IE, Lynx), the server type (Apache, IIS, WebSite), the name of the CGI program that is being run, and so on.

These variables are available to the CGI programmer, and are half of the story of the client-server communication. The complete list of required variables is at http://hoohoo.ncsa.uiuc.edu/cgi/env.html

This simple Perl CGI program will display all of the environment variables that are being passed around. Two similar programs are included in the cgi-bin directory of the Apache distribution. Note that some variables are required, while others are optional, so you may see some variables listed that were not in the official list. In addition, Apache provides many different ways for you to add your own environment variables to the basic ones provided by default.

#!/usr/bin/perl
print "Content-type: text/html\n\n";
foreach $key (keys %ENV) {
print "$key --> $ENV{$key}
";
}

STDIN and STDOUT

Other communication between the server and the client happens over standard input (STDIN) and standard output (STDOUT). In normal everyday context, STDIN means the keyboard, or a file that a program is given to act on, and STDOUT usually means the console or screen.

When you POST a web form to a CGI program, the data in that form is bundled up into a special format and gets delivered to your CGI program over STDIN. The program then can process that data as though it was coming in from the keyboard, or from a file

The ``special format'' is very simple. A field name and its value are joined together with an equals (=) sign, and pairs of values are joined together with an ampersand (&). Inconvenient characters like spaces, ampersands, and equals signs, are converted into their hex equivalent so that they don't gum up the works. The whole data string might look something like:

name=Rich%20Bowen&city=Lexington&state=KY&sidekick=Squirrel%20Monkey

You'll sometimes also see this type of string appended to the a URL. When that is done, the server puts that string into the environment variable called QUERY_STRING. That's called a GET request. Your HTML form specifies whether a GET or a POST is used to deliver the data, by setting the METHOD attribute in the FORM tag.

Your program is then responsible for splitting that string up into useful information. Fortunately, there are libraries and modules available to help you process this data, as well as handle other of the aspects of your CGI program.


CGI modules/libraries

When you write CGI programs, you should consider using a code library, or module, to do most of the grunt work for you. This leads to fewer errors, and faster development.

If you're writing CGI programs in Perl, modules are available on CPAN. The most popular module for this purpose is CGI.pm. You might also consider CGI::Lite, which implements a minimal set of functionality, which is all you need in most programs.

If you're writing CGI programs in C, there are a variety of options. One of these is the CGIC library, from http://www.boutell.com/cgic/


For more information

There are a large number of CGI resources on the web. You can discuss CGI problems with other users on the Usenet group comp.infosystems.www.authoring.cgi. And the -servers mailing list from the HTML Writers Guild is a great source of answers to your questions. You can find out more at http://www.hwg.org/lists/hwg-servers/

And, of course, you should probably read the CGI specification, which has all the details on the operation of CGI programs. You can find the original version at the NCSA and there is an updated draft at the Common Gateway Interface RFC project.