Many beginning web programmers become familiar with the language through books. The book is undoubtedly very important and necessary, but it provides examples (for beginners) that are inherently not correct from the point of view of script stability and portability. By stability we mean the possibility of errors of various types occurring, by portability - the same thing, but when transferring a script from a local machine at home to the hosting provider's server.

Below I would like to immediately show novice web developers how to learn to write scripts right away, so that later they do not experience unnecessary problems and do not “catch” errors that pop up out of nowhere.

I’ll say right away that I encountered this myself, so all this went through my torment….

I will consider the following points:

2. Where is the “@” buried?
3. register_globals = Off and nothing else.
4. Basic aspects of syntax. Literal or not literal...

1. Setting up PHP for the local machine and on the server.

Why am I starting with this chapter? The fact is that many people immediately disable the display of all errors on the local machine. It is not right. Instead of staring blankly at the monitor and looking for where the semicolon appears to be missing, you can immediately understand what’s going on based on the error generated by PHP.

But first I want to make a small digression on how to configure PHP, like Apache modul or fast-CGI.
The best option is to configure it as a web server module. To do this in configuration file httpd.conf of the Apache web server we write the following lines:

LoadModule php4_module D:/bin/php/sapi/php4apache2.dll AddType application/x-httpd-php .php .phtml .php4 .php

The differences from FastCGI are the following. First. With FastCGI, php.ini will be loaded into the web server's memory approximately every second time when the script is launched; when installed as an Apache module, the PHP configuration will be loaded only when the web server is loaded or restarted; of course, the performance and load on the server will be less. Additionally, certain features are not available when installed as fastCGI. A novice programmer won't need them, but when developing a large Internet application you may run into problems. It's better to prevent problems.

Now let's move on to the configuration of PHP itself. In the php.ini configuration file, we must set the following directives with the values ​​written below:

error_reporting = E_ALL display_errors = On display_startup_errors = On

Whether or not to write errors in log files is at your discretion.
On a server in a hosting company, be sure to turn off all these directives for security purposes, so that a potential attacker cannot find out the paths where your scripts are located. But it's good when you already publish your script in global network, it shouldn't throw any errors.
Besides

short_open_tag = Off To prevent using

By default, the max_execution_time directive has a value of 30, but for faster operation, it is better to set it lower. If you are stuck on something, then 10 seconds is enough to understand it.

register_globals = Off register_argc_argv = Off

I'll go into more detail about this in Chapter 3...

magic_quotes_gpc = Off

Very often, novice web developers do not understand the difference between ‘ and “, so we turn off the directive. In Chapter 4 this point will be illustrated with an example...

2. Where is the “@” buried?

This is perhaps the most basic mistake made by novice programmers – using “@”. This symbol, before any operator, suppresses the output of an error and its recording in the log. It does not allow you to track the error at the debugging stage, and you are frantically trying to understand what is wrong.

A striking example. Suppose we put the “@” symbol before the line $f = fopen(“fle.txt” , “w+”);. If we take only the most common errors that can occur during a subsequent fwrite, for example, then these are: a) no access rights to the file, b) the file does not exist, c) fopen cannot be called in safe mode. Can you imagine how many possible errors there can be? A lot. And how are you going to find out which error occurred specifically for you, because you suppressed their output with the “@” symbol.

Therefore, we strictly prohibit you from using @.

You may ask, how can you then prevent the error from being displayed?
In order for an error not to be displayed, it must either be prevented, as in the case of files, that is, a) check the file for existence, b) check whether it is possible (you have the rights) to write something into it is_writeable();.

In other cases, such as when using mysql_connect(); you need to check the value that the function returns. As a rule, it can be used to determine whether there is an error or not. Typically, an error will return FALSE, NULL, or the empty string.

This will allow you to give the user a non-empty page if, for example, he tried to access information (?n=14), but the information is stored in your files, and file 14 does not exist, and the text message: “Information not found” .

“Catching” errors is also a very important aspect of security when running a script.

3. register_globals = Off and nothing else.

If in the first two chapters I focused on those points that a novice programmer will immediately encounter, then in this chapter I will talk about a point that will appear later... everyone often encounters it when transferring a script (already ready) to a hosting server provider. Personally, it took me a long time to get used to register_globals = Off, so fellow novice programmers, immediately turn this directive off. In addition, this point is VERY IMPORTANT in ensuring the security of the script.

So. What's the big deal? First, let's look at the case where we have register_globals = On. As you probably already know, data can be transferred to a script in three ways, I said roughly, in fact there are two of them. The first is GET, i.e. the data is transmitted through the address bar of the browser after the “?” character, the second is POST, when used, the data is transmitted in an implicit form to the user. The POST method is typically used to submit form data. Well, the third one is Cookies transferred from the user to the script.

Let's consider this case. We have a form that is located at index.php? form. The form has several text fields fields. Let it be family, name, phone. The form is sent to the same index.php but using the POST method. After checking all the data, we wrote down two Cookies for the user with the names family and form, in the second we recorded the time of access to the form, for example.

Let's imagine that part of our index.php file consists of the following code, i.e. if the user has already entered data on the form, they are shown to him; if not, the form is displayed. And all this at index.php?form.

"; print "You were here: " . $form ."
"; ) else ( // Show our form. ) ) ?>

Now think about it.. What will happen in $form, because we are passing the variable both as a GET parameter and through Cookies. Here. Then you will frantically search for an error in why your $form is empty or vice versa.

Those. in fact, it all comes down to the fact that it is possible to replace all variables. In fact, this is a significant disadvantage in security, since there is a very high probability that an attacker will be able to look at some important files on the server.

Now let's talk about how to implement this under register_globals = Off

There are several global arrays in PHP. $_GET, $_POST, $_COOKIE, $_REQUEST (combining the first three, not recommended for security reasons), $_FILES (for downloading files), $_SESSIONS (sessions), $_SERVER (server variables), $_ENV (environment variables) , $GLOBALS (combines everything).

What does it mean. Below I will simply rewrite the script I gave earlier for register_globals = Off..

"; print "You were here: " . $_COOKIE["form"] . "
"; ) else ( // Show our form. ) ?>

Now there will be no problems.
Just in case, let me clarify that in $_****[‘name’] instead of name you need to write the name of the text field or Cookie or parameter passed from the address bar.

In this chapter I want to look at the following small example. Again, let's first look at an example with register_globals enabled.

The script will output a value of $a equal to 7. I.e. Essentially, we have variables available both inside and outside the function. This is not good, because in a large script there can be a lot of such variables $a, and as a result, in any function the value of a variable can be changed and the result of script execution will be unpredictable.
Now, if the same code is executed with register_globals = Off, it will print 2. Because changes to the $a variable inside the function will not affect the $a variable in the main body of the script. Here you need to read the manual about the scope of variables.
If we need to get this seven, then we need to return the value of local $a from the function and store this value in global $a.

4. Basic aspects of syntax. Literal or but literal...

1. Again, many novice programmers do not understand the difference between the entry: $_POST['pole'] and $_POST. The first option is syntactically correct, but the second is not. PHP will not try to find the pole element, but an element with a name that is stored in the pole constant, which you do not have.

Experienced users are always trying to simplify their work with a PC and will probably want to know how to make a script on a computer and what it is.

What is a batch file

Batch file is a term that PC users often hear. Essentially, it's a way of doing things without actually doing them. A set of commands is also known as a script.

Hence, it is a script document used to automate tasks on DOS, Windows and OS/2 operating systems.

Many users are familiar with the term command line interpreter, known as CMD or command line. It accepts various directives as keyboard input and processes them.

The batch document acts as an intermediary between users and the command line. Elements with the format bat, cmd and btm contain CMD commands. When such a document is launched, the directives written in it are executed in the interpreter in sequential order. Otherwise, they will need to be entered manually, line by line.

Why do you need a script?

The script saves the user time. Otherwise, you will need to enter the same directives over and over again.

For example, you can schedule the operating system to shut down after a certain time using CMD. When the desired document is created, you just need to double-click on it. It will start and the system will turn off after the set time.

If a developer wants to use the command line on a computer when installing software, they can do so by including the file in the installation packages. Otherwise, you will have to run the commands manually.

When creating a batch element, you can also include loops (for), conditional statements (if), control statements (go to), etc. It is also possible to run one document from another using the call function.

Basic bat commands

It will be useful to know some bat directives that will help you create basic batch files:

• Title is used to change the title text displayed at the top of the CMD window.
• Echo – Displays the input series as output. It is advisable to use the ON or OFF option for ECHO to turn echo on or off. This function allows you to display on the screen those directives that are being executed.
• Pause is used to stop script execution.
• Exit – function to exit the interpreter.
• Cls is used to clear the screen of all commands.
• :: - Add a comment. The command line ignores any text written as a comment.

The above are the internal directives that come with the OS. A batch script can also support external commands. They are added when new software is installed on the system. For example, if you have Google Chrome installed on your computer, you can use the “chrome” function in the CMD window.

All these commands can help you create a simple bat file. It is possible to improve your script by learning more functions from the CMD list.

Creating a bat script on Windows

On Windows, you can create a batch file using the steps below or the steps mentioned in the MS-DOS Command Prompt section. If it is convenient to use standard programs, you can use any text editor (for example, Notepad or WordPad) to create batch documents.

In order to create a script with the bat extension in Notepad, you should perform the following steps:

1. Click Start.
2. Type Notepad in the Run box and press Enter. You can also use any similar text element editor, for example Notepad++.
3. When Notepad opens, enter the following lines or copy and paste them.
4. Click "File" then "Save" and navigate to the folder where you want to save. You can enter test.bat as the name. If the operating system version has a "Save As" option, select "All files", otherwise it is saved as text. After completing these steps, click the “Save” button and exit the notepad.
5. To launch a document, double-click on it. A CMD window will open automatically with the desired output. After completion of execution, the window automatically closes.
6. You can try adding echo on in step 2 to see what happens on each line.

The steps to create scripts are almost the same whether you have Windows 10, 8.1, 7 or even XP.

It is worth noting that you can use the cmd extension instead of the bat extension.

Creating a bat file in MS-DOS

To create a batch element in MS-DOS or Windows Command Prompt, it is important to follow these steps:

It is useful to note: if there is a need to add more lines to a batch element, just enter edit test.bat to open it for editing. Some versions of MS-DOS and boot floppies may not have an edit directive.

If so, you must either enter edit.com or use the copy con function.

How to write scripts for an operating system, websites, or just games? The answer to this, believe me, is an easy question and will be discussed within the framework of this article.

general information

It is highly desirable to have at least minimal knowledge of programming. But if something seems incomprehensible, then an article or two will help fill the gap. First, let's define what a script is. This is the name for an algorithm written in certain programming languages ​​that is stored on a person’s computer and can interact with certain files, programs such as browsers and system settings. All this allows you to significantly supplement standard capabilities and create automated assistants that will take on part of the work.

Let's start working with browsers

This is perhaps one of the easiest activities. If we write scripts in JavaScript, then an ordinary notepad and knowledge of this programming language are enough. True, there are also disadvantages here. So, every person who has the same Notepad will be able to see what the script is. And if he has bad intentions, and there is a vulnerability in the code, then problems may arise. Answering the question of how to learn to write scripts in JavaScript, it should be noted that to do this, it is enough to study this programming language. In order to create better and more complex programs, you can use various libraries. But they require appropriate web browser extensions. And when changing computer equipment, you will have to make additional settings. And when using third-party developments, you need to make sure that the script will not send user data to third-party services. It should be noted that each browser has its own specific limitations. But in general, you can do almost anything with their help. Why are they written in such cases? They are needed when human activities need to be automated.

We work with the Windows operating system

Let's say we need to change the computer configuration. There is a wide range of graphic tools for this, but, alas, they do not cover everything. Therefore, it is often necessary to create system scripts. They have the extension .bat. Every person who works at a computer for more or less a long time has already encountered such files. But how to write scripts for Windows? For this we will need the same Notepad. First, create a new text file. It is necessary to record system commands in it. After this, you need to change the file extension to .bat. And all that remains is to launch this development. If everything is correct, then the commands will be executed successfully, as you can see. But in case of errors or illiterate code writing, at best, nothing will happen. Therefore, it is better to understand what you are writing down. Simply taking code from somewhere and mindlessly inserting it is absolutely not recommended! This can lead to significant problems with the operating system. And you’ll be lucky if such dangerous actions were done from a guest account. After all, a command from an administrator can turn a computer into a “brick”.

What about Linux?

It should be remembered that Windows is not the only operating system. There is also Linux, which is quite popular. How to write scripts in this operating system? They are created using a shell - a special command interpreter, which is the interface between a person and the operating system kernel. In Linux, scripts are essentially just a file that lists system commands. It's simple and convenient at the same time. But the shell needs to know how such a file should be processed. By default it just reads. And if you need to execute, then the “#!” construction is used, which must be placed before the command. All scripts have the extension .sh. It should be noted that you can do quite a lot of complex things with their help. For example, backing up files. In general, there are extremely many use cases.

Learning to write scripts

So, first we need to decide on the environment where we will type the code. Almost always, one Notepad is enough for this. But it is not very convenient to display the structure of structures; moreover, operators and other elements are not highlighted. Therefore, Notepad++ can be offered as a worthy alternative. For those who know English, it is not so difficult to translate that this is also a “Notepad”. But with expanded capabilities. This small but very nice development is aimed primarily at programmers. In it you can enable the display setting of almost everything that is available. There is a convenient code display tool and many other, albeit small, but nice little things that will make the writing process more comfortable. In general, the question “where to write scripts” has received many different answers, each of which offers its own twist. There are also very sophisticated environments, with emulators and many debugging tools. Choose what your heart desires. After this, you need to take care of your knowledge. Help on the programming language or operating system commands is suitable as a basis. For more advanced study, you can read several books that explain the features of machine logic and code processing.

Real-time training services

If you are interested in learning how to write scripts, then you should not discount the possibility of learning with the help of information educational technologies. What does such a “programmer forge” look like? According to the program, compiled according to the opinion of experienced developers, a beginner is led from the easiest to the most difficult moments. Thus, dynamic data updating can initially be studied in order to subsequently move on to creating socket servers. And the person undergoes training slowly, step by step, absorbing the maximum amount of data. Therefore, if difficulties arise, you can turn to them for help. It’s not a fact that the first one you come across will satisfy all your needs, but then you’ll just have to try something different.

Why study?

Many people are interested in how to write scripts for games. Well, this is not very difficult, but it is not the only use of such a feature. But let's look at the game as an example. Let’s say a person likes to play some kind of entertainment on a certain website. But, alas, it stipulates that it is necessary either to invest your money, or to carry out certain actions for a long time and monotonously. And if the second path was chosen, then scripts are exactly what is needed here. This can also be used in stationary games on a computer. There are characters controlled by artificial intelligence, and in order to fight with it, you can create your own version of the AI, thus arranging a battle between the computer and itself (and for easier passage). But scripts can be successfully used not only in games. Let's say that there is a website of a serious company. An important aspect is maximum support for communication with clients. And for this, a small form is added in the form of a script, with which you can get expert advice online. There are many possible uses!

Conclusion

Alas, it is very difficult to convey within the framework of this article how to write scripts correctly. You can, of course, use general phrases about how the code should take up less space, be optimal, and much more, but you can really understand this only in practice. After all, only experience and the search for optimal solutions can help in implementing programs in such a way that they fulfill their “responsibilities” with minimal effort. In programming in general, and not just in writing scripts, a lot depends on practice! Therefore, you need to constantly learn, improve and think about how to implement the task in the best possible way.

Instructions

Depending on where the script is executed, scripts are divided into “client” and “server”. When going to some address on the network, we send the URL of the page of interest to the server, and it runs the script located at the specified address. The script, performing the actions programmed in it on the server, assembles the page from the necessary blocks and sends it to the browser. This is a server script. Having received the page, the browser on ours renders it for us and, if the received page code contains some kind of script, then it is already executing this script. This is a client script.
In order for a server or browser to read, understand and execute a script, it must be compiled and written according to rules known to them. Such sets of rules are called scripting programming languages. Most server-side scripts are now written in PHP, and most client-side scripts are now written in JavaScript. To write a script, it is enough to have a regular text editor - notepad. But for constant programming of scripts, you cannot do without a specialized editor. Such an editor takes on the lion's share of the routine work of writing scripts, leaving the programmer more time for creativity.
Let's write a simple script in server-side PHP. The first line should inform the performer that the script begins from this point. In PHP, this opening tag looks like this:Between these two tags are instructions - the language. For example, print the inscription left by O. Bender on the Caucasus rocks like this: echo (“Kisya and Osya were here”); And the instruction to show the current time in the HOUR:MINUTE format is written like this: echo date("H:i"); Complete A PHP script composed of these statements would look like this:echo date("H:i");
echo ("Kisya and Osya were here!");?>After executing this script by the server executing program (language interpreter), the page would look like this:

And the same script in client JavaScript will look like this: var now = new date();
document.write("In");
document.write(now.getHours() + ":" + now.getMinutes());
document.write ("Kisya and Osya were here!"); Here the line var now = new date() commands the script executor to create a new virtual object called "now", which represents the current date and time. document.write() is a command to write what is specified in parentheses on a page, and the commands now.getHours() and now.getMinutes() instruct to retrieve the current hour and minute from the “now” object.
For greater clarity, all that remains is to combine these two scripts into one file, save it on the server and type the URL in the address bar of the browser. As a result, we will see identical lines, one of which was executed according to our script on the server (by the PHP interpreter), and the other on our computer (by the JavaScript interpreter).

What is a script? A script is a program written in a web programming language for websites that solves any dynamic problems on the website, be it creating a shopping cart for a customer or organizing correspondence on the website or voting in general, it fulfills any need that cannot be implemented using standard html or css means. Scripts are almost the main component of any website; it is with the help of scripts that a website turns from an ordinary hand-drawn page into a multifunctional structure, and it is impossible to do without scripts.
Almost any script can be adapted to a specific site, configured and implemented. In this section you are offered very interesting and useful scripts that will help you make your website more convenient and diverse.

This is an updated version of the well-known and beloved CMS Wordpress, which runs the majority of blogs on the Internet. The version is completely Russified and correct. In this version, a lot has been improved and finalized, for example, the text editor has been improved, a new view has been created for the image library, a new plugin directory, etc. You can download Wordpress 4 and have a beautiful blog today.

An excellent, powerful forum that has enormous potential and, best of all, it is also free. Version 3 is a logical continuation of the well-known phpbb2, but of course there is much more functionality, quality, and all kinds of improvements. A good cms that is in no way inferior to its paid counterparts.

Read instructions for installing and configuring the phpBB3 forum script.

This is the most popular build of one of the best CMS. Based on it, you can create projects of almost any complexity, from a personal page to a multi-level online store. The beauty of this CMS is its ease of use and fairly simple setup, which gives you great opportunities in terms of creating websites. Joomla 2.5.6 is a completely free CMS with a huge set of plugins and all kinds of templates.

Joomla is a set of scripts written in the PHP programming language. This is a ready-made and free engine for your website. Joomla! tries to keep things as simple as possible while still providing great features. Finally, people new to programming can have a system for fully managing their websites without spending exorbitant amounts of money on closed-source software. Usually a web server is the prerogative of hosters, but you can quite simply and quickly install D.E.N.W.E.R., which will install a ready-made web server software package on your computer and on which you can deploy and install CMS Joomla. Version of Joomla! 1.5.12 with localized demo materials and pre-installed Russian dialogue language. This distribution is no different from the standard one, except for pre-installed Russian language localization packages, demo materials in Russian, TinyMCE language files and license text displayed during installation.

In fact, it is a mini Yandex on your website. Site search script without using MySQL. Suitable for most small and medium-sized sites. Uses indexing, which significantly reduces search time. Indexes ~1Mb in 1 second (the speed depends on the nesting of folders and the structure of your pages). The search takes from a fraction of a second (depending on the complexity of the query and the weight of the index) to...

WordPress is a free, open source CMS distributed under the GNU GPL. WordPress is one of the most popular blogging platforms today. Using this script, you can make a website with huge functionality, from a simple page with posts, to a multifunctional site with user registration, and all kinds of services, thanks to a large number of plugins. There are also a huge number of free templates written for this CMS that will help make your blog stylish and beautiful.
Installation and configuration tutorial.