Building Query Strings in PHP Query strings are not limited to form data. Query string is simply a string of characters stored in a URL, a user can manually create a URL containing a query string in the PHP script, and then include the URL as a link within the displayed page or in an …
Accessing Data in Query Strings in PHP To access the field names and values in a query string you simply use the $_GET superglobal array function. Syntax $firstName = $_GET[“firstName”]; Example Here, we will illustrate an example which displays a sequence of Square numbers. Save the script as number_squaring.php in the document root folder, and run it …
Working with Cookies in PHP Cookies allow users to store a small amount of data, not more than 4KB within the user’s browser itself. Then, whenever the browser requests a page on the Web site, all the data in the cookie is automatically sent to the server within the request. This means that when a …
Cookie Components in PHP A cookie is sent from the server to the browser as part of the HTTP headers. Here we will illustrate an example of an HTTP header to create a cookie: Set-Cookie: fontSize=3; expires=saturday, 9-May-2015 17:53:08 GMT; path=/; domain=.example.com; HttpOnly Here, we will describe you all the information contained in the cookie. …
Setting a Cookie in PHP PHP provides a built – in function, setcookie() , that can send the appropriate HTTP header to create the cookie on the browser. Here, you will learn how to set a cookie. You should always call setcookie() before sending any output to the browser. This is because setcookie() needs to …
Accessing Cookies Scripts In PHP To Access cookies in PHP is very easy: A user can simply read values from the $_COOKIE superglobal array. To display the pageViews cookie set use : echo $_COOKIE[“pageViews”]; // Displays “8” As with $_GET and $_POST , in a real – world situation you should not directly output data …
Removing Cookies In PHP If a user no longer needs a cookie that is stored on the user’s browser, then a user can instruct the browser to delete it. To delete a cookie, a user has to call setcookie() with the cookie name and any value (such as an empty string), and pass in an …
Although cookies are a useful way to store data but they have some problems like Firstly, they are not very secure. As with form data and query strings, an attacker can easily modify a cookie’s contents to insert data that could potentially break the application or compromise security. Secondly, a user can store a fair …
PHP Session new session, this function generates a unique SID for the session and sends it to the browser as a cookie called PHPSESSID (by default). However, if the browser has sent a PHPSESSID cookie to the server because a session already exists, session_start() uses this existing session: session_start();
Working with session data in PHP is also simple. A user can store all the session data as keys and values in the $_SESSION[] superglobal array. So a user might store the user’s first name using: $_SESSION[“firstName”] = “Aman”; Then display the user’s first name in the same page request or during a later request …
As earlier you have read that by default PHP sessions are automatically deleted when users quit their browser, because the PHPSESSID cookie ’ s expires field is set to zero. However, sometimes a user might want to destroy a session immediately. For example, if a shopper has checked out and placed an order via your …
A session is a logical object created by the PHP engine to allow you to preserve data across subsequent HTTP requests. Cookies are a way for the server to store the information on the user’s machine so that it can remember the user. Each time the same computer requests a page with a browser, it …
Everything on your hard drive is stored as a file. There are ordinary program files, data files, files that are directories, and special files that help the hard drive keep track of the contents of folders and files. PHP has functions that can work with any file type, but basically work with text files that …
If you want to work with a file from within the PHP script, then you first need to open the file. So when you open a file, you create a file handle. A file handle is a pointer associated with the open file that you can then use to access the file’s contents. When you …
Here, you will learn how to read and write data in a file. There are various functions described here. Function Descriptions fread() This function is used to Read a string of characters from a file. fwrite() This function is used to Write a string of characters to a file. fgetc() This function is used to …
File system permissions determine what different users can do with each file and directory in the file system. For example, whereas one user might have permission to read and write to a file, another user may only be allowed to read the file. A third user might not even be allowed to do that. Permissions …
PHP also allows you to copy, rename, and delete files. The functions to perform these operations are copy() , rename() , and unlink() , respectively. The copy() function takes two string arguments: the first argument is the path to the file to copy, and the second argument is the path to copy it to. It …
Regular expression provides a special syntax for searching for patterns of text within strings. A regular expression is simply a string of search text. Regular expressions are included by delimiters (usually slashes). For example, this simple regular expression searches for the word “ csitquestion ” anywhere within the target string: /csitquestion/ Regular expressions start to become …
PHP’s main pattern matching function is preg_match() . This function takes the following arguments: The regular expression to search for (as a string) The string to search through An optional array to store any matched text in. An optional integer specifying any flags for the match operation. Currently only one flag is supported: PREG_OFFSET_CAPTURE . …
Here, you will learn how to replace the text from a string. In simple words, you can say that you need to replace a portion of a string with new text. Simple search – and – replace functions like str_replace() are useful for replacing literal strings. However, if you need to replace more complex patterns …