A function is a group of statements that can be executed any time you want.
PHP has a number of predefine functions for you to use.
Below given are the different type of funtions available in PHP
It can be considered as a flag that controls how you access form, server, and environment variables. By default this variable is set to Off, requiring you to use special arrays to access these variables. Its values are set in php.ini file .When the value is set to “on” , PHP will dynamically create global variable for many server variable as well as the query string parameters .
Its always better to set the value as “off”
Magic quotes is a controversial feature of the PHP scripting language, which was introduced to help newcomers write functioning SQL commands without requiring manual escaping. It was later described and widely misinterpreted as help to prevent inexperienced developers from writing code which is vulnerable to SQL injection attacks. This feature is officially deprecated as of PHP 5.3.0, and removed in PHP 5.4 due to security concerns
Safe mode is a diagnostic mode of a computer operating system (OS). It can also refer to a mode of operation by application software. Safe mode is intended to fix most, if not all problems within an operating system. It is also widely used for removing Rogue security software.
Simple XML is a variation of XML containing only elements. All attributes are converted into elements. Not having attributes or other xml elements such as the XML declaration / DTDs allows the use of simple and fast parsers. This format is also compatible with mainstream XML parsers.
PDO_MYSQL is a driver that implements the PHP Data Objects (PDO) interface to enable access from PHP to MySQL
The PHP Data Objects (PDO) extension defines a lightweight, consistent interface for accessing databases in PHP.
Features
Perl Compatible Regular Expressions (PCRE) is a regular expression C library inspired by Perl’s external interface, written by Philip Hazel. PCRE’s syntax is much more powerful and flexible than either of the POSIX regular expression flavors and many classic regular expression libraries. The name is misleading, because PCRE is Perl-compatible only if you consider a subset of PCRE’s settings and a subset of Perl’s regular expression facilities.
The PCRE library is incorporated into a number of prominent open-source programs, such as the Apache HTTP Server and the PHP and R scripting languages; and can be incorporated in proprietary software too (BSD license). As of Perl 5.10, PCRE is also available as a replacement for Perl’s default regular expression engine through the re::engine::PCRE module.
mcrypt is a replacement for the popular UNIX crypt command. crypt was a file encryption tool that used an algorithm very close to the World War II enigma cipher, which was broken. Mcrypt provides the same functionality but uses several modern algorithms such as AES. Libmcrypt, Mcrypt’s companion, is a library of code which contains the actual encryption functions and provides an easy method for use.
Pramod T P 