The Geospatial Data Abstraction Library ( GDAL ) is a computer software library for reading and writing raster and vector geospatial data formats (e.g. shapefile ), and is released under the permissive X/MIT style free software license by the Open Source Geospatial Foundation . As a library, it presents a single abstract data model to the calling application for all supported formats. It may also be built with a variety of useful command line interface utilities for data translation and processing. Projections and transformations are supported by the PROJ library.
46-600: The related OGR library (OGR Simple Features Library), which is part of the GDAL source tree , provides a similar ability for simple features vector graphics data. GDAL was developed mainly by Frank Warmerdam until the release of version 1.3.2, when maintenance was officially transferred to the GDAL/OGR Project Management Committee under the Open Source Geospatial Foundation . GDAL/OGR
92-631: A just-in-time (JIT) compiler. Because of the significant changes, the reworked Zend Engine was called Zend Engine 3 , succeeding Zend Engine 2 used in PHP ;5. Because of the major internal changes in phpng, it must receive a new major version number of PHP, rather than a minor PHP 5 release, according to PHP's release process. Major versions of PHP are allowed to break backward-compatibility of code and therefore PHP 7 presented an opportunity for other improvements beyond phpng that require backward-compatibility breaks. In particular, it involved
138-416: A repository is a data structure that stores metadata for a set of files or directory structure . Depending on whether the version control system in use is distributed, like Git or Mercurial , or centralized, like Subversion , CVS , or Perforce , the whole set of information in the repository may be duplicated on every user's system or may be maintained on a single server . Some of the metadata that
184-422: A minor release should occur which may include new features. Every minor release should at least be supported for two years with security and bug fixes, followed by at least one year of only security fixes, for a total of a three-year release process for every minor release. No new features, unless small and self-contained, are to be introduced into a minor release during the three-year release process. The mascot of
230-460: A new static return type, and a new mixed type. "Attributes", often referred to as "annotations" in other programming languages, were added in PHP 8, which allow metadata to be added to classes. throw was changed from being a statement to being an expression. This allows exceptions to be thrown in places that were not previously possible. PHP 8 includes changes to allow alternate, more concise, or more consistent syntaxes in
276-419: A number of scenarios. For example, the nullsafe operator is similar to the null coalescing operator ?? , but used when calling methods. The following code snippet will not throw an error if getBirthday() returns null: Constructor property promotion has been added as " syntactic sugar ," allowing class properties to be set automatically when parameters are passed into a class constructor . This reduces
322-455: A programming language [...] I just kept adding the next logical step on the way." A development team began to form and, after months of work and beta testing, officially released PHP/FI 2 in November 1997. The fact that PHP was not originally designed, but instead was developed organically has led to inconsistent naming of functions and inconsistent ordering of their parameters. In some cases,
368-490: A project. The repository keeps track of the files in the project, which is represented as a graph . A distributed version control system is made up of central and branch repositories . A central repository exists on the server. To make changes to it, a developer first works on a branch repository, and proceeds to commit the change to the former. A code forge is a web interface to a version control system. A user can commonly browse repositories and their constituent files on
414-429: A repository contains includes, among other things, a historical record of changes in the repository, a set of commit objects, and a set of references to commit objects, called heads . The main purpose of a repository is to store a set of files, as well as the history of changes made to those files. Exactly how each version control system handles storing those changes, however, differs greatly. For instance, Subversion in
460-572: Is a major version and has breaking changes from previous versions. New features and notable changes include: Just-in-time compilation is supported in PHP 8. PHP 8's JIT compiler can provide substantial performance improvements for some use cases, while (then PHP) developer Nikita Popov stated that the performance improvements for most websites will be less substantial than the upgrade from PHP 5 to PHP 7. Substantial improvements are expected more for mathematical-type operations than for common web-development use cases. Additionally,
506-537: Is an example of how PHP variables are declared and initialized. Unlike function and class names, variable names are case-sensitive. Both double-quoted ("") and heredoc strings provide the ability to interpolate a variable's value into the string. PHP treats newlines as whitespace in the manner of a free-form language , and statements are terminated by a semicolon. PHP has three types of comment syntax : /* */ marks block and inline comments; // or # are used for one-line comments. The echo statement
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#1733084855329552-532: Is considered a major free software project for its "extensive capabilities of data exchange" and also in the commercial GIS community due to its widespread use and comprehensive set of functionalities. Several software programs use the GDAL/OGR libraries to allow them to read and write multiple GIS formats. Such programs include: As of version 2.2.3, GDAL/OGR provides at least partial support for 154 raster and 93 vector geospatial data formats. A subset of data formats
598-700: Is no recommendation against the echo short tag <?= . Prior to PHP 5.4.0, this short syntax for echo only works with the short_open_tag configuration setting enabled, while for PHP 5.4.0 and later it is always available. The purpose of all these delimiters is to separate PHP code from non-PHP content, such as JavaScript code or HTML markup. So the shortest "Hello, World!" program written in PHP is: The first form of delimiters, <?php and ?> , in XHTML and other XML documents, creates correctly formed XML processing instructions. This means that
644-425: Is not processed by PHP, although the non-PHP text is still subject to control structures described in PHP code. The most common delimiters are <?php to open and ?> to close PHP sections. The shortened form <? also exists. This short delimiter makes script files less portable since support for them can be disabled in the local PHP configuration and it is therefore discouraged. Conversely, there
690-503: Is now no longer under development and nor are any security updates planned to be released. On 1 July 2004, PHP 5 was released, powered by the new Zend Engine II. PHP 5 included new features such as improved support for object-oriented programming , the PHP Data Objects (PDO) extension (which defines a lightweight and consistent interface for accessing databases), and numerous performance enhancements. In 2008, PHP 5 became
736-552: Is now produced by the PHP Group. PHP was originally an abbreviation of Personal Home Page , but it now stands for the recursive acronym PHP: Hypertext Preprocessor . PHP code is usually processed on a web server by a PHP interpreter implemented as a module , a daemon or a Common Gateway Interface (CGI) executable. On a web server, the result of the interpreted and executed PHP code—which may be any type of data, such as generated HTML or binary image data—would form
782-417: Is one of several facilities PHP provides to output text. In terms of keywords and language syntax, PHP is similar to C-style syntax. if conditions, for and while loops and function returns are similar in syntax to languages such as C, C++, C#, Java and Perl. PHP is loosely typed . It stores integers in a platform-dependent range, either as a 32, 64 or 128-bit signed integer equivalent to
828-455: Is supported to ensure the ability to directly create files and georeferencing them with the default GDAL compiling options. Here follows the list of data formats whose support is, by default, compiled to allow creation and georeferencing. GDAL supports a variety of vector data formats as seen here . It is extensible as well. Extensive capabilities of data exchange are essential for the daily GIS work. GRASS profits from an external project,
874-443: The random extension, which provides a pseudorandom number generator with an object-oriented API , Sensitive Parameter value redaction, and a ton of other features. PHP 8.3 was released on November 23, 2023. This release introduced readonly array properties, allowing arrays to be declared as immutable after initialization. It also added support for class aliases for built-in PHP classes, new methods for random float generation in
920-514: The C-language long type . Unsigned integers are converted to signed values in certain situations, which is different behaviour to many other programming languages. Integer variables can be assigned using decimal (positive and negative), octal , hexadecimal , and binary notations. Floating-point numbers are also stored in a platform-specific range. They can be specified using floating-point notation, or two forms of scientific notation . PHP has
966-653: The command line . The standard PHP interpreter, powered by the Zend Engine , is free software released under the PHP License . PHP has been widely ported and can be deployed on most web servers on a variety of operating systems and platforms . The PHP language has evolved without a written formal specification or standard, with the original implementation acting as the de facto standard that other implementations aimed to follow. W3Techs reports that as of 27 October 2024 (about two years since PHP 7
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#17330848553291012-604: The recursive acronym PHP: Hypertext Preprocessor . Afterwards, public testing of PHP 3 began, and the official launch came in June 1998. Suraski and Gutmans then started a new rewrite of PHP's core, producing the Zend Engine in 1999. They also founded Zend Technologies in Ramat Gan , Israel . On 22 May 2000, PHP 4, powered by the Zend Engine 1.0, was released. By August 2008, this branch had reached version 4.4.9. PHP 4
1058-647: The GDAL/OGR library < http://www.gdal.org >. This FOSS library is also used even by global data vendors as well as in some proprietary GIS applications. Many of the raster and vector formats supported for reading can be also be generated. In the words of Howard Butler, a director of the Open Source Geospatial Foundation, "I see GDAL as the glibc/glibc++ of the geospatial software world. It's open, it provides core functionality, I can't understand how anybody gets anything done without it." Source code repository In version control systems ,
1104-479: The JIT compiler provides the future potential to move some code from C to PHP, due to the performance improvements for some use cases. PHP 8 introduced the match expression. The match expression is conceptually similar to a switch statement and is more compact for some use cases. Because match is an expression, its result can be assigned to a variable or returned from a function. PHP 8 introduced union types,
1150-447: The PHP project is the elePHPant , a blue elephant with the PHP logo on its side, designed by Vincent Pontier in 1998. "The (PHP) letters were forming the shape of an elephant if viewed in a sideways angle." The elePHPant is sometimes differently coloured when in plush toy form. Many variations of this mascot have been made over the years. Only the elePHPants based on the original design by Vincent Pontier are considered official by
1196-518: The PHP source code or by using pre-built binaries. For PHP versions 5.3 and 5.4, the only available Microsoft Windows binary distributions were 32-bit IA-32 builds, requiring Windows 32-bit compatibility mode while using Internet Information Services (IIS) on a 64-bit Windows platform. PHP version 5.5 made the 64-bit x86-64 builds available for Microsoft Windows. Official security support for PHP 5.6 ended on 31 December 2018. PHP received mixed reviews due to lacking native Unicode support at
1242-475: The PHP 6 Unicode experiments had never been released, several articles and book titles referenced the PHP 6 names, which might have caused confusion if a new release were to reuse the name. After a vote, the name PHP 7 was chosen. The foundation of PHP 7 is a PHP branch that was originally dubbed PHP next generation ( phpng ). It was authored by Dmitry Stogov, Xinchen Hui and Nikita Popov, and aimed to optimize PHP performance by refactoring
1288-582: The Random extension, and enhanced PHP INI settings with fallback value support. Additionally, the new stream_context_set_options function provides improved API for stream manipulation, among other updates and deprecations. PHP 8.4 was released on November 21, 2024. Beginning on 28 June 2011, the PHP Development Team implemented a timeline for the release of new versions of PHP. Under this system, at least one release should occur every month. Once per year,
1334-481: The Version Control System instead of having to upload the file through a protocol like FTP . Examples of this kind of service include GitHub Pages and GitLab Pages . PHP PHP is a general-purpose scripting language geared towards web development . It was originally created by Danish-Canadian programmer Rasmus Lerdorf in 1993 and released in 1995. The PHP reference implementation
1380-411: The Zend Engine while retaining near-complete language compatibility. By 14 July 2014, WordPress -based benchmarks, which served as the main benchmark suite for the phpng project, showed an almost 100% increase in performance. Changes from phpng make it easier to improve performance in future versions, as more compact data structures and other changes are seen as better suited for a successful migration to
1426-420: The ability to embed HTML . By this point, the syntax had changed to resemble that of Perl , but was simpler, more limited, and less consistent. Early PHP was never intended to be a new programming language ; rather, it grew organically, with Lerdorf noting in retrospect: "I don't know how to stop it [...] there was never any intent to write a programming language [...] I have absolutely no idea how to write
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1472-472: The amount of boilerplate code that must be written. Other minor changes include support for use of ::class on objects, which serves as an alternative for the use of get_class() ; non-capturing catches in try-catch blocks; variable syntax tweaks to resolve inconsistencies; support for named arguments; and support for trailing commas in parameter lists, which adds consistency with support for trailing commas in other contexts, such as in arrays. PHP 8.1
1518-552: The community. These are collectable and some of them are extremely rare. The following "Hello, World!" program is written in PHP code embedded in an HTML document: However, as no requirement exists for PHP code to be embedded in HTML, the simplest version of Hello, World! may be written like this, with the closing tag ?> omitted as preferred in files containing pure PHP code. The PHP interpreter only executes PHP code within its delimiters . Anything outside of its delimiters
1564-469: The core language level. In 2005, a project headed by Andrei Zmievski was initiated to bring native Unicode support throughout PHP, by embedding the International Components for Unicode (ICU) library, and representing text strings as UTF-16 internally. Since this would cause major changes both to the internals of the language and to user code, it was planned to release this as version 6.0 of
1610-476: The early PHP syntax : PHP/FI could be used to build simple, dynamic web applications . To accelerate bug reporting and improve the code, Lerdorf initially announced the release of PHP/FI as "Personal Home Page Tools (PHP Tools) version 1.0" on the Usenet discussion group comp.infosystems.www.authoring.cgi on 8 June 1995. This release included basic functionality such as Perl-like variables , form handling, and
1656-431: The following changes: PHP 7 also included new language features. Most notably, it introduced return type declarations for functions which complement the existing parameter type declarations, and support for the scalar types (integer, float, string, and boolean) in parameter and return type declarations. PHP 8 was released on 26 November 2020, and is currently the second-most used PHP major version. PHP 8
1702-408: The function names were chosen to match the lower-level libraries which PHP was "wrapping", while in some very early versions of PHP the length of the function names was used internally as a hash function , so names were chosen to improve the distribution of hash values . Zeev Suraski and Andi Gutmans rewrote the parser in 1997 and formed the base of PHP 3, changing the language's name to
1748-432: The language, along with other major features then in development. However, a shortage of developers who understood the necessary changes, and performance problems arising from conversion to and from UTF-16, which is rarely used in a web context, led to delays in the project. As a result, a PHP 5.3 release was created in 2009, with many non-Unicode features back-ported from PHP 6, notably namespaces. In March 2010,
1794-568: The only stable version under development. Late static binding had been missing from previous versions of PHP, and was added in version 5.3. Many high-profile open-source projects ceased to support PHP 4 in new code from February 5, 2008, because of the GoPHP5 initiative, provided by a consortium of PHP developers promoting the transition from PHP 4 to PHP 5. Over time, PHP interpreters became available on most existing 32-bit and 64-bit operating systems, either by building them from
1840-508: The page itself. While forges are mainly used to perform version control operations, some forges allow users to host static web pages by uploading its source code (such as HTML and JavaScript , but not PHP ) to a repository. This is usually done in order to provide documentation or a landing page for a software project. The use of repositories as a place to upload web documents allows version control to be integrated, and additionally allows quick iteration because changes are pushed through
1886-414: The past relied on a database instance but has since moved to storing its changes directly on the filesystem. These differences in storage techniques have generally led to diverse uses of version control by different groups, depending on their needs. In software engineering, a version control system is used to keep track of versions of a set of files, usually to allow multiple developers to collaborate on
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1932-473: The project in its current form was officially abandoned, and a PHP 5.4 release was prepared to contain most remaining non-Unicode features from PHP 6, such as traits and closure re-binding. Initial hopes were that a new plan would be formed for Unicode integration, but by 2014 none had been adopted. During 2014 and 2015, a new major PHP version was developed, PHP 7. The numbering of this version involved some debate among internal developers. While
1978-497: The resulting mixture of PHP code and other markups in the server-side file is itself well-formed XML. Variables are prefixed with a dollar symbol , and a type does not need to be specified in advance. PHP 5 introduced type declarations that allow functions to force their parameters to be objects of a specific class, arrays, interfaces or callback functions . However, before PHP 7, type declarations could not be used with scalar types such as integers or strings. Below
2024-409: The whole or part of an HTTP response. Various web template systems , web content management systems , and web frameworks exist that can be employed to orchestrate or facilitate the generation of that response. Additionally, PHP can be used for many programming tasks outside the web context, such as standalone graphical applications and drone control. PHP code can also be directly executed from
2070-738: Was discontinued and 11 months after the PHP 8.3 release), PHP 7 is still used by 50.0% of PHP websites, which is outdated and known to be insecure. In addition the even more outdated (discontinued for 5+ years) and insecure PHP 5 is used by 13.2% and the no longer supported PHP 8.0 is also very popular. Meaning the vast majority do not use the supported versions. PHP development began in 1993 when Rasmus Lerdorf wrote several Common Gateway Interface (CGI) programs in C , which he used to maintain his personal homepage . He extended them to work with web forms and to communicate with databases , and called this implementation "Personal Home Page/Forms Interpreter" or PHP/FI. An example of
2116-502: Was released on November 25, 2021. It added support for enumerations (also called "enums"), declaring properties as readonly (which prevents modification of the property after initialization), and array unpacking with string keys. The new never type can be used to indicate that a function does not return. PHP 8.2 was released on December 8, 2022. New in this release are readonly classes (whose instance properties are implicitly readonly), disjunctive normal form (DNF) types, and
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