PHP

Information and howto articles for PHP

PHP is a powerful open source server-sided scripting language that can be used on a wide variety of operating systems and webservers, including Apache on UNIX and IIS on Windows.

PHP contains numerous extensions which enable you to dynamically create images and flash files, parse xml, connect to remote servers using pop, imap, ftp, http and raw sockets, natively access many database servers including PostgreSql, MySQL and Microsoft SQL Server, compress and decompress files, lookup domain names and and much more.

PHP has an excellent manual and online documentation which covers every function for every extension available.

PHP Error Class ‘XsltProcessor’ not found

If you get the following error message in PHP then it means you need to have the XSL extension installed. Obviously the /path/to/file.php will be the actual path and filename of the PHP script the error occured in, and the line number will be the actual line. The PHP manual says that "PHP 5 includes the XSL extension by default" but one of my CentOS 5 installations it didn’t seem to be; the following post looks at how to install this extension on CentOS 5.

Fatal error: Class 'XsltProcessor' not found in /path/to/file.php on line 138

Javascript and CSS file timestamps with PHP

Many websites I have worked on have frequently modified CSS style sheets and Javascript library files. In order to prevent Javascript errors or layout and style issues caused by web browsers caching these files, I used to rename the file for each revision, and then modify the name of the CSS or JS file in my PHP header include files. This article looks out how I now do this using the modified timestamp of the file.

Create a file with a unique name with PHP

The PHP function tempnam() creates a file with a unique name. This can be useful if you need to output some data into a temporary file for one reason or another, and the actual name of the file is not important.

Install the MSSQL module for PHP on CentOS 5

Unfortunately there is no pre-built module/extension for MSSQL for PHP in the Yum repositories for CentOS 5, so you need to build it yourself. It’s a reasonably simple process, but you do need to have gcc and php-devel packages already installed (and a whole bunch of others which I’ll list at the end of this post).

Determine whether PHP is being run via HTTP or CLI

PHP can be run as a webserver module, as a CGI application or from the command line as a CLI script. There is both a function and a PHP constant which allows you to determine whether PHP is being run via HTTP or CLI. This post looks at the function and constant and the possible values, as determined in the PHP 5.2.5 source code.

Correcting the PHP timezone

The end of daylight savings in New Zealand has been changed from Sunday March 16th (today) to Sunday April 6th. Last week I looked out how to check the daylight savings dates will be applied correctly on Linux, but now that it’s actually the day itself it turns out that while the operating system is using the correct date, PHP is not due to PHP5 maintainin its own internal timezone database. This post looks at how to temporarily correct the solution until it’s fixed in the distro’s PHP builds.