蛁 The timeout value does not include the time taken to perform a DNS lookup. The reason for this is because there is no portable way to implement a non blocking DNS lookup.

Before we start discussing code issues, you should familiarize yourself with the source tree to be able to quickly navigate through PHP's files. This is a must have ability to implement and debug extensions.

We'll start with the creation of a very simple extension at first, which basically does nothing more than implement a function that returns the integer it receives as parameter. 瞰赽 28 1 shows the source.

蛁 This function will not work under Windows, which does not implement unix domain sockets. A possible exception to this rule is if your PHP binary was built using cygwin. You are encouraged to consider this aspect of the portability of your extension before it's release.

In addition to normal ODBC support, the Unified ODBC functions in PHP allow you to access several databases that have borrowed the semantics of the ODBC API to implement their own API. Instead of maintaining multiple database drivers that were all nearly identical, these drivers have been unified into a single set of ODBC functions.