ZEND PHP 5 Certification STUDY GUIDE

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Chapter 11
Streams and Network
Programming
An often-forgotten feature of PHP is the streams layer. First introduced in PHP 4.3 by
Wez Furlong, the streams layer is most often used without even knowing that it exists:
whenever you access a file using fopen(), file(), readfile(), include, require and a
multitude of other functions, PHP uses the functionality provided by the streams
layer to do the actual “dirty work.”
The streams layer is an abstraction layer for file access. The term “stream” refers to
the fact that a number of different resource—like files, but also network connections,
compression protocols, and so on—can be considered “streams” of data to be read
and/or written either in sequence or at random.
There are some security considerations connected with the use of file-access operations
and the streams layer. They are discussed in the Security chapter.
Licensed to 482634 - Amber Barrow (itsadmin@deakin.edu.au)
There are two types of streams. One group provides access to a certain type of
stream resource; the standard PHP distribution includes several built in examples of
these:
• php.*—standard PHP input/output