Chapter 36. Printing Information
Often it's necessary to print messages to the output stream from your module, just as print() would be used within a script. PHP offers functions for most generic tasks, such as printing warning messages, generating output for phpinfo(), and so on. The following sections provide more details. Examples of these functions can be found on the CD-ROM.
zend_printf()
zend_printf() works like the standard printf(), except that it prints to Zend's output stream.