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() works like the
standard printf(), except that it prints to Zend's
output stream.