This chapter discusses a variety of functions that don't really fit neatly into existing categories, but that we felt were too important and useful to leave out of this book. Accordingly, we'll simply categorize them as "miscellaneous."
OverviewThis section contains functions for the following tasks:
constant() - Returning the value of a constant
define() - Defining a named constant
defined() - Checking whether a given named constant exists
die() - Outputting a message and terminating the current script
exit() - Terminating the current script
Evaluating strings as PHP code
eval() - Evaluating a string as PHP code
Retrieving information about the capabilities of a browser
get_browser() - Telling what the user's browser is capable of
Performing syntax highlighting for PHP
highlight_file() - Syntax highlighting of a file
highlight_string() - Syntax highlighting of a string
show_source() - Syntax highlighting of a file
iptcparse() - Parses a binary IPTC http://www.iptc.org/ block into single tags
leak() - Leaks memory
Delaying the execution of a script
sleep() - Delays execution
usleep() - Delays execution in microseconds
Configuring the Miscellaneous FunctionsNo configuration directives currently affect how the miscellaneous functions work.
Installing Miscellaneous Function SupportThe Miscellaneous functions are built into PHP by default. If desired, individual functions can be disabled in the php.ini file via the disable_functions directive.
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