The internal debugger in PHP 3 is useful for tracking down
evasive bugs. The debugger works by connecting to a
TCP port for every time PHP 3 starts up.
All error messages from that request will be sent to this
TCP connection. This information is intended for
"debugging server" that can run inside an
IDE or programmable editor (such as Emacs).
How to set up the debugger:
Set up a TCP port for the debugger in the configuration file (debugger.port) and enable it
(debugger.enabled).
Set up a TCP listener on that port somewhere (for example
socket -l -s 1400 on Unix systems).
In your code, run
"debugger_on(host)", where
host is the IP number or name of the
host running the TCP listener.
Now, all warnings, notices etc. will show up on that listener
socket,
even if you turned them off with
error_reporting().
Debugging PHP