Debugging code is an essential task for every software developer. PHP is one of the most popular programming languages, but setting up debugging for PHP applications may be tricky. This session will demonstrate what debugging technologies and tools are available for PHP. How to debug CLI scripts, Web apps and REST services. What's the easiest way to set up debugging for the different server environments: local, remote, cloud or virtualized; in development or in production.

1. Essential Debugging
PHP Debugging techniques, tips & tricks
Kaloyan Raev
Zend / Rogue Wave

2. $ whoami
Zend Studio Team Lead
Eclipse Committer
Live in Sofia, Bulgaria
Skier

3. Why Debugging?
Because we make bugs
Because we want to fix them!

4. Debugging in PHP 101
echo $myvar;
var_dump ( $myvar );
die ( "Unexpected value in myvar: $myvar" );
error_reporting ( E_ALL );

5. Better Way?
Use a debugger!

6. Breakpoints
$left == 10

7. Stack Traces

8. Variables Overview

9. Fine Execution Control

10. Changes in Last Step

11. In-Editor Inspections
Shift + Ctrl + I

12. Watched Expressions

13. Multiple Sessions

14. PHP Debugger Engines
Xdebug
Zend Debugger
phpdbg

15. Xdebug Zend Debugger phpdbg
Built-in PHP ✅
Communication protocol
DBGp
XML-based
binary
PHP-specific
own
XML-based
Available in PHP 7 (as of today) ✅
IDE Support ✅ ✅
Remote Debugging ✅ ✅ ✅
Profiling ✅ ✅

16. The Easiest Way for Setting Up PHP with Debugger
Out of the box!
v8.5 provides both Xdebug and Zend Debugger

18. Docker Containers
tommylau/xdebug - Apache + PHP + Xdebug
Tutorial: Debugging PHP Web Apps in a Docker Container

19. Just CLI Scripts
Zend Studio bundles PHP binaries with Zend Debugger included

20. No IDEs Please
phpdbg is for you
Built-in PHP since 5.6
as SAPI module
CLI user interface

21. Do It Yourself Stack
Instructions for Zend Debugger
Instructions for Xdebug
Instructions for phpdbg

22. Browser Toolbars
Xdebug
Zend Debugger
Browser
Toolbar
Debug
Engine
IDE
1. R
equest w
ith
debug
cookie
1. Request broadcast port
2.O
pen
debug
session
4.O
pen
debug
session
2. Response with debug info
3. R
equest

23. Xdebug Toolbars
Chrome
➢ Xdebug helper
➢ Xdebug enabler
Firefox
➢ The easiest Xdebug
➢ easy Xdebug
Opera
➢ Xdebug
➢ Xdebug launcher
Safari
➢ Xdebug Toggler

24. Zend Debugger Toolbars
Chrome
➢ zDebug
Firefox
➢ Zend Firefox Toolbar
Internet Explorer
➢ Zend Internet Explorer Toolbar

25. Z-Ray

26. Z-Ray Live!

28. Remote Debugging
Intranet
Direct Internet Connection
Firewall / Proxy
➢ SSH Tunneling - works for both Xdebug and Zend Debugger
➢ Zend Debugger Tunneling - easier to setup, does not require Zend Server

29. Debug Mode
Every request to server triggers a new debug session in IDE
Useful for debugging requests from mobile apps
Available only for Zend Debugger in Zend Server

30. Thank you!
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