The Debug Dance - An Intro To Step Debugging - Chicago PHP UG

This talk was presented at the Chicago PHP UG meetup on March 27th, 2017: https://www.meetup.com/Chicago-PHP-User-Group/events/237220317/

Transcript

1. Sammy Kaye Powers
   An Intro To
   Step Debugging in
   Dance
   The
   Chicago PHP UG
   March 27th, 2017
   

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2. Does not work for
   

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3. What is
   Debugging?
   Finding and fixing of unexpected behavior in code
   

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4. So you write
   Some Code
   

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5. Does not work
   

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6. You could check the
   Error logs
   

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7. All the things
   var_dump()
   

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9. OR
   

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10. Use a
    ‘er
    

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11. Kate Gregory “ I'm not saying, ‘don't
    use printf()’, [...] but
    I think it's insane to
    use printf() on day
    one of learning C++.
    [...] I would first say
    use the debugger.
    Episode 30: Stop Teaching C
    (When Teaching C++)
    

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12. …now is the perfect time to learn
    Step Debugging
    BNEW!
    Professional
    

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13. Some step-debugging
    Jargon
    

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14. a signal that tells the debugger to pause the execution of your code
    Breakpoint
    

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15. run to the next breakpoint
    Resume Program
    

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16. if the next line is a function call, enter the function
    Step Into
    

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17. run to the end of the current function
    Step Out
    

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18. advance to the next line in the same scope
    Step Over
    

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19. a live portal into the code execution process
    Debugging Console
    

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20. shows the execution path to the point where the code was paused
    Frames
    I… don’t have a cool drawing for “frames”…
    

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21. &
    Environment
    Setup
    

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22. Setup
    

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23. #1
    Start listening to
    debugging connections
    

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24. #2
    Set a
    Breakpoint
    

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25. Done!
    

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26. Setup
    

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27. configured
    installed
    installed
    

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28. $ brew tap homebrew/homebrew-php
    $ brew install php71
    $ brew install php71-xdebug
    on
    Homebrew
    Install +
    

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29. $ add-apt-repository -y ppa:ondrej/php
    $ apt-get update
    $ apt-get install php7.1-xdebug
    on
    APT
    Install +
    

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30. https://xdebug.org/docs/install
    Install +
    

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32. Configure
    

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33. $ php --ini
    

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34. $ sudo vi /usr/local/etc/php/
    7.1/conf.d/ext-xdebug.ini
    

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35. $ php -i | grep xdebug
    

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36. Start a session
    or
    CLI
    

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37. Query Param
    XDEBUG_SESSION_START
    

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38. Cookie
    XDEBUG_SESSION
    

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42. Env Variable
    export XDEBUG_CONFIG="idekey=foo"
    CLI
    

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43. Env Variable
    set XDEBUG_CONFIG="idekey=foo"
    CLI
    

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44. Don’t forget to unset
    set XDEBUG_CONFIG=
    unset XDEBUG_CONFIG
    when you’re done
    

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45. Run some code!
    &
    CLI
    

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46. PHP’s Built-in
    Web Server
    run locally using
    

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47. Built right into the CLI SAPI!
    $ php -S 127.0.0.1:8888
    

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48. But!
    if we have time, we’ll also use
    &
    

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