The Art of Debugging: From STRDBG to RDP. Charles Guarino. Copyright Central Park Data Systems, Inc. 2

Transcription

1 The Art of Debugging: From STRDBG to RDP Charles Guarino Central Park Data Systems, Inc. Copyright Central Park Data Systems, Inc. 1 About the presenter: With an IT career spanning over 25 years, Charles Guarino has been a consultant for most of them. Since 1995 he has been founder and President of Central Park Data Systems, Inc., a Long Island based IBM midrange consulting company. He has published several technical and strategic articles for the IT community and has served as a member of a technical publication s Editorial Review Board. He was inducted into COMMON s Speaker Excellence Hall of Fame in 2008 and also selected as one of LISTnet's Long Island s Twenty Top Techies for Charles is currently a COMMON Application Development Subject Matter Expert and a Board Member and monthly Q&A host of LISUG, a Long Island IBM System i User s Group. Charles can be reached at cguarino@centralparkdata.com Copyright Central Park Data Systems, Inc. 2 1

2 Many of the techniques discussed here require *PGMR authority or higher. I encourage you to learn more about commands you are not familiar with before attempting to use them! Legal disclaimer, brought to you by my attorney! Copyright Central Park Data Systems, Inc. 3 New Terms, Concepts and Agenda Perspectives Service Entry Point Debug Server Debug Configurations Views Debugging your own program Debugging another user s programs LIVE DEMONSTRATION! Copyright Central Park Data Systems, Inc. 4 2

3 New Terms and Concepts Perspective: Groups common tasks to facilitate development and testing Copyright Central Park Data Systems, Inc. 5 Basic RPG Program Flow Start program *INZSR Read all records and blank out existing encrypted values, then reset pointer Read a record from file CUSTMAST If %EOF, leave program loop and exit program Call encryption service program, return ciphertext Update CUSTMAST with encrypted data Read more records from file CUSTMAST Copyright Central Park Data Systems, Inc. 6 3

4 Program we will be debugging Copyright Central Park Data Systems, Inc. 7 There are TWO methods to start the debugger: 1) Launching the debugger directly from RDP (with or without parameter prompting) 2) Service Entry Point (S.E.P.). When the program is run anywhere with the given parameters, the debugger will start. Copyright Central Park Data Systems, Inc. 8 4

5 Starting to debug Method 1: Calling program object Copyright Central Park Data Systems, Inc. 9 Method 2: Using a Service Entry Point or SEP Copyright Central Park Data Systems, Inc. 10 5

6 Need to start the IBM i Debug Server! Can start through RDi or a green screen command. ) 1) - OR - 2) Copyright Central Park Data Systems, Inc. 11 The Debug Server: The debug server runs in subsystems QSYSWRK and QUSRWRK, as jobs Q5BROUTE and Q5BROUTER, respectively. Only needs to be started once. Will service ALL requests for ALL users. Recommendation start the Debug Server in your system startup job! Use command STRDBGSVR. Copyright Central Park Data Systems, Inc. 12 6

7 DEBUGGING WITH A PROMPT Copyright Central Park Data Systems, Inc. 13 DEBUG CONFIGURATION CAN BE NAMED AND SAVED SPECIFY WHAT AND HOW TO RUN CAN SPECIFY PROGRAM PARAMETERS Copyright Central Park Data Systems, Inc. 14 7

8 LAUNCHING AN EXISTING CONFIGURATION Copyright Central Park Data Systems, Inc. 15 Debug perspective: A first look using default settings Copyright Central Park Data Systems, Inc. 16 8

9 Introducing the Debug View Copyright Central Park Data Systems, Inc. 17 Introducing the VARIABLES View Copyright Central Park Data Systems, Inc. 18 9

10 Introducing the MONITORS view YOU decide what appears in this view. Useful when watching a specific set of fields Copyright Central Park Data Systems, Inc. 19 Introducing the BREAKPOINTS view Breakpoints can be set at the source level or at runtime Breakpoints can be conditional or unconditonal Watch breakpoints are set at runtime Here we re watching variable direction Copyright Central Park Data Systems, Inc

11 Adding a breakpoint Copyright Central Park Data Systems, Inc. 21 Setting a WATCH breakpoint Copyright Central Park Data Systems, Inc

12 Watching for the field named direction Copyright Central Park Data Systems, Inc. 23 Copyright Central Park Data Systems, Inc

13 The OUTLINE view is INVALUABLE when debugging a program Copyright Central Park Data Systems, Inc. 25 LET S GET STARTED! Shortcuts, current line of execution, pre-assigned breakpoint F6 to STEP, F8 to RESUME Copyright Central Park Data Systems, Inc

14 Introducing the PROGRAMS view Functionally similar to pressing F14 in DSPMODSRC screen Copyright Central Park Data Systems, Inc. 27 HOVERING! Place the cursor over a field on its value appears. Must easier than typing ev cleardata or pressing F11! Copyright Central Park Data Systems, Inc

15 SERVICE ENTRY POINTS Copyright Central Park Data Systems, Inc. 29 THIS IS FUNCTIONALLY SIMILAR TO STRSRVJOB Copyright Central Park Data Systems, Inc

16 The next time user CHARLIE calls program ENCDEBUG the debugger will wake up and wait for programmer s input. Copyright Central Park Data Systems, Inc. 31 DEBUGGING ANOTHER USER S ACTIVE JOB Copyright Central Park Data Systems, Inc

17 What we covered today: New terms and concepts Perspectives Debug Server Service Entry Points Using the Debug Perspective Setting up breakpoints Setting Watch Breakpoints Using Different Views Hovering Over Variables Debug Configurations Debugging Another User s Job Copyright Central Park Data Systems, Inc. 33 Thank You!!!!! The Art of Debugging: From STRDBG to RDP Charles Guarino cguarino@centralparkdata.com Copyright Central Park Data Systems, Inc