Kernighan and Pike on debugging

While reading the log4j manual, I came across this excellent quote from Brian W. Kernighan and Rob Pike’s “The Practice of Programming”:

As personal choice, we tend not to use debuggers beyond getting a stack trace or the value of a variable or two. One reason is that it is easy to get lost in details of complicated data structures and control flow; we find stepping through a program less productive than thinking harder and adding output statements and self-checking code at critical places. Clicking over statements takes longer than scanning the output of judiciously-placed displays. It takes less time to decide where to put print statements than to single-step to the critical section of code, even assuming we know where that is. More important, debugging statements stay with the program; debugging sessions are transient.

+1 to that.

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  1. Posted January 8, 2007 at 20:53 | Permalink

    +1 to that from me as well. I agree 100% :)

  2. Posted January 10, 2007 at 11:46 | Permalink

    Neither of you write much C lately, I suspect …

    I find I use debuggers more when dealing with other people’s code, people who aren’t to hand and whose thought processes I don’t necessarily get.

  3. Michael Sander
    Posted January 12, 2007 at 01:42 | Permalink

    What is needed is a debugger that puts printf’s everywhere. A debugger where you can step backwards and check out the programs state after it executed. Such debuggers exist… check em out: TimeMachine: C/C++ Amber: C/C++ (Still in development) OmniCore: Java – There are plenty of others too!

  4. a
    Posted October 15, 2010 at 19:44 | Permalink

    that was written before eclipse. it doesn’t apply today if you’re using java or other programming language for which eclipse’s (or vs’s) visual debugger is fully integrated.