3 ms·

>As someone who only used IDE debuggers all his (short) programming career, I was wondering, how do you debug without a visual debugger? I'd ask the reverse of

>As someone who only used IDE debuggers all his (short) programming career, I was wondering, how do you debug without a visual debugger? I'd ask the reverse of you. Why do you spend time in a debugger at all? For 99% of the bugs logical thinking and a few printfs work faster and better ran blindly running around setting breakpoints and examining values.

stevvooe 14y ago
Even then, Gdb kills many competitors on flexibility alone.
kamaal 14y ago
This is something I have always wondered about. Though learning how to use the debugger is a good skill to learn, these days I don't know anyone around me who has ever used a debugger, or even finds a use for it. I think the best tools of our age are really REPL's, which allows you to test out your guesses/hypothesis in the form of snippets. Personally I have probably used a debugger 5-6 times in my whole programming career, these days I hardly find a use for it. On the other hand, I find tools like these very useful: https://metacpan.org/module/Devel::NYTProf https://metacpan.org/module/Devel::NYTProf
- marcusf 14y ago
  Depends on your use case. If you're trying to find an issue in Java code running on an app server somewhere where you're not allowed to update code (say, if you work in B2B and it's a customer site), being able to remote debug does wonders.
venomsnake 14y ago
Hmm ... a few cases i could think of. Memory stomp bugs. Race conditions. And some Entrprise OO problems - inspecting 260 layer stacktrace and exploring very complicated structures.
dagw 14y ago
Debuggers are handy for the last 1% of bugs. And anyway there is nothing about debuggers that precludes logical thinking or requires "blindly" placing breakpoints.
veidr 14y ago
Adding printf statements implies recompiling or rerunning code. A good debugger lets you set breakpoints against your app while it runs, and have the breakpoint log a message instead. So even if you just want to log messages at certain spots, a good debugger works better (to say nothing of following program execution through long sequences of source code files, which is even handier when the source code is some open source component that you didn't write). I agree that printf works better than "blindly running around setting breakpoints", but so does pounding a 12-pack of beer and then hitting yourself in the face with a mallet until the solution comes to you. On the other hand, learning to use a modern, advanced debugger and then applying that skill along with some of that logical thinking can be extremely effective in finding the cause of bugs as quickly as possible. For languages like Objective-C or Java, I think the 'real men don't need a debugger bro' attitude is nuts. It is different for a lot of newer and/or more dynamic programming languages, which simply don't have debuggers anywhere close to as powerful as those of IntelliJ or Xcode/lldb.
wingerlang 14y ago
It can be nice to pause the execution and think, then continue one line at the time and really see what is happening. Also I hate writing prints over and over. Sometimes it is imply faster to put a breakpoint, look at the value and then pop it away. As opposed to manually writing the print, then check, and then removing it. Thats just my opinion though.
sanswork 14y ago
Because printfs and their like have been know to change the running conditions of an application causing or masking bugs. Once you learn how to use a debugger properly it is infinitely better than printfs.
- baudehlo 14y ago
  I think it very much depends on the language and platform/environment. I've been programming professionally for nearly 20 years, in languages ranging from Perl to C/C++ to Javascript, and the only times I've used GDB in the last 15 years have been when C/C++ code is segfaulting and I want a stack trace. The rest of the time I use print/printf statements. I've built some pretty successful software this way, some of which you've probably heard of or used. On the other hand if I were coding exclusively in C/C++, or Java, or using an IDE for my work, I might use a debugger more.
  - sanswork 14y ago
    I think the use of the word printf makes which ones we're discussing pretty clear. I'm getting up there too. And I know lots of older programmers with very bad habits. Many who have also working on household names. Age+popularity != skill/quality. Doing that in anything but interpreted and micro applications seems like a massive waste of time and effort(both placing the printfs, recompiling, removing them recompiling. We've all done it. It doesn't mean its a good way to do it. And like I said above it can introduce bugs into your code doing so. I remember one case where a printf for debugging changed the memory in such a way as to make an uninitialized variable work. After testing when the printfs were removed the application would stop working. Introducing code into your code base with the intention of removing it later when there is an easy way to not do so is asking for trouble.

stevvooe 14y ago

Even then, Gdb kills many competitors on flexibility alone.

kamaal 14y ago

This is something I have always wondered about. Though learning how to use the debugger is a good skill to learn, these days I don't know anyone around me who has ever used a debugger, or even finds a use for it. I think the best tools of our age are really REPL's, which allows you to test out your guesses/hypothesis in the form of snippets. Personally I have probably used a debugger 5-6 times in my whole programming career, these days I hardly find a use for it. On the other hand, I find tools like these very useful: https://metacpan.org/module/Devel::NYTProf https://metacpan.org/module/Devel::NYTProf

marcusf 14y ago
Depends on your use case. If you're trying to find an issue in Java code running on an app server somewhere where you're not allowed to update code (say, if you work in B2B and it's a customer site), being able to remote debug does wonders.

venomsnake 14y ago

Hmm ... a few cases i could think of. Memory stomp bugs. Race conditions. And some Entrprise OO problems - inspecting 260 layer stacktrace and exploring very complicated structures.

dagw 14y ago

Debuggers are handy for the last 1% of bugs. And anyway there is nothing about debuggers that precludes logical thinking or requires "blindly" placing breakpoints.

veidr 14y ago

Adding printf statements implies recompiling or rerunning code. A good debugger lets you set breakpoints against your app while it runs, and have the breakpoint log a message instead. So even if you just want to log messages at certain spots, a good debugger works better (to say nothing of following program execution through long sequences of source code files, which is even handier when the source code is some open source component that you didn't write). I agree that printf works better than "blindly running around setting breakpoints", but so does pounding a 12-pack of beer and then hitting yourself in the face with a mallet until the solution comes to you. On the other hand, learning to use a modern, advanced debugger and then applying that skill along with some of that logical thinking can be extremely effective in finding the cause of bugs as quickly as possible. For languages like Objective-C or Java, I think the 'real men don't need a debugger bro' attitude is nuts. It is different for a lot of newer and/or more dynamic programming languages, which simply don't have debuggers anywhere close to as powerful as those of IntelliJ or Xcode/lldb.

wingerlang 14y ago

It can be nice to pause the execution and think, then continue one line at the time and really see what is happening. Also I hate writing prints over and over. Sometimes it is imply faster to put a breakpoint, look at the value and then pop it away. As opposed to manually writing the print, then check, and then removing it. Thats just my opinion though.

sanswork 14y ago

Because printfs and their like have been know to change the running conditions of an application causing or masking bugs. Once you learn how to use a debugger properly it is infinitely better than printfs.

baudehlo 14y ago
I think it very much depends on the language and platform/environment. I've been programming professionally for nearly 20 years, in languages ranging from Perl to C/C++ to Javascript, and the only times I've used GDB in the last 15 years have been when C/C++ code is segfaulting and I want a stack trace. The rest of the time I use print/printf statements. I've built some pretty successful software this way, some of which you've probably heard of or used. On the other hand if I were coding exclusively in C/C++, or Java, or using an IDE for my work, I might use a debugger more.
- sanswork 14y ago
  I think the use of the word printf makes which ones we're discussing pretty clear. I'm getting up there too. And I know lots of older programmers with very bad habits. Many who have also working on household names. Age+popularity != skill/quality. Doing that in anything but interpreted and micro applications seems like a massive waste of time and effort(both placing the printfs, recompiling, removing them recompiling. We've all done it. It doesn't mean its a good way to do it. And like I said above it can introduce bugs into your code doing so. I remember one case where a printf for debugging changed the memory in such a way as to make an uninitialized variable work. After testing when the printfs were removed the application would stop working. Introducing code into your code base with the intention of removing it later when there is an easy way to not do so is asking for trouble.