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376 points turrini | 2 comments | | HN request time: 0.42s | source
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rkharsan64 ◴[] No.42146864[source]
On a general note, I would recommend any new (and experienced!) programmers to master the debugging tools of their ecosystem. I've seen countless experienced developers use printf-based debugging and waste hourse debugging something which could've been easily figured out by setting a breakpoint and stepping through your code. This is also a good way to understand code you're unfamiliar with.

This is one area where I believe a GUI tool is so much better: I can hover over variable names to view their values, expand and collapse parts of a nested structure, edit values easily, and follow execution in the same environment I write my code in.

Sure, it doesn't help much for some scenarios (one I've heard people mention is multithreaded code, where logs are better?), but for most people it's not that far from a superpower.

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VyseofArcadia ◴[] No.42147055[source]
But also, experienced programmers should never forget their printf debugging roots.

I was debugging something earlier this week that was hit like a hundred times in a tight loop. After the first dozen or so times I told gdb to continue, I realized, wait, this will be faster if I just fprintf some relevant information to a file. Sure enough the file pointed me in the right direction, and I was able to go back and get fancy with "disp" and "cond" and hit that breakpoint only when I needed to.

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1. mark_undoio ◴[] No.42147372[source]
You could also use GDB's Dynamic Printf (https://sourceware.org/gdb/current/onlinedocs/gdb.html/Dynam...) to do the logging directly from GDB.

Essentially you set it like a breakpoint (attaching a printf style string to a code location) and then just "continue" until you've gathered what you want.

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2. VyseofArcadia ◴[] No.42147801[source]
Oh sweet. I didn't know about that. I will be adding that to my toolbox.