Question

Help! My program seems to have memory leaks! http://ideone.com/qgDc0

How do I resolve this problem, and prevent it in the future (in C) ?

Answer 1

dont use C :D

Answer 2

But I need to use C, since that's the language I'm learning atm :(

Answer 3

engs = strconcat(translate_thousand(integer % 1000),
padstring(strconcat(pows_to_engs[placescount], padstring(engs))));

strconcat mallocs, but you only free engs. The intermediary call to strconcat is never tracked, and therefore never freed.

In general, valgrind: http://valgrind.org/ is often used for tracking down memory leaks. There are some decent UIs for it out there. Mac OS X also comes with Instruments, which has memory management helpers, though I'm not sure if they're aimed more to malloc/free or something else.

Generally speaking, you want to architect your program so that the malloc and free for any given thing happens in the same function, otherwise you're begging for memory leaks. Your strconcat should take in a pre-malloced pointer to work with, such that you have both the malloc(s) and free(s) in the calling function. This way it's easy to check and make sure that you have balanced mallocs and frees.

Answer 4

I've improved it a little bit, but I've also discovered another problem: when you input 0 it's calling free() more than it should.
http://ideone.com/3P3os

Answer 5

Wish I could learn how to properly manage memory in C.... I'm just a novice and already my code is exploding in several, colorful ways.

Answer 6

Alright. I've nearly eliminated all memory leaks and bad free() calls: http://ideone.com/5pBaJ

Anyone spot that last memory leak?

Answer 7

http://ideone.com/9LMM5

No more memory leaks! :-D

Answer 8

http://ideone.com/NHiTY