malloc, calloc and realloc

[mattias1975]

Hello!

What is the differenc betwen malloc, calloc ond realloc?
The only thing i know is that malloc is used for alocating memory.
I have a bug in my code. The first time i use malloc everything works. But the next time at the same row the program "hangs up" at the point where i am calling the malloc. Whats wrong?
I am freeing the memory with free(). Should i use calloc or realloc instead?

Thank you

 

[ArkM]

void *malloc( size_t size );
void *calloc( size_t num, size_t size );
void *realloc( void *memblock, size_t size );

All three functions in principle do the same work. Differences are:
1. calloc() allocates num*size bytes and initializes this memory chunk with zeroes (malloc() returns a pointer to undefined contents).
2. realloc() may deallocate memory if size == 0 and saves previous contents of reallocated memory chunk if memblock != 0 and size > 0). Be careful: realloc() may return different pointer (and an old value of memblock is now undefined in that case).

So, no valuable differences in this mechanics and you may mix these three function calls as you wish (don't forget free() returned pointers. You never should, you may if you wish...

 

[Salem]

I think you've got many more issues of buffer overrun to fix

http://www.tek-tips.com/viewthread.cfm?qid=935598

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