hi
does anyone know how i can decrease the size of allocated memory? for example if i have an array and i want to cut it after 400 entries and there should no memory be wasted

: hi
: does anyone know how i can decrease the size of allocated memory? for example if i have an array and i want to cut it after 400 entries and there should no memory be wasted
:

allocate the array dynamically, use malloc() for initial allocation, then use realloc() when you want to reduce or expand it. you can't change the size of a statically allocated array.

: : hi
: : does anyone know how i can decrease the size of allocated memory? for example if i have an array and i want to cut it after 400 entries and there should no memory be wasted
: :
:
: allocate the array dynamically, use malloc() for initial allocation, then use realloc() when you want to reduce or expand it. you can't change the size of a statically allocated array.
:
i thought i can use realloc only with sizes larger than the actual size. is this wrong?
would be nice...

This message was edited by stober at 2005-4-8 7:21:26

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: :
: i thought i can use realloc only with sizes larger than the actual size. is this wrong?
: would be nice...
:

Yes, that is wrong.
http://www.opengroup.org/onlinepubs/007908799/xsh/realloc.html

realloc() can be used to shrink the allocation too, but that doesn't mean the program will gain more memory. It only means that the difference is now available to allocation by something else. malloc() and realloc() only work with contiguous memory locations, and most operating systems do not attempt to defragment memory unless there are two more adjacent free memory blocks.

So reducing the size of allocated arrays may, or may not, give your program more memory. There's a lot of ifs, ands and buts.

thx for your help man :)
very appreciated...