How can I know how much memory my process uses?

What platform r u on

I run on Solaris 5.8 or linux

I think you should keep track of your dynamic memory allocation functions - malloc, calloc, free, realloc etc

Also,
Have a look at this site

 http://www.dmalloc.com

A similar question was previously asked

here's a good discussion for the same

http://www-level3.experts-exchange.com/questions/20727263/knowing-the-memory-consumption-of-my-process.html

My code is a legacy one with thousands of lines. I can't keep track of each allocation.
I'm seeking a function that can tell me the amounr of memory allocated and or the free memory.
Is there such a function?

As I said, the link on EE would be helpful
I am listing one of the solutions from there

Say u are using malloc for dynamic allocation

then just do this

#define malloc malloc_wrapper

malloc_wrapper ( same_arguments_as_malloc )
{
     /* do the accounting */
     malloc ( ... );
     return ...;
}