Hi erik, [erik]> I want my encryption and decryption program display how much memory are usage in encryption and decryption process. That varies depending on your platform. I recommend looking at the source code for ps (process status) or top, to glean how they calculate rss, rsz, tsiz, and vsz. ps and top source code: http://directory.fsf.org/project/procps/ If you don¹t need to monitor your program from within your program, you may want to use ps and/or top in a separate process to monitor your encryption/decryption process¹s footprint. That would be easier, I suspect. There are also Microsoft Windows equivalents written by Mark Russinovich, located at http://sysinternals.com (recently acquired by Microsoft). I don't think the source code is available, but you could you those tools in a separate process to monitor your encryption/decryption process's footprint. Alternatively, you could intercept malloc (and calloc, realloc, and perhaps valloc) and sum up all memory allocations on the heap, then call the real Standard C malloc. That would give you "all memory ever allocated" footprint. If you also wanted to keep track of high water memory allocation, you'd have to intercept free and figure out how the heap stores the memory block's size (or record the block size yourself in your intercepted the malloc). HTH, --Eljay
