Check heap size / set heap for system call

["Puetz, Oliver P11M22" <Puetz.Oliver@xxxxxxxxxxx>]

Hi,

I'm working on Linux with gcc 3.4.6.

Within program A I execute a binary B (sources available) via
system("blahblah"), but this binary B terminates with a malloc error.

So, 
 - is there a possibility to check the amount of free heap, so I can
report this value within B?
 - a possibility to set the heap size for the binary to be executed
within A?

Thanks in advance

Oliver