Поковырять под gdb

gistfile1.txt

const int bufferSize = 32;

void first()
{
  char buffer[bufferSize];
  memset( buffer, 'A', sizeof( buffer ) );
}

void second()
{
  char buffer[bufferSize];
  memset( buffer, 'B', bufferSize / 2 );
  printf( "%s", buffer );
}

int main()
{
  first();
  second();
}