In this post weвЂ™ll look briefly at how the four segments of memory are represented. The nice thing about C is that it allows you to peer into the machine using printf and the %p specifier to output hexadecimal addresses of variables and the like.

Memory in C вЂ“ peeking at the HEX addressesВ (i) Now letвЂ™s look at the memory a little closer. If the hexadecimal addresses are output: HEAPДynamic string: dynamic char array at 0x7f92a0c03340 Pch = (char *) malloc(strlen('a dynamic string') + 1) Here we create some dynamic structures: int *pnt unused chunks of memory can be interspersed amongst active blocks of memory. Because this memory can be created and freed by the program in various positions in the code, heap memory can become fragmented, i.e. Dynamic memory comes into existence when malloc() (or similar) is called, and itвЂ™s freed when free() is called. The heap is of course where all the dynamic things are stored. For example, array is at position 140734795270624, which signifies the position of element array. the memory addresses lower as variables are created. Variable: size=4 memory position=140734795270676ДЄrray: size=40 memory position=140734795270624ДЄutoString: size=16 memory position=140734795270608ДЇrom this it is possible to discern that the variables are creating in descending order (i.e. Now letвЂ™s look at the memory a little closer (with HEX converted to decimal).

If the hexadecimal addresses are output: STACKДЄuto string: character array at 0x7fff5f7ac9d0 Here are some examples: int variable = 20 The stack is used to store things like local variables, function frames, and static arrays.

Stack smashing detected on arrray