Dynamic allocation (I thought it would crash)
I've been trying to learn a bit about dynamic allocation in my noobish way, and I decided to see what would happen if I deliberately tried to cram too much data into a memory block that is too small to contain it all. Ironically the program seems to function correctly, printing out the full array, even though I've tried to make it overload. I can't figure out why.
Code:
/* Dynamic memory allocation */
#include <stdio.h>
#include <stdlib.h>
int main()
{
char size[5]; // Array deliberately set too small
int *memory_block;
int i;
char word[] = "abcdefghijklmnopqrs";
char c;
/* Allocate memory defined by char array 'size' */
memory_block = malloc(sizeof(size));
/* Check for allocation failure */
if(memory_block == NULL)
{
printf("Allocation Failed.\n");
exit(EXIT_FAILURE);
}else
printf("Memory Allocated.\n");
/* Copy data stored in 'word' into 'memory_block' */
for(i = 0; word[i]; i++)
{
memory_block[i] = word[i];
printf("%c\n", memory_block[i]);
}
/* Return memory to heap */
free(memory_block);
/* Exit */
printf("Press 'q' to exit:");
if((c = _getch()) == 'q')
return 0;
}
Output:
Memory Allocated
a
b
c
d
e
f
............
s
Press 'q' to exit:
