#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
/*
This program demonstrates how to:
1. Allocate a block of memory dynamically
2. Fill it with known values
3. Display a full bit‑level memory map of the allocated bytes
4. Intentionally create a memory leak by losing the pointer
IMPORTANT:
A memory leak cannot be inspected *after* it leaks,
because the pointer is lost. So we inspect the memory
BEFORE leaking it.
*/
// Print a bit-level memory map of a memory block
void printMemoryMap(const uint8_t* data, size_t size) {
printf("Bit-level memory map (%zu bytes):\n", size);
for (size_t i = 0; i < size; ++i) {
// Convert each byte to an 8-bit binary string
printf("Byte %02zu: ", i);
for (int bit = 7; bit >= 0; --bit) {
printf("%u", (data[i] >> bit) & 1);
}
printf(" (0x%02x)\n", data[i]);
}
}
int main() {
// Allocate memory (this block will be intentionally leaked)
size_t size = 8;
uint8_t* leakedBlock = (uint8_t*)malloc(size);
if (!leakedBlock) {
printf("Memory allocation failed.\n");
return 1;
}
// Fill memory with a recognizable pattern
for (size_t i = 0; i < size; ++i) {
leakedBlock[i] = (uint8_t)(i * 17); // arbitrary pattern
}
printf("Allocated memory at address: %p\n\n", (void*)leakedBlock);
// Show the bit-level memory map BEFORE leaking the memory
printMemoryMap(leakedBlock, size);
// INTENTIONAL MEMORY LEAK:
// We lose the only pointer to the allocated block.
// This situation is primarily called a memory leak,
// specifically known as a lost pointer or orphaned memory.
// It occurs when dynamically allocated memory (on the heap)
// cannot be accessed or freed because the program has lost
// the address stored in the pointer variable.
leakedBlock = NULL;
printf("\nMemory leak created: pointer lost, "
"block still allocated but unreachable.\n");
return 0;
}
/*
run:
Allocated memory at address: 0x17b352a0
Bit-level memory map (8 bytes):
Byte 00: 00000000 (0x00)
Byte 01: 00010001 (0x11)
Byte 02: 00100010 (0x22)
Byte 03: 00110011 (0x33)
Byte 04: 01000100 (0x44)
Byte 05: 01010101 (0x55)
Byte 06: 01100110 (0x66)
Byte 07: 01110111 (0x77)
Memory leak created: pointer lost, block still allocated but unreachable.
*/
