Toy example illustrating that on Linux memory is initialized when used.

memtest.c

#include <stdlib.h>
#include <string.h>
#include <unistd.h>

int main() {
    // Allocate 16GB of memory
    size_t size = 16UL * 1024 * 1024 * 1024;
    char* memory = malloc(size);

    // Access only some memory in the middle
    size_t middle = size / 2;
    memory[middle] = 42;

    // Sleep for a while to allow for memory usage inspection
    sleep(6);

    free(memory);
    return 0;
}

// To compile this program, use the following command:
// gcc -o memtest memtest.c

// To run this program and measure its memory usage, use the following command:
// /usr/bin/time -v ./memtest

// Please note that the actual memory usage might be different depending on the system's memory management.