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

int main(int argc, char **argv)
{
    char buf[] = {
        0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
        0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
        0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
        0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
        0, 1, 2, 3, 4, 5, 6, 7, 8, 9,
    };

    char *buf2 = malloc(sizeof(buf));
    memcpy(buf2, buf, sizeof(buf));

    for (size_t i = 0; i < sizeof(buf2); i++) {
        if (buf[i] != buf2[i]) {
            printf("buf[%zu] != buf2[%zu] !!\n", i, i);
            return -1;
        }
    }

    printf("copy ok.\n");
    free(buf2);
    return 0;
}