main for ku5-5

#include <stddef.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <sys/mman.h>
#include <fcntl.h>
#include <unistd.h>
#include <errno.h>


typedef uint32_t (*sumfunc_t)(void);
sumfunc_t generate(void *buf, size_t bufsize, uint32_t *array, size_t size) ;

uint32_t array[] = {1, 2, 3, 4, 5};
size_t size = 5;

int main() {
    int fd = open("tmp.txt", O_RDWR | O_CREAT | O_TRUNC);
    int ufd = fd;
    for (int i = 0; i < 4096; i++) {
        write(fd, array, 1);
    }
    fd = ufd;
    unsigned char * buf = mmap (NULL, 4096, PROT_WRITE|PROT_EXEC, MAP_SHARED|MAP_ANONYMOUS, fd, 0);
    if (buf == MAP_FAILED) {
        printf ("%i\n", errno);
        printf ("error\n");
        return 0;
    }
    uint32_t (*f1)(void) = generate(buf, 4096, array, size);
    printf("%u\n", f1());
    munmap(buf, 4096);
    close(fd);
 }