#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <stdlib.h>
#include <unistd.h>
#include <fcntl.h>
#include <stdio.h>

static int do_mincore(char *path)
{
        unsigned long nr_pages, nr_present, i;
        struct stat statbuf;
        unsigned char *bits;
        int ret = 1;
        void *map;
        int fd;

        fd = open(path, O_RDONLY);
        if (fd == -1)
                goto out;

        if (fstat(fd, &statbuf) == -1)
                goto out_fd;

        nr_pages = (statbuf.st_size + 4095) / 4096;

        bits = malloc(nr_pages);
        if (bits == NULL)
                goto out_fd;

        map = mmap(NULL, statbuf.st_size, PROT_NONE, MAP_SHARED, fd, 0);
        if (map == MAP_FAILED)
                goto out_bits;

        if (mincore(map, statbuf.st_size, bits) == -1)
                goto out_map;

        nr_present = 0;
        for (i = 0; i < nr_pages; i++)
                if (bits[i])
                        nr_present++;
        printf("%lu/%lu %s\n", nr_present, nr_pages, path);
        ret = 0;
out_map:
        munmap(map, statbuf.st_size);
out_bits:
        free(bits);
out_fd:
        close(fd);
out:
        return ret;
}

int main(int ac, char **av)
{
        int ret = 0;
        int i;

        if (ac == 1) {
                printf("usage: mincore FILE...\n");
                return 1;
        }

        for (i = 1; i < ac; i++)
                ret |= do_mincore(av[i]);

        return ret;
}