#include <dirent.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>

#include <errno.h>

static int do_ls(const char *dir)
{
    int fd;
    struct dirent *dirent;
    int nbytes;
    char tmpbuf[256];
    stat_t sbuf;

    union {
        struct dirent dirent;
        char buf[4096];
    } lsb;

    fd = open(dir, O_RDONLY, 0600);
    if (fd < 0)
    {
        fprintf(stderr, "ls: unable to open \"%s\": errno %d\n", dir, errno);
        return 1;
    }

    while ((nbytes = getdents(fd, &lsb.dirent, sizeof(lsb))) > 0)
    {
        dirent = &lsb.dirent;

        if (nbytes % sizeof(struct dirent))
        {
            fprintf(stderr,
                    "ls: incorrect return value from getdents (%d):"
                    " not a multiple of sizeof(struct dirent) (%ld)\n",
                    nbytes, sizeof(struct dirent));
            return 1;
        }
        do
        {
            int reclen;
            int size;

            snprintf(tmpbuf, sizeof(tmpbuf), "%s/%s", dir, dirent->d_name);
            if (0 == stat(tmpbuf, &sbuf))
            {
                size = sbuf.st_size;
            }
            else
            {
                size = 0;
            }

            reclen = sizeof(struct dirent);
            fprintf(stdout, "%7d  %-20s   %d\n", size, dirent->d_name,
                    dirent->d_ino);
            dirent = (struct dirent *)(((char *)dirent) + reclen);
            nbytes -= reclen;
        } while (nbytes);
    }
    if (nbytes < 0)
    {
        if (errno == ENOTDIR)
        {
            fprintf(stdout, "%s\n", dir);
        }
        else
        {
            fprintf(stderr, "ls: couldn't list %s: errno %d\n", dir, errno);
        }
    }

    if (close(fd) < 0)
    {
        fprintf(stderr, "ls: close %s: errno %d\n", dir, errno);
    }
    return 0;
}

int main(int argc, char **argv)
{
    int ret;

    if (argc < 2)
    {
        ret = do_ls(".");
    }
    else if (argc < 3)
    {
        ret = do_ls(argv[1]);
    }
    else
    {
        int error;
        int argn;

        error = 0;
        for (argn = 1; argn < argc; argn++)
        {
            fprintf(stdout, "%s:\n", argv[argn]);
            error += do_ls(argv[argn]);
            fprintf(stdout, "\n");
        }
        ret = error;
    }
    return ret;
}