int alphasort(const struct dirent **, const struct dirent **);
int scandir(const char *, struct dirent ***, int (*)(const struct dirent *), int (*)(const struct dirent **, const struct dirent **));
-#ifdef _GNU_SOURCE
+#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE)
#define DT_UNKNOWN 0
#define DT_FIFO 1
#define DT_CHR 2