#define _FILE_OFFSET_BITS 64
-#include <features.h>
-
-//#define _POSIX_C_SOURCE 200809L
-//#define _XOPEN_SOURCE 600
-//#define _BSD_SOURCE
-//#define _SVID_SOURCE
+// This isn't in the spec, but it's how we determine what we're using.
-//#include <stdio.h>
-//#define fdprintf(...) dprintf(__VA_ARGS__)
+#include <features.h>
#ifdef __GLIBC__
// An SUSv4 function that glibc refuses to #define without crazy #defines,
// see http://pubs.opengroup.org/onlinepubs/9699919799/functions/strptime.html
#include <time.h>
char *strptime(const char *buf, const char *format, struct tm *tm);
+// Another one. "Function prototypes shall be provided." but aren't.
+// http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/unistd.h.html
+char *crypt(const char *key, const char *salt);
#endif
#ifdef __GNUC__