More sysconf(3)-y and pathconf(3)-y goodness from Brad.

ok guenther, millert (and me); bulk build test by naddy

src/include/unistd.h

@@ -1,4 +1,4 @@
-/*	$OpenBSD: unistd.h,v 1.70 2012/04/12 12:33:03 deraadt Exp $ */
+/*	$OpenBSD: unistd.h,v 1.71 2012/05/14 23:21:35 matthew Exp $ */
 /*	$NetBSD: unistd.h,v 1.26.4.1 1996/05/28 02:31:51 mrg Exp $	*/
 
 /*-
@@ -50,10 +50,102 @@
 #define F_TEST          3	/* test a section for locks by other procs */
 #endif
 
-#if __POSIX_VISIBLE
-#define _POSIX_REENTRANT_FUNCTIONS	1
-#define _POSIX_THREAD_SAFE_FUNCTIONS	200112L
-#endif
+/*
+ * POSIX options and option groups we unconditionally do or don't
+ * implement.  Please keep this list in alphabetical order.
+ *
+ * Anything which is defined as zero below **must** have an
+ * implementation for the corresponding sysconf() which is able to
+ * determine conclusively whether or not the feature is supported.
+ * Anything which is defined as other than -1 below **must** have
+ * complete headers, types, and function declarations as specified by
+ * the POSIX standard; however, if the relevant sysconf() function
+ * returns -1, the functions may be stubbed out.
+ */
+#define _POSIX_ADVISORY_INFO			(-1)
+#define _POSIX_ASYNCHRONOUS_IO			(-1)
+#define _POSIX_BARRIERS				200112L
+#define _POSIX_CHOWN_RESTRICTED			1
+#define _POSIX_CLOCK_SELECTION			(-1)
+#define _POSIX_CPUTIME				(-1)
+#define _POSIX_FSYNC				200112L
+#define _POSIX_IPV6				0
+#define _POSIX_JOB_CONTROL			1
+#define _POSIX_MAPPED_FILES			200112L
+#define _POSIX_MEMLOCK				200112L
+#define _POSIX_MEMLOCK_RANGE			200112L
+#define _POSIX_MEMORY_PROTECTION		200112L
+#define _POSIX_MESSAGE_PASSING			(-1)
+#define _POSIX_MONOTONIC_CLOCK			200112L
+#define _POSIX_NO_TRUNC				1
+#define _POSIX_PRIORITIZED_IO			(-1)
+#define _POSIX_PRIORITY_SCHEDULING		(-1)
+#define _POSIX_RAW_SOCKETS			200112L
+#define _POSIX_READER_WRITER_LOCKS		200112L
+#define _POSIX_REALTIME_SIGNALS			(-1)
+#define _POSIX_REGEXP				1
+#define _POSIX_SAVED_IDS			1
+#define _POSIX_SEMAPHORES			200112L
+#define _POSIX_SHARED_MEMORY_OBJECTS		(-1)
+#define _POSIX_SHELL				1
+#define _POSIX_SPAWN				200112L
+#define _POSIX_SPIN_LOCKS			200112L
+#define _POSIX_SPORADIC_SERVER			(-1)
+#define _POSIX_SYNCHRONIZED_IO			(-1)
+#define _POSIX_THREAD_ATTR_STACKADDR		200112L
+#define _POSIX_THREAD_ATTR_STACKSIZE		200112L
+#define _POSIX_THREAD_CPUTIME			(-1)
+#define _POSIX_THREAD_PRIO_INHERIT		(-1)
+#define _POSIX_THREAD_PRIO_PROTECT		(-1)
+#define _POSIX_THREAD_PRIORITY_SCHEDULING	(-1)
+#define _POSIX_THREAD_PROCESS_SHARED		(-1)
+#define _POSIX_THREAD_ROBUST_PRIO_INHERIT	(-1)
+#define _POSIX_THREAD_ROBUST_PRIO_PROTECT	(-1)
+#define _POSIX_THREAD_SAFE_FUNCTIONS		200112L
+#define _POSIX_THREAD_SPORADIC_SERVER		(-1)
+#define _POSIX_THREADS				200112L
+#define _POSIX_TIMEOUTS				200112L
+#define _POSIX_TIMERS				(-1)
+#define _POSIX_TRACE				(-1)
+#define _POSIX_TRACE_EVENT_FILTER		(-1)
+#define _POSIX_TRACE_INHERIT			(-1)
+#define _POSIX_TRACE_LOG			(-1)
+#define _POSIX_TYPED_MEMORY_OBJECTS		(-1)
+#define _POSIX2_C_BIND				200112L
+#define _POSIX2_C_DEV				(-1) /* need C99 utility */
+#define _POSIX2_CHAR_TERM			1
+#define _POSIX2_FORT_DEV			(-1) /* need fort77 utility */
+#define _POSIX2_FORT_RUN			200112L
+#define _POSIX2_LOCALEDEF			(-1)
+#define _POSIX2_PBS				(-1)
+#define _POSIX2_PBS_ACCOUNTING			(-1)
+#define _POSIX2_PBS_CHECKPOINT			(-1)
+#define _POSIX2_PBS_LOCATE			(-1)
+#define _POSIX2_PBS_MESSAGE			(-1)
+#define _POSIX2_PBS_TRACK			(-1)
+#define _POSIX2_SW_DEV				200112L
+#define _POSIX2_UPE				200112L
+#define _POSIX_V6_ILP32_OFF32			(-1)
+#define _POSIX_V6_ILP32_OFFBIG			0
+#define _POSIX_V6_LP64_OFF64			0
+#define _POSIX_V6_LPBIG_OFFBIG			0
+#define _POSIX_V7_ILP32_OFF32			(-1)
+#define _POSIX_V7_ILP32_OFFBIG			0
+#define _POSIX_V7_LP64_OFF64			0
+#define _POSIX_V7_LPBIG_OFFBIG			0
+
+#define _XOPEN_CRYPT				1
+#define _XOPEN_ENH_I18N				(-1) /* mandatory in XSI */
+#define _XOPEN_LEGACY				(-1)
+#define _XOPEN_REALTIME				(-1)
+#define _XOPEN_REALTIME_THREADS			(-1)
+#define _XOPEN_SHM				1
+#define _XOPEN_STREAMS				(-1)
+#define _XOPEN_UUCP				(-1)
+#define _XOPEN_UNIX				(-1)
+
+/* Define the POSIX.2 version we target for compliance. */
+#define _POSIX2_VERSION				199212L
 
 #ifndef NULL
 #ifdef 	__GNUG__