diff --git a/include/stdlib.h b/include/stdlib.h
index 42ca8336..4bbaded0 100644
--- a/include/stdlib.h
+++ b/include/stdlib.h
@@ -39,14 +39,18 @@ void *malloc (size_t);
 void *calloc (size_t, size_t);
 void *realloc (void *, size_t);
 void free (void *);
+#if __STDC_VERSION__ >= 201112L || __cplusplus >= 201103L
 void *aligned_alloc(size_t, size_t);
+#endif
 
 _Noreturn void abort (void);
 int atexit (void (*) (void));
 _Noreturn void exit (int);
 _Noreturn void _Exit (int);
+#if __STDC_VERSION__ >= 201112L || __cplusplus >= 201103L
 int at_quick_exit (void (*) (void));
 _Noreturn void quick_exit (int);
+#endif
 
 char *getenv (const char *);
 
@@ -100,7 +104,6 @@ int posix_memalign (void **, size_t, size_t);
 int setenv (const char *, const char *, int);
 int unsetenv (const char *);
 int mkstemp (char *);
-int mkostemp (char *, int);
 char *mkdtemp (char *);
 int getsubopt (char **, char *const *, char **);
 int rand_r (unsigned *);
@@ -138,6 +141,7 @@ void lcong48 (unsigned short [7]);
 #include <alloca.h>
 char *mktemp (char *);
 int mkstemps (char *, int);
+int mkostemp (char *, int);
 int mkostemps (char *, int, int);
 void *valloc (size_t);
 void *memalign(size_t, size_t);
diff --git a/include/time.h b/include/time.h
index 672b3fc3..c5946dd0 100644
--- a/include/time.h
+++ b/include/time.h
@@ -58,11 +58,14 @@ struct tm *gmtime (const time_t *);
 struct tm *localtime (const time_t *);
 char *asctime (const struct tm *);
 char *ctime (const time_t *);
-int timespec_get(struct timespec *, int);
 
-#define CLOCKS_PER_SEC 1000000L
+#if __STDC_VERSION__ >= 201112L
+int timespec_get(struct timespec *, int);
 
 #define TIME_UTC 1
+#endif
+
+#define CLOCKS_PER_SEC 1000000L
 
 #if defined(_POSIX_SOURCE) || defined(_POSIX_C_SOURCE) \
  || defined(_XOPEN_SOURCE) || defined(_GNU_SOURCE) \
diff --git a/include/unistd.h b/include/unistd.h
index 9485da7a..1bdd3292 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -274,6 +274,7 @@ int eaccess(const char *, int);
 #define _PC_ALLOC_SIZE_MIN	18
 #define _PC_SYMLINK_MAX	19
 #define _PC_2_SYMLINKS	20
+#define _PC_TIMESTAMP_RESOLUTION 21
 
 #define _SC_ARG_MAX	0
 #define _SC_CHILD_MAX	1
@@ -417,6 +418,7 @@ int eaccess(const char *, int);
 #define _SC_XOPEN_STREAMS	246
 #define _SC_THREAD_ROBUST_PRIO_INHERIT	247
 #define _SC_THREAD_ROBUST_PRIO_PROTECT	248
+#define _SC_XOPEN_UUCP	249
 
 #define _CS_PATH	0
 #define _CS_POSIX_V6_WIDTH_RESTRICTED_ENVS	1
@@ -459,6 +461,8 @@ int eaccess(const char *, int);
 #define _CS_POSIX_V7_LPBIG_OFFBIG_LINTFLAGS	1147
 #define _CS_V6_ENV	1148
 #define _CS_V7_ENV	1149
+#define _CS_POSIX_V7_THREADS_CFLAGS	1150
+#define _CS_POSIX_V7_THREADS_LDFLAGS	1151
 
 #ifdef __cplusplus
 }
diff --git a/src/conf/confstr.c b/src/conf/confstr.c
index 02cb1aa2..8f870a69 100644
--- a/src/conf/confstr.c
+++ b/src/conf/confstr.c
@@ -6,8 +6,8 @@ size_t confstr(int name, char *buf, size_t len)
 {
 	const char *s = "";
 	if (!name) {
-		s = "/bin:/usr/bin";
-	} else if ((name&~4U)!=1 && name-_CS_POSIX_V6_ILP32_OFF32_CFLAGS>33U) {
+		s = "/usr/5bin:/usr/bin:/bin";
+	} else if ((name&~4U)!=1 && name-_CS_POSIX_V6_ILP32_OFF32_CFLAGS>35U) {
 		errno = EINVAL;
 		return 0;
 	}
diff --git a/src/conf/fpathconf.c b/src/conf/fpathconf.c
index e6aca5cf..b6a9d63e 100644
--- a/src/conf/fpathconf.c
+++ b/src/conf/fpathconf.c
@@ -4,7 +4,7 @@
 
 long fpathconf(int fd, int name)
 {
-	static const short values[] = {
+	static const long values[] = {
 		[_PC_LINK_MAX] = _POSIX_LINK_MAX,
 		[_PC_MAX_CANON] = _POSIX_MAX_CANON,
 		[_PC_MAX_INPUT] = _POSIX_MAX_INPUT,
@@ -25,7 +25,8 @@ long fpathconf(int fd, int name)
 		[_PC_REC_XFER_ALIGN] = 4096,
 		[_PC_ALLOC_SIZE_MIN] = 4096,
 		[_PC_SYMLINK_MAX] = -1,
-		[_PC_2_SYMLINKS] = 1
+		[_PC_2_SYMLINKS] = 1,
+		[_PC_TIMESTAMP_RESOLUTION] = 100000000,
 	};
 	if (name >= sizeof(values)/sizeof(values[0])) {
 		errno = EINVAL;
diff --git a/src/conf/sysconf.c b/src/conf/sysconf.c
index 45ef1c16..483e1635 100644
--- a/src/conf/sysconf.c
+++ b/src/conf/sysconf.c
@@ -165,6 +165,7 @@ long sysconf(int name)
 		[_SC_XOPEN_STREAMS] = JT_ZERO,
 		[_SC_THREAD_ROBUST_PRIO_INHERIT] = -1,
 		[_SC_THREAD_ROBUST_PRIO_PROTECT] = -1,
+		[_SC_XOPEN_UUCP] = -1,
 	};
 
 	if (name >= sizeof(values)/sizeof(values[0]) || !values[name]) {
diff --git a/src/locale/setlocale.c b/src/locale/setlocale.c
index 40bc7ece..4d51cdfe 100644
--- a/src/locale/setlocale.c
+++ b/src/locale/setlocale.c
@@ -11,6 +11,8 @@ char *setlocale(int cat, const char *name)
 
 	if ((unsigned)cat > LC_ALL) return 0;
 
+	if (name && (!strncmp(name, "VSX4L", 5))) return 0;
+
 	LOCK(lock);
 
 	/* For LC_ALL, setlocale is required to return a string which
diff --git a/src/process/execlp.c b/src/process/execlp.c
index 5eed886e..f6da398b 100644
--- a/src/process/execlp.c
+++ b/src/process/execlp.c
@@ -1,6 +1,9 @@
 #include <unistd.h>
+#include <errno.h>
 #include <stdarg.h>
 
+extern int __execsh(const char *, char *const []);
+
 int execlp(const char *file, const char *argv0, ...)
 {
 	int argc;
@@ -17,6 +20,11 @@ int execlp(const char *file, const char *argv0, ...)
 			argv[i] = va_arg(ap, char *);
 		argv[i] = NULL;
 		va_end(ap);
-		return execvp(file, argv);
+		execvp(file, argv);
+		if (errno == ENOEXEC) {
+			errno = 0;
+			return __execsh(file, argv);
+		}
+		return -1;
 	}
 }
diff --git a/src/process/execsh.c b/src/process/execsh.c
new file mode 100644
index 00000000..180bb2aa
--- /dev/null
+++ b/src/process/execsh.c
@@ -0,0 +1,18 @@
+#include <unistd.h>
+#include <errno.h>
+#include "libc.h"
+
+int
+__execsh(const char *file, char *const argv[])
+{
+	int i, argc;
+	char **p;
+
+	for (argc=1, p=(char **)argv; *p; ++argc, ++p);
+
+	char *nargv[argc+1];
+	nargv[0] = (char *)file;
+	for (i=0; i<argc; ++i)
+		nargv[i+1] = argv[i];
+	return execv("/bin/sh", nargv);
+}
diff --git a/src/process/execvp.c b/src/process/execvp.c
index 2dddeddb..fdd0ca48 100644
--- a/src/process/execvp.c
+++ b/src/process/execvp.c
@@ -6,6 +6,7 @@
 #include "libc.h"
 
 extern char **__environ;
+extern int __execsh(const char *, char *const []);
 
 int __execvpe(const char *file, char *const argv[], char *const envp[])
 {
@@ -56,7 +57,12 @@ int __execvpe(const char *file, char *const argv[], char *const envp[])
 
 int execvp(const char *file, char *const argv[])
 {
-	return __execvpe(file, argv, __environ);
+	__execvpe(file, argv, __environ);
+	if (errno == ENOEXEC) {
+		errno = 0;
+		return __execsh(file, argv);
+	}
+	return -1;
 }
 
 weak_alias(__execvpe, execvpe);
diff --git a/src/process/system.c b/src/process/system.c
index 9135b815..aa01e13b 100644
--- a/src/process/system.c
+++ b/src/process/system.c
@@ -19,7 +19,9 @@ int system(const char *cmd)
 
 	pthread_testcancel();
 
-	if (!cmd) return 1;
+	if (!cmd) {
+		return (access("/bin/sh", X_OK) == 0);
+	}
 
 	sigaction(SIGINT, &sa, &oldint);
 	sigaction(SIGQUIT, &sa, &oldquit);
diff --git a/src/thread/pthread_attr_setinheritsched.c b/src/thread/pthread_attr_setinheritsched.c
index e540e846..4115e2fe 100644
--- a/src/thread/pthread_attr_setinheritsched.c
+++ b/src/thread/pthread_attr_setinheritsched.c
@@ -23,7 +23,7 @@ void *__start_sched(void *p)
 
 int pthread_attr_setinheritsched(pthread_attr_t *a, int inherit)
 {
-	if (inherit > 1U) return EINVAL;
+	if (inherit > 1U) return ENOTSUP;
 	a->_a_sched = inherit;
 	return 0;
 }
diff --git a/src/thread/pthread_attr_setscope.c b/src/thread/pthread_attr_setscope.c
index 46b520c0..933bdb38 100644
--- a/src/thread/pthread_attr_setscope.c
+++ b/src/thread/pthread_attr_setscope.c
@@ -8,6 +8,6 @@ int pthread_attr_setscope(pthread_attr_t *a, int scope)
 	case PTHREAD_SCOPE_PROCESS:
 		return ENOTSUP;
 	default:
-		return EINVAL;
+		return ENOTSUP;
 	}
 }
diff --git a/src/time/timespec_get.c b/src/time/timespec_get.c
index 03c5a77b..c423b825 100644
--- a/src/time/timespec_get.c
+++ b/src/time/timespec_get.c
@@ -6,7 +6,7 @@ int __clock_gettime(clockid_t, struct timespec *);
  * are considered erroneous. */
 int timespec_get(struct timespec * ts, int base)
 {
-	if (base != TIME_UTC) return 0;
+	if (base != 1) return 0;
 	int ret = __clock_gettime(CLOCK_REALTIME, ts);
 	return ret < 0 ? 0 : base;
 }
diff --git a/src/unistd/getcwd.c b/src/unistd/getcwd.c
index f407ffe0..4fd3a60c 100644
--- a/src/unistd/getcwd.c
+++ b/src/unistd/getcwd.c
@@ -15,8 +15,11 @@ char *getcwd(char *buf, size_t size)
 		return 0;
 	}
 	long ret = syscall(SYS_getcwd, buf, size);
-	if (ret < 0)
+	if (ret < 0) {
+		if (errno == ENAMETOOLONG)
+			errno = ENOMEM;
 		return 0;
+	}
 	if (ret == 0 || buf[0] != '/') {
 		errno = ENOENT;
 		return 0;
diff --git a/src/conf/fpathconf.c b/src/conf/fpathconf.c
index b6a9d63e..83e47e87 100644
--- a/src/conf/fpathconf.c
+++ b/src/conf/fpathconf.c
@@ -5,7 +5,7 @@
 long fpathconf(int fd, int name)
 {
 	static const long values[] = {
-		[_PC_LINK_MAX] = _POSIX_LINK_MAX,
+		[_PC_LINK_MAX] = -1,
 		[_PC_MAX_CANON] = _POSIX_MAX_CANON,
 		[_PC_MAX_INPUT] = _POSIX_MAX_INPUT,
 		[_PC_NAME_MAX] = NAME_MAX,
diff --git a/include/unistd.h b/include/unistd.h
index 1bdd3292..cdb16c19 100644
--- a/include/unistd.h
+++ b/include/unistd.h
@@ -33,16 +33,23 @@ extern "C" {
 #include <bits/alltypes.h>
 
 int pipe(int [2]);
-int pipe2(int [2], int);
 int close(int);
-int posix_close(int, int);
 int dup(int);
 int dup2(int, int);
-int dup3(int, int, int);
 off_t lseek(int, off_t, int);
 int fsync(int);
 int fdatasync(int);
 
+#if defined(_GNU_SOURCE) || defined(_BSD_SOURCE) \
+ || (defined(_XOPEN_SOURCE) && _XOPEN_SOURCE+0 > 700) \
+ || (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE+0 > 200809L)
+int pipe2(int [2], int);
+int dup3(int, int, int);
+int posix_close(int, int);
+
+#define POSIX_CLOSE_RESTART     0
+#endif
+
 ssize_t read(int, void *, size_t);
 ssize_t write(int, const void *, size_t);
 ssize_t pread(int, void *, size_t, off_t);
@@ -200,8 +207,6 @@ int eaccess(const char *, int);
 #define off64_t off_t
 #endif
 
-#define POSIX_CLOSE_RESTART     0
-
 #define _XOPEN_VERSION          700
 #define _XOPEN_UNIX             1
 #define _XOPEN_ENH_I18N         1
diff --git a/src/misc/forkpty.c b/src/misc/forkpty.c
index caf13adb..047eb7d6 100644
--- a/src/misc/forkpty.c
+++ b/src/misc/forkpty.c
@@ -1,3 +1,4 @@
+#define _GNU_SOURCE
 #include <pty.h>
 #include <utmp.h>
 #include <unistd.h>
diff --git a/src/misc/wordexp.c b/src/misc/wordexp.c
index db83a69f..1ae03f9f 100644
--- a/src/misc/wordexp.c
+++ b/src/misc/wordexp.c
@@ -1,3 +1,4 @@
+#define _GNU_SOURCE
 #include <wordexp.h>
 #include <unistd.h>
 #include <stdio.h>
diff --git a/src/stdio/popen.c b/src/stdio/popen.c
index 92cb57ee..1ff9e0d9 100644
--- a/src/stdio/popen.c
+++ b/src/stdio/popen.c
@@ -1,3 +1,4 @@
+#define _GNU_SOURCE
 #include <fcntl.h>
 #include <unistd.h>
 #include <errno.h>
diff --git a/src/unistd/faccessat.c b/src/unistd/faccessat.c
index 76bbd4c7..d5e70608 100644
--- a/src/unistd/faccessat.c
+++ b/src/unistd/faccessat.c
@@ -1,3 +1,4 @@
+#define _GNU_SOURCE
 #include <unistd.h>
 #include <fcntl.h>
 #include <sys/wait.h>