Add utime implementation to libnacl

src/untrusted/nacl/utime.c

+/*
+ * Copyright 2015 The Native Client Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <errno.h>
+#include <sys/types.h>
+#include <sys/time.h>
+#include <utime.h>
+
+/*
+ * TODO(sbc): remove this once utimes declaration gets added to the newlib
+ * headers.
+ */
+int utimes(const char *filename, const struct timeval tv[2]);
+
+/*
+ * Implementation of utime() based on utimes().  utime() works just like
+ * utimes() but only supports timestamps with a granularity of one second
+ * (time_t). This means we we can use utimes() to implement utime() by simply
+ * setting tv_usec fields to zero.
+ */
+int utime(const char *filename, const struct utimbuf *buf) {
+  struct timeval times[2];
+  struct timeval *tv = NULL;
+  if (buf != NULL) {
+    times[0].tv_sec = buf->actime;
+    times[1].tv_sec = buf->modtime;
+    times[0].tv_usec = 0;
+    times[1].tv_usec = 0;
+    tv = times;
+  }
+
+  return utimes(filename, tv);
+}