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 get added to the newlib

[Mark Seaborn, 2015/04/15 18:14:18]

"gets"

[Sam Clegg, 2015/04/15 20:46:39]

Done.

+ * headers.
+ */
+int utimes(const char *filename, const struct timeval tv[2]);
+
+/*
+ * Implementation of utime based on the utimes.  utime works just like utimes

[Mark Seaborn, 2015/04/15 18:14:18]

"the utimes" -> "utimes"

Suggestion: adding "()" to function names makes it clear you're referring to
functions (i.e. "utimes()")

[Sam Clegg, 2015/04/15 20:46:40]

Done.

+ * but only support timestamps with a granularity of one second (time_t). This

[Mark Seaborn, 2015/04/15 18:14:18]

"supports"

[Sam Clegg, 2015/04/15 20:46:40]

Done.

+ * means we we can use utimes to impelement utime by simply setting tv_sec

[Mark Seaborn, 2015/04/15 18:14:18]

"implement".  Also, you mean "tv_usec" not "tv_sec".

[Sam Clegg, 2015/04/15 20:46:40]

Done.

+ * 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);
+}