Getting OS version numbers for Linux.

base/sys_info_posix.cc

 // Copyright (c) 2011 The Chromium 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 "base/sys_info.h"
 
 #include <errno.h>
 #include <stddef.h>
 #include <stdint.h>
 #include <string.h>
@@ skipping 165 matching lines @@
 std::string SysInfo::OperatingSystemVersion() {
   struct utsname info;
   if (uname(&info) < 0) {
     NOTREACHED();
     return std::string();
   }
   return std::string(info.release);
 }
 #endif
 
+#if !defined(OS_MACOSX) && !defined(OS_ANDROID)
+// static
+void SysInfo::OperatingSystemVersionNumbers(int32_t* major_version,
+                                            int32_t* minor_version,
+                                            int32_t* bugfix_version) {
+  struct utsname info;
+  *major_version = 0;
+  *minor_version = 0;
+  *bugfix_version = 0;
+  if (uname(&info) < 0) {
+    NOTREACHED();
+    return;
+  }
+  sscanf(info.release, "%d.%d.%d", major_version, minor_version,

[dcheng, 2017/03/21 06:51:17]

Is the formatting of |release| guaranteed by some standard?

[dcheng, 2017/03/21 06:53:37]

Also, I'd probably prefer the approach that iOS uses:
https://cs.chromium.org/chromium/src/base/sys_info_ios.mm?rcl=60d92c2f3ff60c2...

[romax, 2017/03/21 18:17:33]

Tried a search online and didn't find a standard format for |release|.
Also moved the '=0's into the error case calling uname(&info), is it reasonable
to have default values here?

+         bugfix_version);
+}
+#endif
+
 // static
 std::string SysInfo::OperatingSystemArchitecture() {
   struct utsname info;
   if (uname(&info) < 0) {
     NOTREACHED();
     return std::string();
   }
   std::string arch(info.machine);
   if (arch == "i386" || arch == "i486" || arch == "i586" || arch == "i686") {
     arch = "x86";
   } else if (arch == "amd64") {
     arch = "x86_64";
   }
   return arch;
 }
 
 // static
 size_t SysInfo::VMAllocationGranularity() {
   return getpagesize();
 }
 
 }  // namespace base