1 files changed, 91 insertions, 0 deletions
diff --git a/zen/sys_version.cpp b/zen/sys_version.cpp
new file mode 100644
index 00000000..46918315
--- /dev/null
+++ b/zen/sys_version.cpp
@@ -0,0 +1,91 @@
+// *****************************************************************************
+// * This file is part of the FreeFileSync project. It is distributed under    *
+// * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0          *
+// * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved *
+// *****************************************************************************
+
+#include "sys_version.h"
+    #include <iostream>
+    #include "file_io.h"
+    #include "shell_execute.h"
+
+using namespace zen;
+
+
+OsVersionDetail zen::getOsVersionDetail() //throw SysError
+{
+    /* prefer lsb_release:             lsb_release      Distributor ID: Debian
+         1. terser OS name                              Release:        8.11
+         2. detailed version number
+                                       /etc/os-release  NAME="Debian GNU/Linux"
+                                                        VERSION_ID="8"                         */
+    std::wstring osName;
+    std::wstring osVersion;
+    try
+    {
+        if (const auto [exitCode, output] = consoleExecute("lsb_release --id -s", std::nullopt); //throw SysError
+            exitCode != 0)
+            throw SysError(formatSystemError("lsb_release --id", replaceCpy(_("Exit code %x"), L"%x", numberTo<std::wstring>(exitCode)), output));
+        else
+            osName = trimCpy(output);
+
+        if (const auto [exitCode, output] = consoleExecute("lsb_release --release -s", std::nullopt); //throw SysError
+            exitCode != 0)
+            throw SysError(formatSystemError("lsb_release --release", replaceCpy(_("Exit code %x"), L"%x", numberTo<std::wstring>(exitCode)), output));
+        else
+            osVersion = trimCpy(output);
+    }
+    //lsb_release not available on some systems: https://freefilesync.org/forum/viewtopic.php?t=7191
+    catch (SysError&) // => fall back to /etc/os-release: https://www.freedesktop.org/software/systemd/man/os-release.html
+    {
+        std::string releaseInfo;
+        try
+        {
+            releaseInfo = getFileContent("/etc/os-release", nullptr /*notifyUnbufferedIO*/); //throw FileError
+        }
+        catch (const FileError& e) { throw SysError(replaceCpy(e.toString(), L"\n\n", L'\n')); } //errors should be further enriched by context info => SysError
+
+        for (const std::string& line : split(releaseInfo, '\n', SplitOnEmpty::skip))
+            if (startsWith(line, "NAME="))
+                osName = utfTo<std::wstring>(afterFirst(line, '=', IfNotFoundReturn::none));
+            else if (startsWith(line, "VERSION_ID="))
+                osVersion = utfTo<std::wstring>(afterFirst(line, '=', IfNotFoundReturn::none));
+        //PRETTY_NAME? too wordy! e.g. "Fedora 17 (Beefy Miracle)"
+
+        trim(osName,    true, true, [](char c) { return c == L'"' || c == L'\''; });
+        trim(osVersion, true, true, [](char c) { return c == L'"' || c == L'\''; });
+    }
+
+    if (osName.empty())
+        throw SysError(L"Operating system release could not be determined."); //should never happen!
+    //osVersion is usually available, except for Arch Linux: https://freefilesync.org/forum/viewtopic.php?t=7276
+    //  lsb_release Release is "rolling"
+    //  etc/os-release: VERSION_ID is missing
+
+    std::vector<std::wstring> verDigits = split<std::wstring>(osVersion, L'.', SplitOnEmpty::allow); //e.g. "7.7.1908"
+    verDigits.resize(2);
+
+    return OsVersionDetail
+    {
+        {
+            stringTo<int>(verDigits[0]),
+            stringTo<int>(verDigits[1])
+        },
+        osVersion, osName
+    };
+}
+
+
+OsVersion zen::getOsVersion()
+{
+    try
+    {
+        static const OsVersionDetail verDetail = getOsVersionDetail(); //throw SysError
+        return verDetail.version;
+    }
+    catch (const SysError& e)
+    {
+        std::cerr << utfTo<std::string>(e.toString()) << '\n';
+        return {}; //sigh, it's a jungle out there: https://freefilesync.org/forum/viewtopic.php?t=7276
+    }
+}