Add --version option that shows the CryFS version and exits.

ChangeLog.txt

@@ -2,6 +2,7 @@ Version 0.9.9 (unreleased)
 --------------
 Improvements:
 * Add --allow-filesystem-upgrade option which will upgrade old file systems without asking the user. This will be especially helpful for GUI tools.
+* Add --version option that shows the CryFS version and exits.
 
 Version 0.9.8
 --------------

doc/man/cryfs.1

@@ -19,7 +19,7 @@ cryfs \- cryptographic filesystem for the cloud
 [\fB\-\-\fR \fIfuse-options\fR]
 .br
 .\" show-ciphers syntax
-.B cryfs \-\-help\fR|\fB\-\-show-ciphers
+.B cryfs \-\-help\fR|\fB\-\-version\fR|\fB\-\-show-ciphers
 .
 .
 .
@@ -119,6 +119,12 @@ Show a help message containing short descriptions for all options.
 Show a list of all supported encryption ciphers.
 .
 .
+.TP
+\fB\-\-version\fR
+.
+Show the CryFS version number.
+.
+.
 .SS Encryption parameters
 .
 .TP

src/cryfs-cli/program_options/Parser.cpp

@@ -12,6 +12,7 @@ using cryfs::CryConfigConsole;
 using std::pair;
 using std::vector;
 using std::cerr;
+using std::cout;
 using std::endl;
 using std::string;
 using boost::optional;
@@ -105,6 +106,9 @@ po::variables_map Parser::_parseOptions(const vector<string> &options, const vec
     if (vm.count("show-ciphers")) {
         _showCiphersAndExit(supportedCiphers);
     }
+    if (vm.count("version")) {
+        _showVersionAndExit();
+    }
     po::notify(vm);
 
     return vm;
@@ -135,6 +139,7 @@ void Parser::_addAllowedOptions(po::options_description *desc) {
             ("show-ciphers", "Show list of supported ciphers.")
             ("unmount-idle", po::value<double>(), "Automatically unmount after specified number of idle minutes.")
             ("logfile", po::value<string>(), "Specify the file to write log messages to. If this is not specified, log messages will go to stdout, or syslog if CryFS is running in the background.")
+            ("version", "Show CryFS version number")
             ;
     desc->add(options);
 }
@@ -174,3 +179,8 @@ void Parser::_addPositionalOptionForBaseDir(po::options_description *desc, po::p
          << endl;
     exit(1);
 }
+
+[[noreturn]] void Parser::_showVersionAndExit() {
+  // no need to show version because it was already shown in the CryFS header before parsing program options
+  exit(1);
+}

src/cryfs-cli/program_options/Parser.h

@@ -21,6 +21,7 @@ namespace cryfs {
                                                        boost::program_options::positional_options_description *positional);
             [[noreturn]] static void _showHelpAndExit();
             [[noreturn]] static void _showCiphersAndExit(const std::vector<std::string> &supportedCiphers);
+            [[noreturn]] static void _showVersionAndExit();
             static boost::program_options::variables_map _parseOptionsOrShowHelp(const std::vector<std::string> &options, const std::vector<std::string> &supportedCiphers);
             static boost::program_options::variables_map _parseOptions(const std::vector<std::string> &options, const std::vector<std::string> &supportedCiphers);
             static void _checkValidCipher(const std::string &cipher, const std::vector<std::string> &supportedCiphers);

test/cryfs-cli/program_options/ParserTest.cpp

@@ -2,6 +2,7 @@
 #include <cryfs-cli/program_options/Parser.h>
 #include <cryfs/config/CryCipher.h>
 #include <cpp-utils/pointer/unique_ref_boost_optional_gtest_workaround.h>
+#include <gitversion/gitversion.h>
 
 using namespace cryfs;
 using namespace cryfs::program_options;
@@ -54,6 +55,16 @@ TEST_F(ProgramOptionsParserTest, ShowCiphers) {
     );
 }
 
+
+TEST_F(ProgramOptionsParserTest, Version) {
+    string expected = "CryFS Version " + gitversion::VersionString();
+    EXPECT_EXIT(
+        parse({"./myExecutable", "--version"}),
+        ::testing::ExitedWithCode(0),
+        expected.c_str()
+    );
+}
+
 TEST_F(ProgramOptionsParserTest, BaseDir_Absolute) {
     ProgramOptions options = parse({"./myExecutable", "/home/user/baseDir", "/home/user/mountDir"});
     EXPECT_EQ("/home/user/baseDir", options.baseDir());