add --version flag to cli arguments

SIGNOFF

@@ -63,3 +63,4 @@ Paul Bransford (draeath) <draeath@gmail.com>
 Mark Langsdorf (mlangsdorf) <mark.langsdorf@gmail.com> / <mlangsdo@redhat.com>
 Ratul Saha (sahaRatul) <ratul.saha@arrakis.in> / <50.ratulsaha@gmail.com>
 Davis Bray (Kaltag1925) <pdavisbray@gmail.com>
+Nicolas Appriou <nicolas.appriou@gmail.com>

src/main.cpp

@@ -33,6 +33,7 @@
 #include "filesystem.h"
 #include "game.h"
 #include "game_ui.h"
+#include "get_version.h"
 #include "input.h"
 #include "loading_ui.h"
 #include "main_menu.h"
@@ -194,6 +195,34 @@ void printHelpMessage( const FirstPassArgs &first_pass_arguments,
     }
 }
 
+
+/**
+ * Displays current application version and compile options values
+ */
+void printVersionMessage()
+{
+#if defined(TILES)
+    const bool hasTiles = true;
+#else
+    const bool hasTiles = false;
+#endif
+
+#if defined(SDL_SOUND)
+    const bool hasSound = true;
+#else
+    const bool hasSound = false;
+#endif
+
+    printf( "Cataclysm Dark Days Ahead: %s\n\n"
+            "%ctiles, %csound\n\n"
+            "data dir: %s\nuser dir: %s\n",
+            getVersionString(),
+            hasTiles ? '+' : '-',
+            hasSound ? '+' : '-' ,
+            PATH_INFO::datadir().c_str(),
+            PATH_INFO::user_dir().c_str() );
+}
+
 template<typename ArgHandlerContainer>
 void process_args( const char **argv, int argc, const ArgHandlerContainer &arg_handlers )
 {
@@ -499,6 +528,11 @@ cli_opts parse_commandline( int argc, const char **argv )
         std::exit( 0 );
     }
 
+    if( std::count( argv, argv + argc, std::string( "--version" ) ) ) {
+        printVersionMessage();
+        std::exit( 0 );
+    }
+
     // skip program name
     --argc;
     ++argv;