Add Git-derived version reporting

typefactory/main.cpp

@@ -9,6 +9,10 @@
 #include "convertorg.h"
 #include "typefactory.h"
 
+#ifndef KINDLE2NOTES_VERSION
+#define KINDLE2NOTES_VERSION "unknown"
+#endif
+
 using ConverterFactory = TypeFactory<std::string, Converter, std::string>;
 
 static constexpr std::array<const char *, 4> kSupportedTypes = {
@@ -19,11 +23,13 @@ struct CliArgs {
   std::string input;
   std::string output;
   std::string type;
+  bool version = false;
 };
 
 static void print_usage (const char *argv0) {
   std::cerr << "Usage: " << argv0
-            << " --input <file> --output <file> --type <type>\n";
+            << " --input <file> --output <file> --type <type>\n"
+            << "       " << argv0 << " --version\n";
 }
 
 static void print_supported_types() {
@@ -47,12 +53,13 @@ static bool parse_args (int argc, char **argv, CliArgs &out) {
     {"input",  required_argument, nullptr, 'i'},
     {"output", required_argument, nullptr, 'o'},
     {"type",   required_argument, nullptr, 't'},
+    {"version", no_argument,      nullptr, 'v'},
     {"help",   no_argument,       nullptr, 'h'},
     {nullptr,  0,                 nullptr,  0 }
   };
 
   int c = 0;
-  while ((c = ::getopt_long (argc, argv, "i:o:t:h", long_opts, nullptr)) != -1) {
+  while ((c = ::getopt_long (argc, argv, "i:o:t:vh", long_opts, nullptr)) != -1) {
     switch (c) {
       case 'i':
         out.input = optarg;
@@ -63,6 +70,9 @@ static bool parse_args (int argc, char **argv, CliArgs &out) {
       case 't':
         out.type = optarg;
         break;
+      case 'v':
+        out.version = true;
+        break;
       case 'h':
         print_usage (argv[0]);
         return false;
@@ -72,7 +82,8 @@ static bool parse_args (int argc, char **argv, CliArgs &out) {
     }
   }
 
-  if (out.input.empty() || out.output.empty() || out.type.empty()) {
+  if (!out.version &&
+      (out.input.empty() || out.output.empty() || out.type.empty())) {
     print_usage (argv[0]);
     return false;
   }
@@ -85,6 +96,11 @@ int main (int argc, char **argv) {
   if (!parse_args (argc, argv, args))
     return 1;
 
+  if (args.version) {
+    std::cout << "kindle2notes " << KINDLE2NOTES_VERSION << '\n';
+    return 0;
+  }
+
   const ConverterFactory factory = build_converter_factory();
   if (!factory.contains (args.type)) {
     std::cerr << "Unsupported output type: " << args.type << '\n';