Working on the command line parameters.

src/main.cpp

@@ -5,6 +5,8 @@
 #include <boost/program_options/variables_map.hpp>
 #include <boost/program_options/options_description.hpp>
 #include <boost/program_options/parsers.hpp>
+#include <sstream>
+#include <cstring>
 
 #ifndef NDEBUG
 #define UNDEF_NDEBUG
@@ -19,14 +21,52 @@
 namespace {
 	///-------------------------------------------------------------------------
 	///-------------------------------------------------------------------------
-	void GetCommandLine (boost::program_options::variables_map& parVarMap, int parArgc, const char* const parArgv[]) {
-		boost::program_options::options_description desc("Program parameters");
-		desc.add_options()
-			("help", "show this help screen")
+	const char* GetBaseName (const char* parPath) {
+		const size_t len = std::strlen(parPath);
+		const char* found;
+		const char* currSearch = parPath;
+		do {
+			found = currSearch;
+			currSearch = std::find(found, parPath + len, '/');
+		} while (currSearch++ != parPath + len);
+
+		return found;
+	}
+
+	///-------------------------------------------------------------------------
+	///-------------------------------------------------------------------------
+	bool GetCommandLine (boost::program_options::variables_map& parVarMap, int parArgc, const char* const parArgv[]) {
+		const char* const programName = parArgv[0];
+		std::ostringstream oss;
+		oss << "Usage is " << GetBaseName(parArgv[0]) << " [options] <from language> <to language> <search term>; parameters";
+		boost::program_options::options_description desc(oss.str());
+		boost::program_options::positional_options_description positionals;
+		positionals.add("source-lang", 0);
+		positionals.add("dest-lang", 1);
+		positionals.add("word", 2);
+
+		boost::program_options::options_description hidden("hidden options");
+		hidden.add_options()
+			("source-lang", boost::program_options::value<std::string>(), "source language")
+			("dest-lang", boost::program_options::value<std::string>(), "dest language")
+			("word", boost::program_options::value<std::string>(), "search term")
 		;
 
-		boost::program_options::store(boost::program_options::parse_command_line(parArgc, parArgv, desc), parVarMap);
+		desc.add_options()
+			("help,h", "show this help screen")
+			("listlanguages,l", "list available languages with their codes")
+		;
+
+		boost::program_options::options_description commandLine;
+		commandLine.add(desc).add(hidden);
+		boost::program_options::store(boost::program_options::command_line_parser(parArgc, parArgv).options(commandLine).positional(positionals).run(), parVarMap);
 		boost::program_options::notify(parVarMap);
+		bool shownSomething = false;
+		if (parVarMap.count("help")) {
+			std::cout << desc << "\n";
+			shownSomething = true;
+		}
+		return shownSomething;
 	}
 } //unnamed namespace
 
@@ -36,7 +76,22 @@ int main (int parArgc, const char* const parArgv[]) {
 	WordReference wref("en", "it");
 
 	boost::program_options::variables_map vm;
-	GetCommandLine(vm, parArgc, parArgv);
-	std::cout << wref.GetHttpLink("north face") << "\n© WordReference.com" << std::endl;
+	if (GetCommandLine(vm, parArgc, parArgv))
+		return 0;
+
+	if (vm.count("listlanguages")) {
+		std::vector<const std::string*> codes, names;
+		GetAvailableLanguages(codes, names);
+		std::cout << "Supported languages are:\n";
+		for (size_t z = 0; z < codes.size(); ++z) {
+			std::cout << "\t" << *names[z] << " [" << *codes[z] << "]\n";
+		}
+		std::cout << "\n";
+		std::cout << "Note that the current WordReference specifications (Aug 2013) says:\n\"";
+		std::cout << "Only to and from English. We do not currently offer any combination that\ndoes not include English (such as Spanish-French).\"\n";
+		std::cout << "This program does not enforce this rule, but it may malfunction if you\nchoose the wrong languages.\n";
+		return 0;
+	}
+	std::cout << wref.GetHttpLink("north face") << "\nWritten by King_DuckZ; © WordReference.com" << std::endl;
 	return 0;
 }