Parse options through boost program_options.

CMakeLists.txt

@@ -1,19 +1,15 @@
-cmake_minimum_required(VERSION 2.8 FATAL_ERROR)
+cmake_minimum_required(VERSION 3.0 FATAL_ERROR)
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}/cmake/Modules/")
-project(duckscraper CXX)
+project(duckscraper VERSION 0.2 LANGUAGES CXX)
-
-add_subdirectory(lib/tidy)
-add_subdirectory(lib/curlcpp)
 
 include(GetGitRevisionDescription)
 find_package(PugiXML REQUIRED)
+find_package(Boost 1.32.0 COMPONENTS program_options)
 
 set(CMAKE_CXX_FLAGS_DEBUG "${CMAKE_CXX_FLAGS_DEBUG} -std=c++11 -Wall -Wextra -g -O0 -fno-omit-frame-pointer")
 set(CMAKE_CXX_FLAGS_RELEASE "${CMAKE_CXX_FLAGS_RELEASE} -std=c++11 -Wall -Wextra -g -O3 -fomit-frame-pointer")
 
 set(DEFAULT_USER_AGENT "DuckScraper")
-set(PROJECT_VERSION_MAJOR "0")
-set(PROJECT_VERSION_MINOR "1")
 set(PROJECT_VERSION_BETA "1")
 get_git_head_revision(GIT_REFSPEC PROJECT_VERSION_GIT)
 
@@ -25,7 +21,8 @@ configure_file(
 include_directories(SYSTEM
 	lib/tidy/include
 	${PUGIXML_INCLUDE_DIR}
-	${CURLCPP_SOURCE_DIR}/include
+	lib/curlcpp/include
+	${Boost_INCLUDE_DIRS}
 )
 include_directories(
 	src/
@@ -41,4 +38,15 @@ target_link_libraries(${PROJECT_NAME}
 	tidy-share
 	${PUGIXML_LIBRARIES}
 	curlcpp
+	${Boost_LIBRARIES}
 )
+
+#unset those variables so cmake files from dependencies won't complain about
+#new/old policy. Those unset statements can be removed once both libraries bump
+#their cmake_minimum_required to 3.0+.
+unset(PROJECT_VERSION_MAJOR)
+unset(PROJECT_VERSION_MINOR)
+unset(PROJECT_VERSION)
+set(BUILD_SHARED_LIB ON) #for tidy
+add_subdirectory(lib/tidy)
+add_subdirectory(lib/curlcpp)

src/main.cpp

@@ -6,32 +6,84 @@
 #include <sstream>
 #include <utility>
 #include <ciso646>
+#include <boost/program_options.hpp>
+#include <unistd.h>
+
+#define STRINGIZE_IMPL(s) #s
+#define STRINGIZE(s) STRINGIZE_IMPL(s)
+
+namespace po = boost::program_options;
 
 namespace {
 	typedef std::pair<int, int> LineColType;
 
 	LineColType line_col_from_offset ( ptrdiff_t parOffset, const std::string& parData );
+
+	const char* const g_version_string =
+		PROGRAM_NAME " v" STRINGIZE(VERSION_MAJOR) "." STRINGIZE(VERSION_MINOR)
+#if VERSION_BETA
+			"b"
+#endif
+		;
+
+	bool parse_commandline (int parArgc, char* parArgv[], po::variables_map parVarMap) {
+		po::options_description desc("General");
+		desc.add_options()
+			("help,h", "Produces this help message")
+			("version", "Prints the program's version and quits")
+		;
+		po::options_description positional_options("Positional options");
+		positional_options.add_options()
+			("input-url", po::value<std::string>(), "Input URL")
+			("xpath", po::value<std::string>(), "XPath expression")
+		;
+		po::options_description all("Available options");
+		all.add(desc).add(positional_options);
+		po::positional_options_description pd;
+		pd.add("input-url", 1).add("xpath", 1);
+		po::store(po::command_line_parser(parArgc, parArgv).options(all).positional(pd).run(), parVarMap);
+		po::notify(parVarMap);
+
+		if (parVarMap.count("help")) {
+			po::options_description visible("Available options");
+			visible.add(desc);
+			std::cout << "Usage: " << PROGRAM_NAME << " [options...] <url> <xpath>\n";
+			std::cout << visible;
+			return true;
+		}
+		else if (parVarMap.count("version")) {
+			std::cout << g_version_string;
+			std::cout << " git revision " << VERSION_GIT << "\n";
+			return true;
+		}
+
+		if (parVarMap.count("input-url") == 0) {
+			std::cerr << "No input url specified, use --help for help" << std::endl;
+			//return 2;
+			return true;
+		}
+		if (parVarMap.count("xpath") == 0) {
+			std::cerr << "No XPath expression specified, use --help for help" << std::endl;
+			//return 2;
+			return true;
+		}
+		return false;
+	}
 } //unnamed namespace
 
 int main (int argc, char* argv[]) {
-	if (argc != 3) {
+	po::variables_map vm;
-		std::cerr << PROGRAM_NAME << "v" << VERSION_MAJOR << "." << VERSION_MINOR;
+	if (parse_commandline(argc, argv, vm)) {
-#if VERSION_BETA
+		return 0;
-		std::cerr << "b";
-#endif
-		std::cerr << " git revision " << VERSION_GIT << "\n";
-		std::cerr << "Default user agent is \"" << DEFAULT_USER_AGENT << "\"\n";
-		std::cerr << "Usage: scraper <URL> <XPath>" << std::endl;
-		return 2;
 	}
-
+	const auto url = vm["input-url"].as<std::string>();
-	const char* const& url = argv[1];
+	const auto xpath = vm["xpath"].as<std::string>();
-	const char* const& xpath = argv[2];
+#if !defined(NDEBUG)
-
 	std::cout << "URL  : " << url << "\n";
 	std::cout << "XPath: " << xpath << std::endl;
+#endif
 
-	std::string tidyHtml = duck::getCleanHtml(url, false, false);
+	std::string tidyHtml = duck::getCleanHtml(vm["input-url"].as<std::string>(), false, false);
 
 	{
 		pugi::xml_document doc;
@@ -45,7 +97,7 @@ int main (int argc, char* argv[]) {
 			return 1;
 		}
 
-		pugi::xpath_node_set xpathRes = doc.select_nodes(xpath);
+		pugi::xpath_node_set xpathRes = doc.select_nodes(xpath.c_str());
 		for (pugi::xpath_node_set::const_iterator itFind(xpathRes.begin()), itFindEND(xpathRes.end()); itFind != itFindEND; ++itFind) {
 			const pugi::xpath_node& node = *itFind;
 			if (node.node()) {