From: Ben Hutchings <ben@decadent.org.uk>
Date: Sun, 27 Nov 2005 21:47:30 +0000 (+0000)
Subject: Added --help option and arranged to print usage information when this is used and... 
X-Git-Tag: 0.3~3
X-Git-Url: https://git.decadent.org.uk/gitweb/?a=commitdiff_plain;h=a144f37803d6e86aedd634e971d8a76b0d8ac5fa;p=videolink.git

Added --help option and arranged to print usage information when this is used and in (almost) all cases of bad usage.
---

diff --git a/webdvd.cpp b/webdvd.cpp
index a6064b2..94ab121 100644
--- a/webdvd.cpp
+++ b/webdvd.cpp
@@ -867,23 +867,40 @@ namespace
 	    std::string("Invalid video standard: ").append(str));
     }
 
+    void print_usage(std::ostream & stream, const char * command_name)
+    {
+	stream << "Usage: " << command_name
+	       << (" [gtk-options] [--video-std std-name]"
+		   " front-page-url output-dir\n");
+    }
+    
 } // namespace
 
 int main(int argc, char ** argv)
 {
     try
     {
-	// Determine video frame parameters.
+	// Do initial argument parsing.  We have to do this before
+	// letting Gtk parse the arguments since we need to spawn Xvfb
+	// first and that's currently dependent on the frame
+	// parameters (though we could just make it large enough for
+	// any frame) and also an unnecessary expense in some cases.
 	video::frame_params frame_params = video::pal_params;
 	for (int argi = 1; argi != argc; ++argi)
 	{
 	    if (std::strcmp(argv[argi], "--") == 0)
 		break;
+	    if (std::strcmp(argv[argi], "--help") == 0)
+	    {
+		print_usage(std::cout, argv[0]);
+		return EXIT_SUCCESS;
+	    }
 	    if (std::strcmp(argv[argi], "--video-std") == 0)
 	    {
 		if (argi + 1 == argc)
 		{
 		    std::cerr << "Missing argument to --video-std\n";
+		    print_usage(std::cerr, argv[0]);
 		    return EXIT_FAILURE;
 		}
 		frame_params = lookup_frame_params(argv[argi + 1]);
@@ -901,9 +918,7 @@ int main(int argc, char ** argv)
 	// Initialise Gtk
 	Gtk::Main kit(argc, argv);
 
-	// Check we have the right number of arguments.  We can't
-	// do this earlier because we need to let Gtk read and remove
-	// any of the many options it understands.
+	// Complete argument parsing with Gtk's options out of the way.
 	int argi = 1;
 	while (argi != argc)
 	{
@@ -919,6 +934,7 @@ int main(int argc, char ** argv)
 	    else if (argv[argi][0] == '-')
 	    {
 		std::cerr << "Invalid option: " << argv[argi] << "\n";
+		print_usage(std::cerr, argv[0]);
 		return EXIT_FAILURE;
 	    }
 	    else
@@ -926,9 +942,7 @@ int main(int argc, char ** argv)
 	}
 	if (argi != argc - 2)
 	{
-	    std::cerr << "Usage: " << argv[0]
-		      << (" [gtk-options] [--video-std std-name]"
-			  "front-page-url output-dir\n");
+	    print_usage(std::cerr, argv[0]);
 	    return EXIT_FAILURE;
 	}