Update generate_examples target with new cmake command for examples

Author: alandefreitas

test/generate_examples/main.cpp

@@ -240,7 +240,7 @@ int main() {
 
         // Enqueue all executable source files in the order defined by CMakeLists.txt
         vector<fs::path> cpps = {};
-        e = regex(R"(add_executable\([^ ]+ ([^\) ]+\.cpp)\))");
+        e = regex(R"(add_matplot_example\([^ ]+ ([^\) ]+\.cpp)\))");
         iter = sregex_iterator(cmake_content.begin(), cmake_content.end(), e);
         while (iter != sregex_iterator{}) {
             for(unsigned i = 1; i < iter->size(); ++i) {
@@ -403,15 +403,21 @@ int main() {
                 // because we might be updating the png image from a new
                 // svg we put there with this intention for some reason
                 string cmd = "rsvg-convert \"" + figure_destination_svg.string() + "\" > \"" + figure_destination_png.string() + "\"";
-                system(cmd.c_str());
+                int r = system(cmd.c_str());
+                if (r != 0) {
+                    std::cerr << "Could not execute " << cmd << std::endl;
+                }
 
                 // Create a png thumbnail as well
                 // We create the thumbnail even if it already exists
                 // because we might be updating the thumbnail from a new
                 // svg we put there with this intention for some reason
                 // rsvg-convert -h 100 filename.svg > filename-100.png
                 cmd = "rsvg-convert -h 100 \"" + figure_destination_svg.string() + "\" > \"" + figure_destination_thumbnail_png.string() + "\"";
-                system(cmd.c_str());
+                r = system(cmd.c_str());
+                if (r != 0) {
+                    std::cerr << "Could not execute " << cmd << std::endl;
+                }
 
                 // Keep only the smallest image (svg or png) for the large gallery
                 // We need to do that because some svg examples would be huge