Restarted the production of the app

libs/CLI11/book/code/geet.cpp

@@ -0,0 +1,50 @@
+#include "CLI/CLI.hpp"
+
+#include <iostream>
+
+int main(int argc, char **argv) {
+
+    /// [Intro]
+    CLI::App app{"Geet, a command line git lookalike that does nothing"};
+    app.require_subcommand(1);
+    /// [Intro]
+
+    /// [Add]
+    auto add = app.add_subcommand("add", "Add file(s)");
+
+    bool add_update;
+    add->add_flag("-u,--update", add_update, "Add updated files only");
+
+    std::vector<std::string> add_files;
+    add->add_option("files", add_files, "Files to add");
+
+    add->callback([&]() {
+        std::cout << "Adding:";
+        if(add_files.empty()) {
+            if(add_update)
+                std::cout << " all updated files";
+            else
+                std::cout << " all files";
+        } else {
+            for(auto file : add_files)
+                std::cout << " " << file;
+        }
+    });
+    /// [Add]
+
+    /// [Commit]
+    auto commit = app.add_subcommand("commit", "Commit files");
+
+    std::string commit_message;
+    commit->add_option("-m,--message", commit_message, "A message")->required();
+
+    commit->callback([&]() { std::cout << "Commit message: " << commit_message; });
+    /// [Commit]
+
+    /// [Parse]
+    CLI11_PARSE(app, argc, argv);
+
+    std::cout << "\nThanks for using geet!\n" << std::endl;
+    return 0;
+    /// [Parse]
+}