Example solution for C++ 101 Exercise 1 (command-line arguments)

base/cpp101/hello_world.cc

Index: base/cpp101/hello_world.cc
diff --git a/base/cpp101/hello_world.cc b/base/cpp101/hello_world.cc
index eb0940ef582d0c901af358a632e65dd3eca7f348..771a7ec27ca2ac756d9e3cc82967f1f3dcdb1e15 100644
--- a/base/cpp101/hello_world.cc
+++ b/base/cpp101/hello_world.cc
@@ -4,10 +4,23 @@
 
 #include <stdio.h>
 
+#include <string>
+
+#include "base/command_line.h"
 #include "base/logging.h"
 
 int main(int argc, char* argv[]) {
-  CHECK_GT(puts("Hello, world!"), 0);
-  LOG(INFO) << "Hello, logging!";
+  CHECK(CommandLine::Init(argc, argv));
+
+  const CommandLine& command_line = *CommandLine::ForCurrentProcess();
+  std::string greeting = command_line.GetSwitchValueASCII("greeting");
+  if (greeting.empty())
+    greeting = "Hello";
+  std::string name = command_line.GetSwitchValueASCII("name");
+  if (name.empty())
+    name = "world";
+
+  CHECK_GT(printf("%s, %s!\n", greeting.c_str(), name.c_str()), 0);
+  LOG(INFO) << greeting << ", " << name << "!";
   return 0;
 }