From a4e13e9f83918fafeffc592500d539573f3eb859 Mon Sep 17 00:00:00 2001
From: Alexander Afanasyev <alexander.afanasyev@ucla.edu>
Date: Tue, 20 Nov 2012 20:06:29 -0800
Subject: [PATCH] core: Extending public interface of CommandLine class.

Now it is possible to request printing command line arguments to the
desired output stream using PrintHelp or operator <<:

  CommandLine cmd;
  cmd.Parse (argc, argv);
...

  std::cerr << cmd;
or
  cmd.PrintHelp (std::cerr);
---
 src/core/model/command-line.cc | 92 +++++++++++++++++++++---------------------
 src/core/model/command-line.h  | 52 +++++++++++++++++++-----
 2 files changed, 88 insertions(+), 56 deletions(-)

diff --git a/src/core/model/command-line.cc b/src/core/model/command-line.cc
index 2a259ba..58ea101 100644
--- a/src/core/model/command-line.cc
+++ b/src/core/model/command-line.cc
@@ -147,17 +147,17 @@ CommandLine::Parse (int iargc, char *argv[])
 }
 
 void
-CommandLine::PrintHelp (void) const
+CommandLine::PrintHelp (std::ostream &os) const
 {
   NS_LOG_FUNCTION (this);
 
-  std::cout << m_name << " [Program Arguments] [General Arguments]"
-            << std::endl;
+  os << m_name << " [Program Arguments] [General Arguments]"
+     << std::endl;
   
   if (m_usage.length ())
     {
-      std::cout << std::endl;
-      std::cout << m_usage << std::endl;
+      os << std::endl;
+      os << m_usage << std::endl;
     }
   
   if (!m_items.empty ())
@@ -169,25 +169,25 @@ CommandLine::PrintHelp (void) const
         }
       width += 3;
 
-      std::cout << std::endl;
-      std::cout << "Program Arguments:" << std::endl;
+      os << std::endl;
+      os << "Program Arguments:" << std::endl;
       for (Items::const_iterator i = m_items.begin (); i != m_items.end (); ++i)
         {
-          std::cout << "    --"
-                    << std::left << std::setw (width) << ( (*i)->m_name + ":")
-                    << std::right
-                    << (*i)->m_help;
+          os << "    --"
+             << std::left << std::setw (width) << ( (*i)->m_name + ":")
+             << std::right
+             << (*i)->m_help;
 
           if ( (*i)->HasDefault ())
             {
-              std::cout << " [" << (*i)->GetDefault () << "]";
-            }
-          std::cout << std::endl;
-        }
+              os << " [" << (*i)->GetDefault () << "]";
+    }
+          os << std::endl;
+}
     }
 
-  std::cout << std::endl;
-  std::cout
+  os << std::endl;
+  os
     << "General Arguments:\n"
     << "    --PrintGlobals:              Print the list of globals.\n"
     << "    --PrintGroups:               Print the list of groups.\n"
@@ -199,80 +199,80 @@ CommandLine::PrintHelp (void) const
 }
 
 void
-CommandLine::PrintGlobals (void) const
+CommandLine::PrintGlobals (std::ostream &os) const
 {
   NS_LOG_FUNCTION (this);
 
-  std::cout << "Global values:" << std::endl;
+  os << "Global values:" << std::endl;
   
   for (GlobalValue::Iterator i = GlobalValue::Begin ();
        i != GlobalValue::End ();
        ++i)
     {
-      std::cout << "    --" << (*i)->GetName () << "=[";
+      os << "    --" << (*i)->GetName () << "=[";
       Ptr<const AttributeChecker> checker = (*i)->GetChecker ();
       StringValue v;
       (*i)->GetValue (v);
-      std::cout << v.Get () << "]" << std::endl;
-      std::cout << "        " << (*i)->GetHelp () << std::endl;
+      os << v.Get () << "]" << std::endl;
+      os << "        " << (*i)->GetHelp () << std::endl;
     }
 }
 
 void
-CommandLine::PrintAttributes (std::string type) const
+CommandLine::PrintAttributes (std::ostream &os, const std::string &type) const
 {
   NS_LOG_FUNCTION (this);
 
   TypeId tid;
   if (!TypeId::LookupByNameFailSafe (type, &tid))
     {
-      NS_FATAL_ERROR ("Unknown type=" << type << " in --PrintAttributes");
+      NS_FATAL_ERROR ("Unknown type="<<type<<" in --PrintAttributes");
     }
 
-  std::cout << "Attributes for TypeId " << tid.GetName () << std::endl;
+  os << "Attributes for TypeId " << tid.GetName () << std::endl;
   
   for (uint32_t i = 0; i < tid.GetAttributeN (); ++i)
     {
-      std::cout << "    --" << tid.GetAttributeFullName (i) << "=[";
+      os << "    --" << tid.GetAttributeFullName (i) << "=[";
       struct TypeId::AttributeInformation info = tid.GetAttribute (i);
-      std::cout << info.initialValue->SerializeToString (info.checker) << "]"
+      os << info.initialValue->SerializeToString (info.checker) << "]"
                 << std::endl;
-      std::cout << "        " << info.help << std::endl;
+      os << "        " << info.help << std::endl;
     }
 }
 
 
 void
-CommandLine::PrintGroup (std::string group) const
+CommandLine::PrintGroup (std::ostream &os, const std::string &group) const
 {
   NS_LOG_FUNCTION (this);
 
-  std::cout << "TypeIds in group " << group << ":" << std::endl;
+  os << "TypeIds in group " << group << ":" << std::endl;
   
   for (uint32_t i = 0; i < TypeId::GetRegisteredN (); ++i)
     {
       TypeId tid = TypeId::GetRegistered (i);
       if (tid.GetGroupName () == group)
         {
-          std::cout << "    " <<tid.GetName () << std::endl;
+          os << "    " <<tid.GetName () << std::endl;
         }
     }
 }
 
 void
-CommandLine::PrintTypeIds (void) const
+CommandLine::PrintTypeIds (std::ostream &os) const
 {
   NS_LOG_FUNCTION (this);
-  std::cout << "Registered TypeIds:" << std::endl;
+  os << "Registered TypeIds:" << std::endl;
   for (uint32_t i = 0; i < TypeId::GetRegisteredN (); ++i)
     {
       TypeId tid = TypeId::GetRegistered (i);
-      std::cout << "    " << tid.GetName () << std::endl;
+      os << "    " << tid.GetName () << std::endl;
     }
 }
 
 void
-CommandLine::PrintGroups (void) const
+CommandLine::PrintGroups (std::ostream &os) const
 {
   NS_LOG_FUNCTION (this);
 
@@ -302,56 +302,56 @@ CommandLine::PrintGroups (void) const
         }
     }
   
-  std::cout << "Registered TypeId groups:" << std::endl;
+  os << "Registered TypeId groups:" << std::endl;
   
   for (std::list<std::string>::const_iterator k = groups.begin ();
        k != groups.end ();
        ++k)
     {
-      std::cout << "    " << *k << std::endl;
+      os << "    " << *k << std::endl;
     }
 }
 
 void
-CommandLine::HandleArgument (std::string name, std::string value) const
+CommandLine::HandleArgument (const std::string &name, const std::string &value) const
 {
   NS_LOG_FUNCTION (this << name << value);
 
-  NS_LOG_DEBUG ("Handle arg name=" << name << " value=" << value);
+  NS_LOG_DEBUG ("Handle arg name="<<name<<" value="<<value);
   if (name == "PrintHelp" || name == "help")
     {
       // method below never returns.
-      PrintHelp ();
+      PrintHelp (std::cout);
       std::exit (0);
     } 
   else if (name == "PrintGroups")
     {
       // method below never returns.
-      PrintGroups ();
+      PrintGroups (std::cout);
       std::exit (0);
     }
   else if (name == "PrintTypeIds")
     {
       // method below never returns.
-      PrintTypeIds ();
+      PrintTypeIds (std::cout);
       std::exit (0);
     }
   else if (name == "PrintGlobals")
     {
       // method below never returns.
-      PrintGlobals ();
+      PrintGlobals (std::cout);
       std::exit (0);
     }
   else if (name == "PrintGroup")
     {
       // method below never returns.
-      PrintGroup (value);
+      PrintGroup (std::cout, value);
       std::exit (0);
     }
   else if (name == "PrintAttributes")
     {
       // method below never returns.
-      PrintAttributes (value);
+      PrintAttributes (std::cout, value);
       std::exit (0);
     }
   else
@@ -378,7 +378,7 @@ CommandLine::HandleArgument (std::string name, std::string value) const
     {
       std::cerr << "Invalid command-line arguments: --"
                 << name << "=" << value << std::endl;
-      PrintHelp ();
+      PrintHelp (std::cerr);
       std::exit (1);
     }
 }
diff --git a/src/core/model/command-line.h b/src/core/model/command-line.h
index ba13248..009cac7 100644
--- a/src/core/model/command-line.h
+++ b/src/core/model/command-line.h
@@ -203,6 +203,22 @@ public:
    */
   std::string GetName () const;
 
+  /**
+   * \brief Print program usage to the desired output stream
+   *
+   * Handler for \c \-\-PrintHelp and \c \-\-help:  print Usage(), argument names, and help strings
+   *
+   * Alternatively, an overloaded operator << can be used:
+   * @code
+   *       CommandLine cmd;
+   *       cmd.Parse (argc, argv);
+   *     ...
+   *
+   *       std::cerr << cmd;
+   * @endcode
+   */
+  void PrintHelp (std::ostream &os) const;
+
 private:
 
   /**
@@ -279,29 +295,25 @@ private:
    * \param name the argument name
    * \param value the command line value
    */
-  void HandleArgument (std::string name, std::string value) const;
-  /**
-   * Handler for \c \-\-PrintHelp and \c \-\-help:  print Usage(), argument names, and help strings
-   */
-  void PrintHelp (void) const;
+  void HandleArgument (const std::string &name, const std::string &value) const;
   /** Handler for \c \-\-PrintGlobals:  print all global variables and values */
-  void PrintGlobals (void) const;
+  void PrintGlobals (std::ostream &os) const;
   /**
    * Handler for \c \-\-PrintAttributes:  print the attributes for a given type.
    *
    * \param type the TypeId whose Attributes should be displayed
    */
-  void PrintAttributes (std::string type) const;
+  void PrintAttributes (std::ostream &os, const std::string &type) const;
   /**
    * Handler for \c \-\-PrintGroup:  print all types belonging to a given group.
    *
    * \param group the name of the TypeId group to display
    */
-  void PrintGroup (std::string group) const;
+  void PrintGroup (std::ostream &os, const std::string &group) const;
   /** Handler for \c \-\-PrintTypeIds:  print all TypeId names. */
-  void PrintTypeIds (void) const;
+  void PrintTypeIds (std::ostream &os) const;
   /** Handler for \c \-\-PrintGroups:  print all TypeId group names */
-  void PrintGroups (void) const;
+  void PrintGroups (std::ostream &os) const;
   /**
    * Copy constructor
    *
@@ -399,6 +411,26 @@ CommandLineHelper::UserItemParse (const std::string value, T & val)
   return !iss.bad () && !iss.fail ();
 }
 
+/**
+ * \brief Overloaded operator << to print program usage (shortcut for CommandLine::PrintHelper)
+ * \see CommandLine::PrintHelper
+ *
+ * Example usage:
+ * @code
+ *       CommandLine cmd;
+ *       cmd.Parse (argc, argv);
+ *       ...
+ *
+ *       std::cerr << cmd;
+ * @endcode
+ */
+inline std::ostream &
+operator << (std::ostream &os, const CommandLine &cmd)
+{
+  cmd.PrintHelp (os);
+  return os;
+}
+
 } // namespace ns3
 
 #endif /* COMMAND_LINE_H */
-- 
1.8.3.3