From: Mikko Rasa <tdb@tdb.fi>
Date: Thu, 7 May 2009 06:01:55 +0000 (+0000)
Subject: Improve GetOpt help generation
X-Git-Tag: 1.1~4
X-Git-Url: http://git.tdb.fi/?p=libs%2Fcore.git;a=commitdiff_plain;h=c76bd823b81d723d8cd4531631a4b18544f1981a

Improve GetOpt help generation
---

diff --git a/source/core/getopt.cpp b/source/core/getopt.cpp
index b8e2413..8fd13a0 100644
--- a/source/core/getopt.cpp
+++ b/source/core/getopt.cpp
@@ -37,18 +37,18 @@ string GetOpt::generate_usage(const string &argv0) const
 			if(!(*i)->get_long().empty())
 				line<<'|';
 			else if((*i)->get_arg_type()==OPTIONAL_ARG)
-				line<<"[ARG]";
+				line<<'['<<(*i)->get_metavar()<<']';
 			else if((*i)->get_arg_type()==REQUIRED_ARG)
-				line<<" ARG";
+				line<<' '<<(*i)->get_metavar();
 		}
 		if(!(*i)->get_long().empty())
 		{
 			line<<"--"<<(*i)->get_long();
 
 			if((*i)->get_arg_type()==OPTIONAL_ARG)
-				line<<"[=ARG]";
+				line<<"[="<<(*i)->get_metavar()<<']';
 			else if((*i)->get_arg_type()==REQUIRED_ARG)
-				line<<"=ARG";
+				line<<'='<<(*i)->get_metavar();
 		}
 		line<<']';
 	}
@@ -62,34 +62,48 @@ The returned string will have a linefeed at the end.
 */
 string GetOpt::generate_help() const
 {
-	string result;
+	bool any_short=false;
+	for(list<OptBase *>::const_iterator i=opts.begin(); (!any_short && i!=opts.end()); ++i)
+		any_short=(*i)->get_short();
+
+	unsigned maxw=0;
+	list<string> switches;
 	for(list<OptBase *>::const_iterator i=opts.begin(); i!=opts.end(); ++i)
 	{
-		ostringstream line;
-		line<<"  ";
+		ostringstream swtch;
 		if((*i)->get_short())
 		{
-			line<<'-'<<(*i)->get_short();
+			swtch<<'-'<<(*i)->get_short();
 			if(!(*i)->get_long().empty())
-				line<<", ";
+				swtch<<", ";
 			else if((*i)->get_arg_type()==OPTIONAL_ARG)
-				line<<"[ARG]";
+				swtch<<'['<<(*i)->get_metavar()<<']';
 			else if((*i)->get_arg_type()==REQUIRED_ARG)
-				line<<" ARG";
+				swtch<<' '<<(*i)->get_metavar();
 		}
+		else if(any_short)
+			swtch<<"    ";
 		if(!(*i)->get_long().empty())
 		{
-			line<<"--"<<(*i)->get_long();
+			swtch<<"--"<<(*i)->get_long();
 
 			if((*i)->get_arg_type()==OPTIONAL_ARG)
-				line<<"[=ARG]";
+				swtch<<"[="<<(*i)->get_metavar()<<']';
 			else if((*i)->get_arg_type()==REQUIRED_ARG)
-				line<<"=ARG";
+				swtch<<'='<<(*i)->get_metavar();
 		}
+		switches.push_back(swtch.str());
+		maxw=max(maxw, switches.back().size());
+	}
 
-		line<<"  "<<(*i)->get_help()<<'\n';
-
-		result+=line.str();
+	string result;
+	list<string>::const_iterator j=switches.begin();
+	for(list<OptBase *>::const_iterator i=opts.begin(); i!=opts.end(); ++i, ++j)
+	{
+		result+="  "+*j;
+		result+=string(maxw+2-j->size(), ' ');
+		result+=(*i)->get_help();
+		result+='\n';
 	}
 	
 	return result;
@@ -211,4 +225,26 @@ unsigned GetOpt::process_short(const char *const *argp)
 	return 1;
 }
 
+
+GetOpt::OptBase::OptBase(char s, const std::string &l, ArgType a):
+	shrt(s),
+	lng(l),
+	arg_type(a),
+	seen_count(0),
+	metavar("ARG")
+{ }
+
+GetOpt::OptBase &GetOpt::OptBase::set_help(const string &h)
+{
+	help=h;
+	return *this;
+}
+
+GetOpt::OptBase &GetOpt::OptBase::set_help(const string &h, const string &m)
+{
+	help=h;
+	metavar=m;
+	return *this;
+}
+
 } // namespace Msp
diff --git a/source/core/getopt.h b/source/core/getopt.h
index 7e5e25f..f6c4859 100644
--- a/source/core/getopt.h
+++ b/source/core/getopt.h
@@ -27,11 +27,13 @@ public:
 	class OptBase
 	{
 	public:
-		OptBase           &set_help(const std::string &h) { help=h; return *this; }
+		OptBase           &set_help(const std::string &);
+		OptBase           &set_help(const std::string &, const std::string &);
 		char              get_short() const               { return shrt; }
 		const std::string &get_long() const               { return lng; }
 		ArgType           get_arg_type() const            { return arg_type; }
 		const std::string &get_help() const               { return help; }
+		const std::string &get_metavar() const            { return metavar; }
 		unsigned          get_seen_count() const          { return seen_count; }
 		virtual void      process()=0;
 		virtual void      process(const std::string &)=0;
@@ -42,8 +44,9 @@ public:
 		ArgType     arg_type;
 		unsigned    seen_count;
 		std::string help;
+		std::string metavar;
 
-		OptBase(char s, const std::string &l, ArgType a): shrt(s), lng(l), arg_type(a), seen_count(0) { }
+		OptBase(char, const std::string &, ArgType);
 	};
 
 private: