printing more useful message when missing required args and catching ArgException reference

include/tclap/CmdLine.h

@@ -114,6 +114,11 @@ class CmdLine : public CmdLineInterface
 		 */
 		CmdLineOutput* _output;
 
+		/**
+		 * Throws an exception listing the missing args.
+		 */
+		void missingArgsException();
+
 		/**
 		 * Checks whether a name/flag string matches entirely matches
 		 * the Arg::blankChar.  Used when multiple switches are combined
@@ -408,12 +413,12 @@ inline void CmdLine::parse(int argc, char** argv)
     }
 
 	if ( requiredCount < _numRequired )
-		throw(CmdLineParseException("One or more required arguments missing!"));
+		missingArgsException();
 
 	if ( requiredCount > _numRequired )
 		throw(CmdLineParseException("Too many arguments!"));
 
-	} catch ( ArgException e ) { _output->failure(*this,e); exit(1); }
+	} catch ( ArgException& e ) { _output->failure(*this,e); exit(1); }
 }
 
 inline bool CmdLine::_emptyCombined(const std::string& s)
@@ -428,6 +433,33 @@ inline bool CmdLine::_emptyCombined(const std::string& s)
 	return true;
 }
 
+inline void CmdLine::missingArgsException() 
+{
+		int count = 0;
+
+		std::string missingArgList;
+		for (ArgListIterator it = _argList.begin(); it != _argList.end(); it++)
+		{
+			if ( (*it)->isRequired() && !(*it)->isSet() )
+			{
+				missingArgList += (*it)->getName();
+				missingArgList += ", ";
+				count++;
+			}
+		}
+		missingArgList = missingArgList.substr(0,missingArgList.length()-2);
+		
+		std::string msg;
+		if ( count > 1 )
+			msg = "Required arguments missing: ";
+		else
+			msg = "Required argument missing: ";
+
+		msg += missingArgList;
+
+		throw(CmdLineParseException(msg));
+}
+
 inline void CmdLine::deleteOnExit(Arg* ptr)
 {
 	_argDeleteOnExitList.push_back(ptr);

tests/Makefile.am

@@ -60,7 +60,8 @@ TESTS = test1.sh \
 		test58.sh \
 		test59.sh \
 		test60.sh \
-		test61.sh
+		test61.sh \
+		test62.sh
 
 EXTRA_DIST = $(TESTS) \
 			 test1.out \
@@ -123,6 +124,7 @@ EXTRA_DIST = $(TESTS) \
 			 test58.out \
 			 test59.out \
 			 test60.out \
-			 test61.out
+			 test61.out \
+			 test62.out
 
 CLEANFILES = tmp.out

tests/test10.out

@@ -1,5 +1,5 @@
 PARSE ERROR:  
-             One or more required arguments missing!
+             Required argument missing: unTest
 
 Brief USAGE: 
    ../examples/test2  [-f <float>] -i <int> -s <string> [-A] [-C] [-B] [--]

tests/test17.out

@@ -1,5 +1,5 @@
 PARSE ERROR:  
-             One or more required arguments missing!
+             Required argument missing: unTest2
 
 Brief USAGE: 
    ../examples/test3  [-f=<float>] ...  [-i=<int>] ... 

tests/test4.out

@@ -1,5 +1,5 @@
 PARSE ERROR:  
-             One or more required arguments missing!
+             Required argument missing: name
 
 Brief USAGE: 
    ../examples/test1  [-r] -n <string> [--] [--version] [-h]

tests/test51.out

@@ -1,5 +1,5 @@
 PARSE ERROR:  
-             One or more required arguments missing!
+             Required argument missing: unTest2
 
 Brief USAGE: 
    ../examples/test8  [-f=<float>] ...  [-i=<int>] ...  -s=<string> [-B]

tests/test62.out

@@ -0,0 +1,10 @@
+PARSE ERROR:  
+             Required arguments missing: intTest, stringTest, unTest
+
+Brief USAGE: 
+   ../examples/test2  [-f <float>] -i <int> -s <string> [-A] [-C] [-B] [--]
+                      [--version] [-h] <string> <string> ...
+
+For complete USAGE and HELP type: 
+   ../examples/test2 --help
+

tests/test62.sh

@@ -0,0 +1,13 @@
+#!/bin/sh
+
+# this tests whether all required args are listed as
+# missing when no arguments are specified
+# failure  
+../examples/test2  > tmp.out 2>&1
+
+if cmp -s tmp.out $srcdir/test62.out; then
+	exit 0
+else
+	exit 1
+fi
+