--- gpl/axl/knife/exarg.c	2011/06/08 07:09:12	1.1.1.1
+++ gpl/axl/knife/exarg.c	2012/02/17 12:50:02	1.1.1.2
@@ -1,4 +1,4 @@
-/**
+/** 
  *  LibExploreArguments: a library to parse command line options
  *  Copyright (C) 2005 Advanced Software Production Line, S.L.
  * 
@@ -451,11 +451,6 @@ char     ** exarg_split           (const char * chunk,
 }
 
 /** 
- * @internal Proto-type declaration to avoid gcc complaining.
- */
-int vsnprintf(char *str, size_t size, const char *format, va_list ap);
-
-/** 
  * @internal Allows to calculate the amount of memory required to
  * store the string that will representing the construction provided
  * by the printf-like format received and its arguments.
@@ -513,21 +508,21 @@ int exarg_vprintf_len (const char * format, va_list ar
  */
 char  * exarg_strdup_printfv    (char * chunk, va_list args)
 {
-	/** IMPLEMENTATION NOTE: place update axl_stream_printf_buffer
+	/** IMPLEMENTATION NOTE: place update axl_stream_strdup_printfv
 	 * code in the case this code is updated **/
 
 #ifndef HAVE_VASPRINTF
 	int       size;
 #endif
 	char    * result   = NULL;
-	int       new_size = -1;
 
 	if (chunk == NULL)
 		return NULL;
 
 #ifdef HAVE_VASPRINTF
 	/* do the operation using the GNU extension */
-	new_size = vasprintf (&result, chunk, args);
+	if (vasprintf (&result, chunk, args) == -1)
+		return NULL;
 #else
 	/* get the amount of memory to be allocated */
 	size = exarg_vprintf_len (chunk, args);
@@ -542,12 +537,12 @@ char  * exarg_strdup_printfv    (char * chunk, va_list
 	result   = exarg_new (char, size + 2);
 	
 	/* copy current size */
-#if defined(OS_WIN32) && ! defined (__GNUC__)
-	new_size = _vsnprintf_s (result, size + 1, size, chunk, args);
-#else
-	new_size = vsnprintf (result, size + 1, chunk, args);
+#  if defined(OS_WIN32) && ! defined (__GNUC__)
+	_vsnprintf_s (result, size + 1, size, chunk, args);
+#  else
+	vsnprintf (result, size + 1, chunk, args);
+#  endif
 #endif
-#endif
 	/* return the result */
 	return result;
 }
@@ -895,7 +890,7 @@ void exarg_show_usage (int show_header)
 	ExArgNodeOption * node;
 	
 	if (show_header && (__exarg_usage_header && (* __exarg_usage_header)))
-		printf (__exarg_usage_header);
+		printf ("%s", __exarg_usage_header);
 
 	printf ("Usage: %s ", exarg_exec_name);
 	
@@ -917,7 +912,7 @@ void exarg_show_usage (int show_header)
 	exarg_free (string_aux);
 
 	if (show_header && (__exarg_post_usage_header && (* __exarg_post_usage_header)))
-		printf (__exarg_post_usage_header);
+		printf ("%s", __exarg_post_usage_header);
 	
 	return;
 }
@@ -1007,12 +1002,12 @@ void __exarg_show_help_foreach (epointer key, epointer
 	return;
 }
 
-void   exarg_show_help () 
+void   exarg_show_help (void) 
 {
 	ExArgNodeOption * node;
 
 	if (__exarg_help_header && (* __exarg_help_header))
-		printf (__exarg_help_header);
+		printf ("%s", __exarg_help_header);
 
 	exarg_show_usage (0);
 
@@ -1033,7 +1028,7 @@ void   exarg_show_help () 
 	printf ("  --usage                       Display brief usage message.\n");
 
 	if (__exarg_post_help_header && (* __exarg_post_help_header))
-		printf (__exarg_post_help_header);
+		printf ("%s", __exarg_post_help_header);
 
 	return;
 }
@@ -1060,7 +1055,7 @@ void exarg_check_argument_value (char ** argv, int ite
 }
 
 
-void __exarg_parse_check_non_optional ()
+void __exarg_parse_check_non_optional (void)
 {
 	ExArgNodeOption * node = argument_options;
 
@@ -1080,7 +1075,7 @@ void __exarg_parse_check_non_optional ()
 	return;
 }
 
-void __exarg_parse_check_depends ()
+void __exarg_parse_check_depends (void)
 {
 	/* first argument */
 	ExArgNodeOption * node = argument_options;
@@ -1848,8 +1843,48 @@ void       exarg_define           (char * arg_name,
 			/* string value */
 			node->string_value = value;
 			break;
-		}
+		} /* end switch */
 	} /* end if */
+
+	/* nothing to do over here */
+	return;
+}
+
+/**
+ * @brief Allows to undef the value associated and the definition
+ * itself of the option provided (arg_name).
+ *
+ * @param arg_name The argument to undef.
+ */
+void         exarg_undef            (char * arg_name)
+{
+	ExArgNodeOption * node;
+
+	/* perform some environment checks */
+	if (arg_name == NULL)
+		return;
+
+	node = exarg_lookup_node (arg_name);
+	if (node == NULL) 
+		return;
+
+	/* undef the value */
+	node->is_defined = 0;
+
+	/* check argument value */
+	switch (node->type) {
+	case EXARG_NONE:
+		/* nothing to set */
+		break;
+	case EXARG_INT:
+		/* integer value */
+		node->int_value = 0;
+		break;
+	case EXARG_STRING:
+			/* string value */
+		node->string_value = NULL;
+		break;
+	} /* end switch */
 
 	/* nothing to do over here */
 	return;