Corrected an issue observed on OSX

include/ncconfigure.h

@@ -16,7 +16,7 @@
 
 /*
 This is included in bottom
-of config.h. It is where, 
+of config.h. It is where,
 typically, alternatives to
 missing functions should be
 defined and missing types defined.
@@ -42,8 +42,15 @@ typedef SSIZE_T ssize_t;
 #ifndef _WIN32
 #if __STDC__ == 1 /*supposed to be same as -ansi flag */
 extern char* strdup(const char*);
+
+#ifndef strlcat
 extern size_t strlcat(char*,const char*,size_t);
-extern int snprintf(char*, size_t, const char*, ...); 
+#endif
+
+#ifndef snprintf
+extern int snprintf(char*, size_t, const char*, ...);
+#endif
+
 extern int strcasecmp(const char*, const char*);
 extern long long int strtoll(const char*, char**, int);
 extern unsigned long long int strtoull(const char*, char**, int);

libdap4/ezxml.c

@@ -33,8 +33,9 @@
 #endif
 #include "ezxml.h"
 
-extern int vsnprintf(char*, size_t, const char*, va_list ap); 
-
+#ifndef vsnprintf
+extern int vsnprintf(char*, size_t, const char*, va_list ap);
+#endif
 
 #define EZXML_WS   "\t\r\n "  /* whitespace*/
 #define EZXML_ERRL 128        /* maximum error string length*/

ncgen/generr.c

@@ -7,7 +7,9 @@
 #include "includes.h"
 #include <ctype.h>	/* for isprint() */
 
-extern int vsnprintf(char*, size_t, const char*, va_list ap); 
+#ifndef vsnprintf
+extern int vsnprintf(char*, size_t, const char*, va_list ap);
+#endif
 
 int error_count;