New @-code: @checkmark@, sends the Unicode CHECKMARK or the CP437

square root symbol (or PETSCII check mark), as appropriate.

src/sbbs3/atcodes.cpp

@@ -38,6 +38,7 @@
 #include "cmdshell.h"
 #include "utf8.h"
 #include "unicode.h"
+#include "cp437defs.h"
 
 #if defined(_WINSOCKAPI_)
 	extern WSADATA WSAData;
@@ -160,6 +161,11 @@ const char* sbbs_t::atcode(char* sp, char* str, size_t maxlen)
 		return nulstr;
 	}
 
+	if(strcmp(sp, "CHECKMARK") == 0) {
+		outchar(UNICODE_CHECK_MARK, CP437_CHECK_MARK);
+		return nulstr;
+	}
+
 	if(!strcmp(sp,"VER"))
 		return(VERSION);