Conway

doc/makedefs.6

@@ -188,6 +188,13 @@ to be "undefined."
 .I Symbol
 must already be known to
 .BR makedefs .
+.br
+.TP
+.BI --grep-test " symbol"
+Test if the
+.I symbol
+is defined.  Exit silently (unless an error occurs) with status EXIT_SUCCESS if defined,
+otherwise with status EXIT_FAILURE.
 .SH MDGREP FUNCTIONS
 The
 .B --grep