syntactically correct c code always a plus
diff --git a/src/cmd/vac/vac.c b/src/cmd/vac/vac.c
index fbb4a51..01626ce 100644
--- a/src/cmd/vac/vac.c
+++ b/src/cmd/vac/vac.c
@@ -686,7 +686,7 @@
 	VacDir dir;
 	uvlong max;
 
-	if((p=strrchr(sname, '.') == nil || strcmp(p, ".vac") != 0)
+	if((p=strrchr(sname, '.')) == nil || strcmp(p, ".vac") != 0)
 		return -1;
 
 	d = nil;