use macro for /usr/local/plan9
diff --git a/man/man1/scat.1 b/man/man1/scat.1
index 8840c1d..f5ee897 100644
--- a/man/man1/scat.1
+++ b/man/man1/scat.1
@@ -322,7 +322,7 @@
 .SH FILES
 .B /lib/sky/*.scat
 .SH SOURCE
-.B /usr/local/plan9/src/cmd/scat
+.B \*9/src/cmd/scat
 .SH SEE ALSO
 .IR astro (1)
 .br