use macro for /usr/local/plan9
diff --git a/man/man4/9pserve.4 b/man/man4/9pserve.4
index 81cfc26..510c16e 100644
--- a/man/man4/9pserve.4
+++ b/man/man4/9pserve.4
@@ -43,4 +43,4 @@
.IR intro (4),
.IR intro (9p)
.SH SOURCE
-.B /usr/local/plan9/src/cmd/9pserve.c
+.B \*9/src/cmd/9pserve.c
diff --git a/man/man4/acme.4 b/man/man4/acme.4
index f6a4853..7d5f248 100644
--- a/man/man4/acme.4
+++ b/man/man4/acme.4
@@ -400,7 +400,7 @@
.B tag
is always appended; the file offset is ignored.
.SH SOURCE
-.B /usr/local/plan9/src/cmd/acme
+.B \*9/src/cmd/acme
.SH SEE ALSO
.IR rio (1),
.IR acme (1)
diff --git a/man/man4/plumber.4 b/man/man4/plumber.4
index 681bd5e..95259a0 100644
--- a/man/man4/plumber.4
+++ b/man/man4/plumber.4
@@ -101,7 +101,7 @@
.B /usr/$user/lib/plumbing
default rules file
.TP
-.B /usr/local/plan9/plumb
+.B \*9/plumb
directory to search for files in
.B include
statements
@@ -110,7 +110,7 @@
mount name for
.IR plumber (4).
.SH SOURCE
-.B /usr/local/plan9/src/cmd/plumb
+.B \*9/src/cmd/plumb
.SH "SEE ALSO"
.IR plumb (1),
.IR plumb (3),
diff --git a/man/man4/ramfs.4 b/man/man4/ramfs.4
index 32405de..25ae4bf 100644
--- a/man/man4/ramfs.4
+++ b/man/man4/ramfs.4
@@ -44,7 +44,7 @@
to write a user-level file server.
It can also be used to provide high-performance temporary files.
.SH SOURCE
-.B /usr/local/plan9/src/cmd/ramfs.c
+.B \*9/src/cmd/ramfs.c
.SH "SEE ALSO"
.IR 9p (3),
.IR 9pserve (4)
