add ,mkobj script to create an OBJDIR that isn't backed up

Author: bad

,mkobj

@@ -0,0 +1,20 @@
+#!/bin/sh
+#
+# ,mkobj -- make an objdir for the NetBSD build system
+#
+# usage: ,mkobj [dir]
+# Defaulting to dir to "obj".  Mark the directory as not to be backed up.
+#
+obj=${1:-obj}
+mkdir ${obj}
+
+# Mark $obj as not to be backed up.
+case $(uname -s) in
+NetBSD)
+    chflags -d nodump ${obj}
+    ;;
+Darwin)
+    tmutil addexclusion ${obj}
+    ;;
+# XXX handle Linux
+esac

README.md

@@ -29,6 +29,10 @@ command line options to simplify often used QEMU incantations.
 
 Run it with the `-h` or `--help` options to print the usage message.
 
+### ,mkobj
+Create a NetBSD build system OBJDIR (default "obj") and mark it as not to be
+backuped.
+
 ### ,yymmdd
 Outputs the current date in YYMMDD format -- shorter and
 faster to type than `date +%y%m%d`.