--- wjoye-tkblt-2c9ea39/tests/base.tcl.orig	2020-12-23 15:04:39.019700892 +0100
+++ wjoye-tkblt-2c9ea39/tests/base.tcl	2020-12-23 15:05:40.210926839 +0100
@@ -1,4 +1,5 @@
 package require tkblt
+wm withdraw .
 
 #set sleep 1000
 set sleep 500
@@ -6,6 +7,8 @@
     set dops 0
 }
 
+puts "\n*** Press <Enter> in the console to move through test steps ***\n"
+
 proc bltPlot {w title} {
     toplevel $w
     wm title $w $title
@@ -30,7 +33,7 @@
     update
     if {$dops} {
 	$graph postscript output foo.ps
-	exec open /Applications/Preview.app/ foo.ps
+#	exec open /Applications/Preview.app/ foo.ps
     }
     after $sleep
 #    read stdin 1
@@ -48,7 +51,7 @@
     update
     if {$dops} {
 	$graph postscript output foo.ps
-	exec open /Applications/Preview.app/ foo.ps
+#	exec open /Applications/Preview.app/ foo.ps
     }
     after $sleep
 #    read stdin 1
@@ -66,7 +69,7 @@
     update
     if {$dops} {
 	$graph postscript output foo.ps
-	exec open /Applications/Preview.app/ foo.ps
+#	exec open /Applications/Preview.app/ foo.ps
     }
     after $sleep
 #    read stdin 1
--- wjoye-tkblt-2c9ea39/tests/all.tcl.orig	2020-12-23 15:05:54.351210135 +0100
+++ wjoye-tkblt-2c9ea39/tests/all.tcl	2020-12-23 15:06:18.701701481 +0100
@@ -1,3 +1,4 @@
+#!/usr/bin/tclsh
 source linegraph.tcl
 source lineelement.tcl
 source linepen.tcl