Index: license_text_tmp.txt
===================================================================
--- license_text_tmp.txt	(revision 8624d1fcfcb2bdfbaacc3e871d8ca6d70dc72384)
+++ license_text_tmp.txt	(revision e49d0ac5c74cd60bb0ab8f98eccdf2530d53c93f)
@@ -1,2 +1,3 @@
+#!/bin/sh
 #
 # All rights reserved.
Index: tools/build-ccheck.sh
===================================================================
--- tools/build-ccheck.sh	(revision 8624d1fcfcb2bdfbaacc3e871d8ca6d70dc72384)
+++ tools/build-ccheck.sh	(revision e49d0ac5c74cd60bb0ab8f98eccdf2530d53c93f)
@@ -1,29 +1,7 @@
 #!/bin/sh
 #
-# Copyright (c) 2021 Jiri Svoboda
-# All rights reserved.
+# SPDX-FileCopyrightText: 2021 Jiri Svoboda
 #
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions
-# are met:
-#
-# - Redistributions of source code must retain the above copyright
-#   notice, this list of conditions and the following disclaimer.
-# - Redistributions in binary form must reproduce the above copyright
-#   notice, this list of conditions and the following disclaimer in the
-#   documentation and/or other materials provided with the distribution.
-# - The name of the author may not be used to endorse or promote products
-#   derived from this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
-# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
-# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
-# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
-# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
-# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
-# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# SPDX-License-Identifier: BSD-3-Clause
 #
 
Index: tools/ccheck.sh
===================================================================
--- tools/ccheck.sh	(revision 8624d1fcfcb2bdfbaacc3e871d8ca6d70dc72384)
+++ tools/ccheck.sh	(revision e49d0ac5c74cd60bb0ab8f98eccdf2530d53c93f)
@@ -1,29 +1,7 @@
 #!/bin/sh
 #
-# Copyright (c) 2018 Jiri Svoboda
-# All rights reserved.
+# SPDX-FileCopyrightText: 2018 Jiri Svoboda
 #
-# Redistribution and use in source and binary forms, with or without
-# modification, are permitted provided that the following conditions
-# are met:
-#
-# - Redistributions of source code must retain the above copyright
-#   notice, this list of conditions and the following disclaimer.
-# - Redistributions in binary form must reproduce the above copyright
-#   notice, this list of conditions and the following disclaimer in the
-#   documentation and/or other materials provided with the distribution.
-# - The name of the author may not be used to endorse or promote products
-#   derived from this software without specific prior written permission.
-#
-# THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
-# IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
-# OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
-# IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
-# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
-# NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
-# DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
-# THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
-# (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
-# THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+# SPDX-License-Identifier: BSD-3-Clause
 #
 
Index: tools/transform-copyright.sh
===================================================================
--- tools/transform-copyright.sh	(revision 8624d1fcfcb2bdfbaacc3e871d8ca6d70dc72384)
+++ tools/transform-copyright.sh	(revision e49d0ac5c74cd60bb0ab8f98eccdf2530d53c93f)
@@ -7,9 +7,10 @@
 grep -F '# Copyright' $FILENAME > $FILENAME.copyright__
 grep -v -F '# Copyright' $FILENAME > $FILENAME.nocopyright__
-head -n 26 $FILENAME.nocopyright__ > $FILENAME.license__
+head -n 27 $FILENAME.nocopyright__ > $FILENAME.license__
 
 if diff -q $FILENAME.license__ license_text_tmp.txt; then
-	tail -n +27 $FILENAME.nocopyright__ > $FILENAME.nolicense__
-	echo "#" > $FILENAME
+	tail -n +28 $FILENAME.nocopyright__ > $FILENAME.nolicense__
+	echo '#!/bin/sh' > $FILENAME
+	echo "#" >> $FILENAME
 	sed 's/Copyright (c)/SPDX-FileCopyrightText:/g' $FILENAME.copyright__ >> $FILENAME
 	echo "#" >> $FILENAME