--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/shells/tcsh/tcsh-post.sh	Tue Sep 03 13:53:14 2019 +0200
@@ -0,0 +1,24 @@
+#!/bin/busybox sh
+#
+# Copyright (c) 2019 David Demelier <markand@malikania.fr>
+#
+# Permission to use, copy, modify, and/or distribute this software for any
+# purpose with or without fee is hereby granted, provided that the above
+# copyright notice and this permission notice appear in all copies.
+#
+# THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+# WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+# MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+# ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+# WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+# ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+# OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+#
+
+if [ "$1" = "post-install" ]; then
+	if ! grep -q "/bin/tcsh" /etc/shells >/dev/null 2>&1; then
+		echo "/bin/tcsh" >> /etc/shells
+	fi
+elif [ "$1" = "post-uninstall" ]; then
+	sed -i -e '/\/bin\/tcsh/d' /etc/shells
+fi