emacs/build-aux/update-subdirs

#!/bin/sh
# Write into $1/subdirs.el a list of subdirs of directory $1.

# Copyright (C) 1994-1995, 1997, 1999, 2001-2017 Free Software
# Foundation, Inc.

# This file is part of GNU Emacs.

# GNU Emacs is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.

# GNU Emacs is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.

# You should have received a copy of the GNU General Public License
# along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.


cd "$1" || exit 1
for file in *; do
    case $file in
	*.elc | *.el | term | RCS | CVS | Old | . | .. | =* | *~ | *.orig | *.rej)
	  ;;
	*)
	    if [ -d $file ]; then
		if [ "$file" = "obsolete" ]; then
		    subdirs="$subdirs \"$file\""
		else
		    subdirs="\"$file\" $subdirs"
		fi
	    fi
	    ;;
    esac
done

if [ "x$subdirs" = x ]; then
  rm -f subdirs.el
else
  rm -f subdirs.el~
  echo ";; In load-path, after this directory should come
;; certain of its subdirectories.  Here we specify them.
(normal-top-level-add-to-load-path '($subdirs))
;; Local" "Variables:
;; version-control: never
;; no-byte-compile: t
;; no-update-autoloads: t
;; End:" > subdirs.el~
  if cmp "subdirs.el" "subdirs.el~" >/dev/null 2>&1; then
    rm subdirs.el~
  else
    mv subdirs.el~ subdirs.el
  fi
fi