save_cfg

#!/bin/sh
#
# Copyright (c) 2006 Mathieu Arnold
# Copyright (c) 2010 Alex Bakhtin
# Copyright (c) 2018 Portrat Benoit
# All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. 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.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``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 OR CONTRIBUTORS 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.
#
# 2018 version based on: $FreeBSD: releng/11.2/tools/tools/nanobsd/Files/root/save_cfg 309884 2016-12-12 11:02:55Z brueffer $
# 2018 vesrion adds support for symbolic links but requires rsync as a dependency.
#

set -e

trap "umount /cfg" 1 2 15 EXIT
mount /cfg
(
cd /etc
for filename in "$@" `find * -type f` `find * -type l`
do
    if [ ! -f /cfg/$filename -a ! -f /cfg/.ignore/$filename ]
    then

        #
        # If file doesn't exist in /cfg and file is not in the 'ignore' list
        # then check if this file is exactly the same as original file
        # in nanobsd image
        #
        if ! cmp -hs /etc/$filename /conf/base/etc/$filename 
        then
            file_path=`echo "$filename" | sed 's/\/[^/]*$//'`
            if [ $file_path != $filename ]
            then
                if [ ! -d /etc/$file_path ]
                then
                    # should never go here unless we have some errors in
                    # sed script extracting file path
                    echo "Error: Path /etc/$file_path is not directory."
                    exit 1;
                fi
            fi

            #
            # Ask user - how should we handle this file.
            # Add to cfg (y/n/i)?
            #    y) -> save this file in /cfg
            #    n) -> do not save this file in /cfg for current script invocation ONLY
            #    i) -> add file to ignore list (/cfg/.ignore hiereachy) and never save
            #          try to add this file to /cfg.
            #
            # touch is used to add files to /cfg to keep the script flow straight and easy
            #
            read -p "New file /etc/$filename found. Add to /cfg (y/n/i)? " key
            case "$key" in
            [yY])
                if [ $file_path != $filename ]
                then
                    mkdir -vp /cfg/$file_path
                fi
                touch /cfg/$filename && echo "File /etc/$filename added to /cfg."
                ;;
            [iI])
                mkdir -vp /cfg/.ignore
                if [ $file_path != $filename ]
                then
                    mkdir -vp /cfg/.ignore/$file_path
                fi
                touch /cfg/.ignore/$filename && echo "File /etc/$filename added to ignore list."
                ;;
            esac
        fi
    fi
done

#
# Actually check all files in /cfg and save if necessary
#
cd /cfg
for filename in "$@" `find * -type f` `find * -type l`
do
    if [ -L /etc/$filename ]
    then
        cmp -hs /etc/$filename /cfg/$filename && continue
        diff -du "/cfg/${filename}" "/etc/${filename}" || true
        read -p "File /etc/$filename modified. Persist changes in /cfg (y/n)? " key
        case "$key" in
        [yY])
            rsync --info=COPY,DEL,FLIST,MISC,NAME,SYMSAFE -lptgo /etc/$filename /cfg/$filename
            ;;
        esac
    elif [ -f /etc/$filename ]
    then
        cmp -hs /etc/$filename /cfg/$filename && continue
        diff -du "/cfg/${filename}" "/etc/${filename}" || true
        read -p "File /etc/$filename modified. Persist changes in /cfg (y/n)? " key
        case "$key" in
        [yY])
            cp -pfv /etc/$filename /cfg/$filename
            ;;
        esac
    else

        #
        # Give user an option to remove file from /cfg if this file is removed from /etc
        #
        read -p "File /cfg/$filename not found in /etc. Remove from /cfg (y/n)? " key
        case "$key" in
        [yY])
            rm /cfg/$filename && echo "File /cfg/$filename removed"
            ;;
        esac
    fi
done

)
umount /cfg
trap 1 2 15 EXIT