sc_handler

#!/bin/sh

# MIT License:
#
# Copyright (c) 2017, Alexander I. Chebykin
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.


# Shadow copy script
####################

# Begin of default settings block
#################################

# Directory where shadow copies will be placed
shadow_dir=/var/shadow_copies/$USER/Documents

# Directory with source files
source_dir=$(xdg-user-dir DOCUMENTS)

# Snapshot owner
owner=$USER

# Snapshot group
group=root

# Snapshot directories mask
dirs_mask=755

# Snapshot files mask
files_mask=460

# Files time to live in days
file_ttl=1

# Maximum stored file copies
max_copies=5

# Compress algorithm: 7z, tar, tar.gz, tar.bz, zip, none
compress_alg=none

# Files extentions controlled by script
extensions=( dia doc docx dot dps dpt et ett lyx odt ods pot potm potx pps ppsm ppsx ppt pptm pptx rtf txt wps xls xlsx xlt xltx xlsm
	     bash c cpp cproject h inc mk project properties xml
	     lfm lpi lpr lps pas res
	     css htm html js php
	     bmp gif jpg jpeg png psd tif tiff wmf xcf
	     sh3d
	     sql )

# End of default settings block
###############################

for param in "$@"
do
    prm=$(echo $param | cut -f1 -d=)
    val=$(echo $param | cut -f2 -d=)
    if [ $prm == "--max_copies" ]; then
	max_copies=$val
    elif [ $prm == "--shadow_dir" ]; then
	shadow_dir=$val
    elif [ $prm == "--source_dir" ]; then
	source_dir=$val
    elif [ $prm == "--owner" ]; then
	owner=$val
    elif [ $prm == "--group" ]; then
	group=$val
    elif [ $prm == "--dirs_mask" ]; then
	dirs_mask=$val
    elif [ $prm == "--files_mask" ]; then
	files_mask=$val
    elif [ $prm == "--file_ttl" ]; then
	file_ttl=$val
    elif [ $prm == "--max_copies" ]; then
	max_copies=$val
    elif [ $prm == "--compress_alg" ]; then
	compress_alg=$val
    elif [ $prm == "--help" ]; then
	echo "Usage: sc_handler [OPTIONS]"
	echo ""
	echo "--source_dir=path"
	echo "                 directory with source files"
	echo "--shadow_dir=path"
	echo "                 directory with snapshots"
	echo "--owner=owner"
	echo "                 snapshots owner"
	echo "--group=group"
	echo "                 snapshots group"
	echo "--dirs_mask=mask"
	echo "                 snapshot directories rights mask"
	echo "--files_mask=mask"
	echo "                 snapshot files mask"
	echo "--file_ttl=days"
	echo "                 snapshot files time to live in days"
	echo "--max_copies=n"
	echo "                 maximum stored snapshots of single file"
	echo "--compress_alg=7z|tar|tar.gz|tar.bz|zip|none"
	echo "                 compress algorithm"
	echo ""
	echo "Dafault values are:"
	echo "--source_dir:    $source_dir"
	echo "--shadow_dir:    $shadow_dir"
	echo "--owner:         $owner"
	echo "--group:         $group"
	echo "--dirs_mask:     $dirs_mask"
	echo "--files_mask:    $files_mask"
	echo "--file_ttl:      $file_ttl"
	echo "--max_copies:    $max_copies"
	echo "--compress_alg:  $compress_alg"
	exit
    fi
done

echo "Started with settings:"
echo "--source_dir:    $source_dir"
echo "--shadow_dir:    $shadow_dir"
echo "--owner:         $owner"
echo "--group:         $group"
echo "--dirs_mask:     $dirs_mask"
echo "--files_mask:    $files_mask"
echo "--file_ttl:      $file_ttl"
echo "--max_copies:    $max_copies"
echo "--compress_alg:  $compress_alg"

inotifywait -m -r -e modify -e create -e delete -e move --format "%w%f" "$source_dir" | while read "file"
do
    # filename in lower case
    file_lc="${file,,}"
    # file extension
    file_ext="${file_lc##*.}"

    for i in "${extensions[@]}"
    do
	if [ "$file_ext" == "$i" ]; then
	    source_file="${file##*/}"
	    source_file_dir="${file%/*}"
	    source_file_dir_len=${#source_dir}
	    file_dir="${source_file_dir:source_file_dir_len}"
	    timestamp=$(date +%Y%m%d_%H%M%S)
	    if [ -f "$file" ]; then
		mkdir -p "$shadow_dir$file_dir"
		chown $owner:$group "$shadow_dir$file_dir"
		chmod $dirs_mask "$shadow_dir$file_dir"
		if [  "$compress_alg" == "7z" ]; then
		    arch_ext=".7z"
		    7z a -mx7 -y "$shadow_dir$file_dir/$source_file.$timestamp$arch_ext" "$source_file_dir/$source_file"
		elif [  "$compress_alg" == "tar" ]; then
		    arch_ext=".tar"
		    tar -cf "$shadow_dir$file_dir/$source_file.$timestamp$arch_ext" "$source_file_dir/$source_file"
		elif [  "$compress_alg" == "tar.gz" ]; then
		    arch_ext=".tar.gz"
		    tar -czf "$shadow_dir$file_dir/$source_file.$timestamp$arch_ext" "$source_file_dir/$source_file"
		elif [  "$compress_alg" == "tar.bz" ]; then
		    arch_ext=".tar.bz"
		    tar -cjf "$shadow_dir$file_dir/$source_file.$timestamp$arch_ext" "$source_file_dir/$source_file"
		elif [  "$compress_alg" == "zip" ]; then
		    arch_ext=".zip"
		    zip "$shadow_dir$file_dir/$source_file.$timestamp$arch_ext" "$source_file_dir/$source_file"
		elif [  "$compress_alg" == "none" ]; then
		    arch_ext=".$file_ext"
		    cp "$source_file_dir/$source_file" "$shadow_dir$file_dir/$source_file.$timestamp$arch_ext"
		fi
		chown $owner:$group "$shadow_dir$file_dir/$source_file.$timestamp$arch_ext"
		chmod $files_mask "$shadow_dir$file_dir/$source_file.$timestamp$arch_ext"

		# Remove overquoted snapshots
		find_mask=$(echo $shadow_dir$file_dir/$source_file.*$arch_ext | awk '{gsub(/ /,"\\ ")}8')
		let "skip_files = max_copies + 1"
		OIFS="$IFS"
		IFS=$'\n'
		find $find_mask -maxdepth 1 -type f -printf "%T@ %p\n" | sort -k 1nr | sed 's/^[^ ]* //' | tail -n +$skip_files | while read file2del
		do
		    rm "$file2del"
		    echo "file '$file2del' deleted"
		done
		IFS="$OIFS"
	    fi
	fi
    done
    find "$shadow_dir" -type f -mtime +$file_ttl -delete 
    find "$shadow_dir" -type d -empty -delete
done