From 88e702e6be62d486b0238806aac204c0b608693f Mon Sep 17 00:00:00 2001
From: iansun2 <iansun2004@gmail.com>
Date: Tue, 15 Nov 2022 10:42:16 +0800
Subject: [PATCH] diff

---
 diff_backup.sh | 138 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 138 insertions(+)
 create mode 100755 diff_backup.sh

diff --git a/diff_backup.sh b/diff_backup.sh
new file mode 100755
index 0000000..6def152
--- /dev/null
+++ b/diff_backup.sh
@@ -0,0 +1,138 @@
+#!/bin/bash
+
+
+#full
+full() {
+	echo "[full]"
+	
+	#mark running
+	touch ${dst_dir}/running
+
+	#max_backups must >= 2
+	[ $max_backups -lt 2 ] && max_backups=2 
+	
+	#get old_backups
+	old_backups=$(ls ${dst_dir}/full | wc -l)
+	echo "!$old_backups!"
+
+	#delete old backups to max_backups-1
+	while [ ${old_backups} -ge ${max_backups} ]
+	do
+		oldest_dir=$(ls ${dst_dir}/full | sort -n | head -n 1) #find oldest dir by name
+		rm -r ${dst_dir}/full/${oldest_dir}
+		rm -r ${dst_dir}/diff/${oldest_dir}
+		echo "remove ${oldest_dir}"
+		old_backups=$((old_backups-1))
+	done
+	
+	#create new backup dir
+	mkdir ${dst_dir}/full/$(date +"%F")
+	mkdir ${dst_dir}/diff/$(date +"%F")
+	
+	rsync -av $src_dir ${dst_dir}/full/$(date +"%F")/
+
+	rm ${dst_dir}/running
+}
+
+
+#diff
+diff() {
+	echo "[diff]"
+
+	#mark running
+	touch ${dst_dir}/running
+
+	#max_backups must >= 2
+	[ $max_backups -lt 2 ] && max_backups=2 
+	
+	#find newest full dir by name
+	newest_full=$(ls ${dst_dir}/full | sort -rn | head -n 1) 
+
+	#get old_backups
+	old_backups=$(ls ${dst_dir}/diff/${newest_full} | wc -l)
+	echo "!$old_backups!"
+
+	#delete old backups to max_backups-1
+	while [ ${old_backups} -ge ${max_backups} ]
+	do
+		oldest_dir=$(ls ${dst_dir}/diff/${newest_full} | sort -n | head -n 1) #find oldest dir by name
+		rm -r ${dst_dir}/diff/${newest_full}/${oldest_dir}
+		echo "remove ${oldest_dir}"
+		old_backups=$((old_backups-1))
+	done
+	
+	#create new backup dir
+	mkdir ${dst_dir}/diff/${newest_full}/$(date +"%F_T%H")
+	
+	rsync -av $src_dir ${dst_dir}/diff/${newest_full}/$(date +"%F_T%H")/ --link-dest=../../../full/${newest_full}/
+
+	rm ${dst_dir}/running
+
+}
+
+
+#init
+init() {
+	echo "[init]"
+
+	#check src_dir readable
+	[ ! -r $src_dir ] && echo "src_dir cannot read"
+
+	#check dst_dir writeable
+	if [ ! -w $dst_dir ]; then
+		echo "dst_dir cannot write"
+	else
+		#create needed dir
+		mkdir ${dst_dir}/full
+		mkdir ${dst_dir}/diff
+		echo "init ok"
+	fi
+}
+
+
+#------------main-------------#
+
+#assign arg to var
+src_dir=$3
+dst_dir=$4
+mode=$1
+max_backups=$2
+
+#check init only
+if [[ $src_dir == "" ]] || [[ $dst_dir == "" ]] ; then
+	echo no src_dir or dst_dir input
+	exit 1
+fi
+
+#set src_dir end without /
+if [[ $src_dir == */ ]]; then
+	src_dir=${src_dir%?}
+fi
+#set dst_dir end without /
+if [[ $dst_dir == */ ]]; then
+	dst_dir=${dst_dir%?}
+fi
+
+#input debug
+#echo "$mode $src_dir $dst_dir"
+
+#check if other processing running
+if [ -f ${dst_dir}/running ]; then
+	echo "other processing running"
+	exit 2
+fi
+
+#mode
+if [ $mode == "full" ]; then
+	full
+elif [ $mode == "diff" ]; then
+	diff
+elif [ $mode == "init" ]; then
+	init
+else
+	echo "no mode select"
+	#exit 4
+fi
+
+#debug
+#echo $(ls ${dst_dir}/full | sort -n | head -n 1)