前段时间写的使用python脚本自动备份系统文件，今天来写一个使用shell脚本增量备份系统文件，顺便复习一下shell脚本相关的命令，这个脚本可以根据自己的需求来备份不同的文件或者文件夹，进行完整备份和增量备份。直接上脚本如下：

#!/bin/sh#Automatic Backup Linux System Files#Author wugk 2013-11-22#Define VariableSOURCE_DIR=(    $*)TARGET_DIR=/data/backup/YEAR=`date +%Y`MONTH=`date +%m`DAY=`date +%d`WEEK=`date +%u`FILES=system_backup.tgzCODE=$?if    [ -z "$*" ];then    echo -e "Please Enter Your Backup Files or Directories\n--------------------------------------------\nExample $0 /boot /etc ......"    exitfi#Determine Whether the Target Directory Existsif    [ ! -d $TARGET_DIR/$YEAR/$MONTH/$DAY ];then    mkdir -p $TARGET_DIR/$YEAR/$MONTH/$DAY    echo "This $TARGET_DIR is Created Successfully !"fi#EXEC Full_Backup Function CommandFull_Backup(){if    [ "$WEEK" -eq "7" ];then    rm -rf $TARGET_DIR/snapshot    cd $TARGET_DIR/$YEAR/$MONTH/$DAY ;tar -g $TARGET_DIR/snapshot -czvf $FILES `echo ${SOURCE_DIR[@]}`    [ "$CODE" == "0" ]&&echo -e  "--------------------------------------------\nThese Full_Backup System Files Backup Successfully !"fi}#Perform incremental BACKUP Function CommandAdd_Backup(){   cd $TARGET_DIR/$YEAR/$MONTH/$DAY ;if    [ -f $TARGET_DIR/$YEAR/$MONTH/$DAY/$FILES ];then    read -p "These $FILES Already Exists, overwrite confirmation yes or no ? : " SURE    if [ $SURE == "no" -o $SURE == "n" ];then    sleep 1 ;exit 0    fi#Add_Backup Files System    if        [ $WEEK -ne "7" ];then        cd $TARGET_DIR/$YEAR/$MONTH/$DAY ;tar -g $TARGET_DIR/snapshot -czvf $$_$FILES `echo ${SOURCE_DIR[@]}`        [ "$CODE" == "0" ]&&echo -e  "-----------------------------------------\nThese Add_Backup System Files Backup Successfully !"   fielse   if      [ $WEEK -ne "7" ];then      cd $TARGET_DIR/$YEAR/$MONTH/$DAY ;tar -g $TARGET_DIR/snapshot -czvf $FILES `echo ${SOURCE_DIR[@]}`      [ "$CODE" == "0" ]&&echo -e  "-------------------------------------------\nThese Add_Backup System Files Backup Successfully !"   fifi}Full_Backup;Add_Backup

以上脚本仅供参考，还有很多需要优化、完善和调整的地方，欢迎大家提出意见。