備份系統設定且紀錄差異

為了玩玩在 shell script 使用函式功能, 寫了一隻簡單的程式碼紀錄系統設定的差異. 不過增加項目還是需要修改程式碼. 暫時先能用再來看如何修改.
程式碼:

#!/usr/local/bin/bash

BasePath="/PATH/TO/BACKUP/DIRECTORY"
PATH=$PATH

BackupConfig(){
if [ -z $1 ]
# Checks if any params.
then
 echo "No parameters passed to function."
 return 0
else
 ProgName=$1
fi

if [ $2 ]
then
 BackupFolder=$2
fi

case $ProgName in
postfix) CMD="postconf -n"
  ;;
sysctl)  CMD="sysctl -a"
  ;;
pkglist) CMD="ls /var/db/pkg"
  ;;
*)  echo "Do not support this program $ProgName"
                ;;
esac

mkdir -p $BasePath/$BackupFolder
rm -f $BasePath/$BackupFolder/${ProgName}_old.txt

echo "Check if had OLD data : "
if [ -f $BasePath/$BackupFolder/${ProgName}_now.txt ]; then
 echo "   Had OLD data! Rename it to ${ProgName}_old.txt"
 mv $BasePath/$BackupFolder/${ProgName}_now.txt $BasePath/$BackupFolder/${ProgName}_old.txt
else
 echo "   Do not have OLD data."
fi

echo "Backup configuration of ${ProgName} now."
$CMD > $BasePath/$BackupFolder/${ProgName}_now.txt

echo "Generate diff log : "
if [ -f $BasePath/$BackupFolder/${ProgName}_old.txt ]; then
 echo "   Generate diff log between ${ProgName}_new.txt and ${ProgName}_old.txt."
 diff $BasePath/$BackupFolder/${ProgName}_now.txt $BasePath/$BackupFolder/${ProgName}_old.txt > $BasePath/$BackupFolder/diff-`date +"%Y%m%d"`.txt
 find  $BasePath/$BackupFolder/ -type f -size 0 | xargs rm -f
else
 echo "   Do not have OLD data."
fi

}


### Backup postfix setting
BackupConfig postfix postfix_config_backup

### Backup sysctl setting
BackupConfig sysctl sysctl_config_backup

### Backup /var/db/pkg
BackupConfig pkglist installed-pkglist