crontab 备份且屏蔽crontab -r命令

source ~/.bashrc

etime=`date -d "0 days ago" +%Y%m%d_%H%M%S`

if [ "$1" = "-r" ] ; then
    echo "你别乱删除"
    echo "还好没有生效,下次注意别乱使用crontab -r"
    exit 2
fi

if [ "$1" = "-l" ] ; then
    /usr/bin/crontab -l
    exit 0
fi

if [ "$1" = "-e" ] ; then
    mkdir -p  ~/cronbak
    /usr/bin/crontab -l  >  ~/crontab_bak/$etime.a
    /usr/bin/crontab -e
    /usr/bin/crontab -l  >  ~/crontab_bak/$etime.b
fi

注意:其他人要重进linux才生效