我们经常使用rm去删除一些文件，如果不小手一抖，那么就悲剧了，你们都懂的。。。

在经历过一次这样的惨剧后，决定永远杜绝这种情况，重写写了shell函数，执行安全的rm。这个函数会把要删除的文件按日期备份到指定的目录，同时根据删除时间的不同会有多个版本，同时提供了另外一个函数用于恢复之前删除的文件。

# safe rm
# Don‘t remove the file, just move them to a temporary directory.
# Files are grouped by remove time.
# e.g.
#   # pwd => /home/work/
#   > rm -r -f aa
#   ‘aa‘ will move to ~/.TrashHistory/20141018/aa@120111@_home_work_aa
RM_BACKUP_PATH=/Users/louzhenlin/.TrashHistory
function safe_rm() {
    # skip cmd option, e.g. ‘-rf‘ in ‘rm -rf a b‘ or ‘-r/-f‘ in ‘rm -r -f a b‘
    first_char=${1:0:1}
    until [ ! "$first_char" = "-" ]
    do
        shift
        first_char=${1:0:1}
    done

    # check param
    if [ $# -lt 1 ]; then
        echo ‘usage: rm [-f | -i] [-dPRrvW] file ...‘
        exit 1
    fi

    today=`date +"%Y%m%d"`
    mvpath=${RM_BACKUP_PATH}/$today

    # support for multi version
    timestamp=`date +"%H%M%S"`

    # create dir if path non-exist
    if [ ! -d $mvpath ]; then
        mkdir $mvpath
    fi

    until [ $# -eq 0 ]
    do
        # fetch absolute path of the file
        fpath=$1
        fchar=`echo "${fpath:0:1}"`
        if [ "$fchar" = "/" ]; then
            dist_path="_${fpath}"
        else
            abs_fpath=`pwd`/$fpath
            dist_path="${fpath}@${timestamp}@${abs_fpath}"
        fi

        # substitue ‘/‘ to ‘_‘
        final_dist_path=${dist_path//\//_}

        # mv to temp trash
        mv $fpath $mvpath/$final_dist_path

        # next file
        shift
    done
}

?  ~  ll ~/.TrashHistory/20141021
total 32
drwxr-xr-x  7 louzhenlin  staff  238 10 21 18:01 .
drwxr-xr-x  5 louzhenlin  staff  170 10 21 15:51 ..
-rw-r--r--  1 louzhenlin  staff  136 10 20 23:39 a@180117@_Users_louzhenlin_dev_workspace_c_cpp_leveldb_a
-rw-r--r--  1 louzhenlin  staff  399 10 14 17:43 aof.log@164609@_Users_louzhenlin_dev_workspace_python_redis_aof_modifer_aof.log
-rw-r--r--  1 louzhenlin  staff    0 10 14 11:19 appendonly-1.aof@155727@_Users_louzhenlin_dev_server_redis-2.8.17_appendonly-1.aof
-rw-r--r--  1 louzhenlin  staff  399 10 14 17:42 appendonly.aof@155105@_Users_louzhenlin_dev_server_redis-2.8.17_appendonly.aof
-rw-r--r--  1 louzhenlin  staff  565 10 21 15:56 appendonly.aof@161315@_Users_louzhenlin_dev_server_redis-2.8.17_appendonly.aof

# revert files that remove by safe_rm
# you can choose the right one in multi files removed
function revert_rm() {
    cd $RM_BACKUP_PATH

    # process multi files
    until [ $# -eq 0 ]
    do
        echo "revert for $1:"
        for f in `find . -name "$1@*" -print`
        do
            d=`echo $f | awk -F\/ ‘{print $2}‘`
            t=`echo $f | awk -F@ ‘{print $2}‘`
            fpath=`echo $f | awk -F@ ‘{print $3}‘`
            fpath=${fpath//_/\/}

            echo -n "      $fpath at ${d:0:4}-${d:4:2}-${d:6:2} ${t:0:2}:${t:2:2}:${t:4:2}   [y/n]? "
            read confirm
            if [ "${confirm}" = ‘y‘ ]; then
                mv $f $fpath
                break
            fi
        done

        shift
    done
}

?  ~  revert_rm appendonly.aof
revert for appendonly.aof:
      /Users/louzhenlin/dev/server/redis-2.8.17/appendonly.aof at 2014-10-21 15:51:05   [y/n]? n
      /Users/louzhenlin/dev/server/redis-2.8.17/appendonly.aof at 2014-10-21 16:13:15   [y/n]? y

可恢复的安全rm