Find and delete duplicate files

作用：查找指定目录（一个或多个）及子目录下的所有重复文件，分组列出，并可手动选择或自动随机删除多余重复文件，每组重复文件仅保留一份。（支持文件名有空格，例如："file  name" 等）

实现：find遍历指定目录查找所有文件，并对找到的所有文件进行MD5校验，通过比对MD5值分类处理重复文件。

不足：  find 遍历文件耗时；

MD5校验大文件耗时；

对所有文件校验比对耗时（可考虑通过比对文件大小进行第一轮的重复性筛选，此方式针对存放大量大文件的目录效果明显，本脚本未采用）；

演示：

注释：

脚本执行过程中显示MD5校验过程，完毕后，统计信息如下：

Files: 校验的文件总数

Groups: 重复文件组的数量

Size：此处统计的大小为，多余文件的总大小，即将要删除的多余的重复文件的大小，换句话说就是，删除重复文件后，磁盘空间会节省的空间。

可在“Show detailed information ?”提示后，按键“y”，进行重复文件组的查看，以便确认，也可直接跳过，进入删除文件方式的选择菜单：

删除文件方式有两种，一种是手动选择方式（默认的方式），每次列出一组重复文件，手动选择欲留下的文件，其他文件将会被删除，若没有选择 则默认保留列表的第一个文件，演示如下：

另一种方式是自动选择方式，默认保留每组文件的第一个文件，其他重复文件自动删除。（为防止删除重要文件，建议使用第一种方式），演示如下：

支持文件名空格的情况，演示如下：

代码专区：

#!/bin/bash
#Author: LingYi
#Date:
#Func: Delete duplicate files
#EG  : $ [ DIR1 DIR2 ... DIRn ]

#Define the mnt file, confirming the write authority by yourself.
md5sum_result_log="/tmp/$(date +%Y%m%d%H%M%S)"

echo -e "\033[1;31mMd5suming ...\033[0m"

 -I {} md5sum {} | tee -a $md5sum_result_log
files_sum=$(cat $md5sum_result_log | wc -l)

# Define array, using the value of md5 as index, filename as element.
# Firstly, you must do advance declaration to make sure the it's supported by bash.
declare -A md5sum_value_arry

while read md5sum_value md5sum_filename
do
    #Space in a file name, in order to support this case ，using the ‘+’ as the segmentation charater.
    #So, if '+' appears in a file name, there will be problems. The use should choose the manual mode to delete redundant files.
    md5sum_value_arry[$md5sum_value]="${md5sum_value_arry[$md5sum_value]}+$md5sum_filename"
    (( _${md5sum_value}+= ))
done <$md5sum_result_log

# counting the duplicate file groups and the size of redundant files in this loop.
groups_sum=
repfiles_size=
for md5sum_value_index in ${!md5sum_value_arry[@]}
do
     ]]; then
        let groups_sum++
        need_print_indexes="$need_print_indexes $md5sum_value_index"
        eval repfile_sum=\$\(\( \$_$md5sum_value_index -  \)\)
        repfile_size=$( ls -lS "`echo ${md5sum_value_arry[$md5sum_value_index]}|awk -F'+' '{print $2}'`" | awk '{print $5}')
        repfiles_size=$(( repfiles_size + repfile_sum*repfile_size ))
    fi
done 

#Outputing the statistical information.
echo -e "\033[1;31mFiles: $files_sum    Groups: $groups_sum    \
Size: ${repfiles_size}B $((repfiles_size/))K $((repfiles_size//))M\[0m"
[[ $groups_sum -eq  ]] && exit

#The use chooses whether to check the file grouping or not.
read -n  -s -t  -p 'Show detailed information ?' user_ch
[[ $user_ch == 'n' ]] && echo || {
    [[ $user_ch == 'q' ]] && exit
    for print_value_index in $need_print_indexes
    do
        echo -ne "\n\033[1;35m$((++i)) \033[0m"
        eval echo -ne "\\\033[1\;34m$print_value_index [ \$_${print_value_index} ]:\\\033[0m"
        echo ${md5sum_value_arry[$print_value_index]} | tr '+' '\n'
    done | more
}

#The user can choose the way of deleting file here.
echo -e "\n\nManual Selection by default !"
echo -e " 1 Manual selection\n 2 Random selection"
echo -ne "\033[1;31m"
read -t  USER_CH
echo -ne "\033[0m"
[[ $USER_CH == 'q' ]] && exit
[[ $USER_CH -ne  ]] && USER_CH= || {
    echo -ne "\033[31mWARNING: you have choiced the Random Selection mode, files will be deleted at random !\nAre you sure ?\033[0m"
    read -t   yn
    [[ $yn == 'q' ]] && exit
    [[ $yn !=
}

#Handle files according to the user's selection
echo -e "\033[31m\nWarn: keep the first file by default.\033[0m"
for exec_value_index in $need_print_indexes
do
    #This loop contains an array of files that are about to be deleted.
    ,j=;i<$(echo ${md5sum_value_arry[$exec_value_index]} | grep -o '+' | wc -l); i++,j++))
    do
        file_choices_arry[i]="$(echo ${md5sum_value_arry[$exec_value_index]}|awk -F'+' '{print $J}' J=$j)"
    done

    eval file_sum=\$_$exec_value_index
     ]]; then
        #If the user selects a manual mode, handle the duplicate file group one by one in a loop.
        echo -e "\033[1;34m$exec_value_index\033[0m"
        ; j<${#file_choices_arry[@]}; j++))
        do
            echo "[ $j ]  ${file_choices_arry[j]}"
        done
        read -p "Number of the file you want to keep: " num_ch
        [[ $num_ch == 'q' ]] && exit
         $((${#file_choices_arry[@]}-)) |
    else
        num_ch=
    fi
    #If the user selects the automatic deletion mode, then delete the redundant files
    ; n<${#file_choices_arry[@]}; n++))
    do
        [[ $n -ne $num_ch ]] && {
            echo -ne "\033[1mDeleting file \" ${file_choices_arry[n]} \" ... \033[0m"
            rm -f "${file_choices_arry[n]}"
            [[ $? -eq  ]] && echo -e "\033[1;32mOK" || echo -e "\033[1;31mFAIL"
            echo -ne "\033[0m"
        }
    done
done