首先建立50万个文件

test  for i in $(seq 1 500000)
for> do
for> echo test >>$i.txt
for> done

1. rm

test  time rm -f *
zsh: sure you want to delete all the files in /home/hungerr/test [yn]? y
zsh: argument list too long: rm
rm -f *  3.63s user 0.29s system 98% cpu 3.985 total

由于文件数量过多，rm不起作用

 

2. find

test  time find ./ -type f -exec rm {} \;
find ./ -type f -exec rm {} \;  49.86s user 1032.13s system 41% cpu 43:19.17 total

大概43分钟。

 

3. find with delete

test  time find ./ -type f -delete       
find ./ -type f -delete  0.43s user 11.21s system 2% cpu 9:13.38 total

用时9分钟。

 

4. rsync

首先建立空文件夹blanktest，注意这个通常用来快速清空整个文件夹而不是单独删文件

~  time rsync -a --delete blanktest/ test/
rsync -a --delete blanktest/ test/  0.59s user 7.86s system 51% cpu 16.418 total

16s，很好很强大。关于它为什么这么快，参考 https://liulantao.com/why-can-rsync-rapidly-delete-400000-files.html

 

5. Python

import os
import time
stime=time.time()
for pathname,dirnames,filenames in os.walk('/home/username/test'):
     for filename in filenames:
         file=os.path.join(pathname,filename)
         os.remove(file)
 ftime=time.time()
 print ftime-stime

执行python脚本

~  python test.py
494.272291183

大概用时8分钟。

 

6. Perl

 test  time perl -e 'for(<*>){((stat)[9]<(unlink))}'
perl -e 'for(<*>){((stat)[9]<(unlink))}'  1.28s user 7.23s system 50% cpu 16.784 tota