1、新建百万个文件

for i in $(seq 1 1000000)
do
  echo test >>$i.txt
done

2、常规方法

test  time rm -f *
zsh: sure you want to delete all the files in /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

3、find

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

4、find+delete

time find ./ -type f -delete      
find ./ -type f -delete  0.43suser 11.21s system 2% cpu 9:13.38 total
用时9分钟。

5、rsync（建议）

首先建立空文件夹blanktest
rsync -a --deleteblanktest/ test/
rsync -a --delete blanktest/ test/  0.59suser 7.86s system 51% cpu 16.418 total 
16s，很好很强大。

6、python

import os
import time
stime=time.time()
for pathname,dirnames,filenames inos.walk('/home/username/test'):
     for filename in filenames:
         file=os.path.join(pathname,filename)
         os.remove(file)
 ftime=time.time()
 printftime-stime
 python test.py
494.272291183
大概用时8分钟

7、perl

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