ubuntu16.04 python3.6 caffe(CPU) 配置记录

女爷i 2022-05-15 09:59 84阅读 0赞

# 转载： #

# ubuntu16.04 python3.6 caffe(CPU) 配置记录 #

[https://www.jianshu.com/p/5afdb561ce94][https_www.jianshu.com_p_5afdb561ce94]

[https://blog.csdn.net/cracker\_zhou/article/details/52682128][https_blog.csdn.net_cracker_zhou_article_details_52682128]

2018.05.18 21:36 字数 4062 阅读 1104评论 0喜欢 3

从头开始配置编译python3.6版本的caffe整整花了10天时间,期间经历了很多事,所以状态一直很差,真正的配置时间应该在五天左右.

目前搜索到的caffe配置版本多数是2.7和3.5,关于python3.6的配置基本没有.但是目前anaconda3用的python版本为3.6,tensorflow最新使用的都是3.6,所以我电脑里存在的就是3.6版本.所以我决定配置python3.6版本的caffe.

step by step!

## 1,配置opencv 3.4.1  ##

我们需要达到的目标是在python3中可以直接使用import cv2,其中关于编译这方面的资料很多.主要分为编译本体库,以及编译一个附加下载的库.但是在编译完成之后发现,依然无法成功import cv2.程序中的Import cv2提示no modules named cv2错误

解决方法:sudo pip3 install opencv-python.注意这里一定要用pip3,之前一直有资料说用pip,这样是无法成功的.使用pip3后,直接成功.

## 2,编译caffe ##

这里的大前提是已经编译配置好anaconda3,python的版本为3.6.python3.6的bin和lib文件全部在anaconda3中.

这里主要参考的是这篇博文.https://blog.csdn.net/isuccess88/article/details/70165726,但也有很多不同,他那篇是针对python3.5的.

### 2.1 安装依赖 ###

sudo apt-get install libprotobuf-dev libleveldb-dev libsnappy-dev libopencv-dev libhdf5-serial-dev protobuf-compiler

sudo apt-get install --no-install-recommends libboost-all-dev

sudo apt-get install libatlas-base-dev

sudo apt-get install libhdf5-serial-dev

sudo apt-get install libgflags-dev libgoogle-glog-dev liblmdb-dev

然后把CAFFE的源代码下载下来: git clone https://github.com/BVLC/caffe.git

(当然没有安装GIT的得先安装一下)

下载完成之后,进入CAFFE文件夹, 进入里面的PYTHON文件夹,然后输入

for req in $(cat requirements.txt); do pip3 install $req; done

(PIP如果没有安装得先安装一下:sudo apt install python-pip)

注意的地方是:pip3安装的,第二点是sudo apt-get install --no-install-recommends libboost-all-dev这一条安装编译的并没有关于python3.6版本的libboost,我们需要重新编译.否则caffe无法调用成功.(怎么编译后面说)

### 2.2 安装caffe ###

到CAFFE文件夹, 使用模板写个Makefile.config. 具体就是先复制一下模板, 再改一些内容(我喜欢用EMACS).

cp Makefile.config.example Makefile.config

\-因为CPU MODE, 所以在CPU\_ONLY := 1前面的\#要去掉.

\-两个路径要改成这样:(添加后面的两个hdf5的路径, 否则编译时报hdf5错误)

\# Whatever else you find you need goes here.

INCLUDE\_DIRS := $(PYTHON\_INCLUDE) /usr/local/include**/usr/include/hdf5/serial**

LIBRARY\_DIRS := $(PYTHON\_LIB) /usr/local/lib /usr/lib**/usr/lib/x86\_64-linux-gnu/hdf5/serial**

**一份完整的python3.6配置文件.（这里黑色加粗字体的位置就是我们要做修改注意的地方）**

> \#\# Refer to http://caffe.berkeleyvision.org/installation.html
> 
> \# Contributions simplifying and improving our build system are welcome!
> 
> \# cuDNN acceleration switch (uncomment to build with cuDNN).
> 
> \# USE\_CUDNN := 1
> 
> \# CPU-only switch (uncomment to build without GPU support).
> 
> ***CPU\_ONLY := 1\#（因为我们要配置cpu版本的，所以这里把引号去掉）***
> 
> \# uncomment to disable IO dependencies and corresponding data layers
> 
> \# USE\_OPENCV := 0
> 
> \# USE\_LEVELDB := 0
> 
> \# USE\_LMDB := 0
> 
> \# uncomment to allow MDB\_NOLOCK when reading LMDB files (only if necessary)
> 
> \# You should not set this flag if you will be reading LMDBs with any
> 
> \# possibility of simultaneous read and write
> 
> \# ALLOW\_LMDB\_NOLOCK := 1
> 
> \# Uncomment if you're using OpenCV 3
> 
> ***OPENCV\_VERSION := 3\#（我们的opencv是3版本的，所以这里我们把引号去掉，之前opencv3已经安装并编译成功）***
> 
> \# To customize your choice of compiler, uncomment and set the following.
> 
> \# N.B. the default for Linux is g++ and the default for OSX is clang++
> 
> \# CUSTOM\_CXX := g++
> 
> \# CUDA directory contains bin/ and lib/ directories that we need.
> 
> CUDA\_DIR := /usr/local/cuda
> 
> \# On Ubuntu 14.04, if cuda tools are installed via
> 
> \# "sudo apt-get install nvidia-cuda-toolkit" then use this instead:
> 
> \# CUDA\_DIR := /usr
> 
> \# CUDA architecture setting: going with all of them.
> 
> \# For CUDA < 6.0, comment the \*\_50 through \*\_61 lines for compatibility.
> 
> \# For CUDA < 8.0, comment the \*\_60 and \*\_61 lines for compatibility.
> 
> \# For CUDA >= 9.0, comment the \*\_20 and \*\_21 lines for compatibility.
> 
> CUDA\_ARCH := -gencode arch=compute\_20,code=sm\_20 \\
> 
> \-gencode arch=compute\_20,code=sm\_21 \\
> 
> \-gencode arch=compute\_30,code=sm\_30 \\
> 
> \-gencode arch=compute\_35,code=sm\_35 \\
> 
> \-gencode arch=compute\_50,code=sm\_50 \\
> 
> \-gencode arch=compute\_52,code=sm\_52 \\
> 
> \-gencode arch=compute\_60,code=sm\_60 \\
> 
> \-gencode arch=compute\_61,code=sm\_61 \\
> 
> \-gencode arch=compute\_61,code=compute\_61
> 
> \# BLAS choice:
> 
> \# atlas for ATLAS (default)
> 
> \# mkl for MKL
> 
> \# open for OpenBlas
> 
> BLAS := atlas
> 
> \# Custom (MKL/ATLAS/OpenBLAS) include and lib directories.
> 
> \# Leave commented to accept the defaults for your choice of BLAS
> 
> \# (which should work)!
> 
> \# BLAS\_INCLUDE := /path/to/your/blas
> 
> \# BLAS\_LIB := /path/to/your/blas
> 
> \# Homebrew puts openblas in a directory that is not on the standard search path
> 
> \# BLAS\_INCLUDE := $(shell brew --prefix openblas)/include
> 
> \# BLAS\_LIB := $(shell brew --prefix openblas)/lib
> 
> \# This is required only if you will compile the matlab interface.
> 
> \# MATLAB directory should contain the mex binary in /bin.
> 
> \# MATLAB\_DIR := /usr/local
> 
> \# MATLAB\_DIR := /Applications/MATLAB\_R2012b.app
> 
> \# NOTE: this is required only if you will compile the python interface.
> 
> \# We need to be able to find Python.h and numpy/arrayobject.h.
> 
> \#PYTHON\_INCLUDE := /usr/include/python2.7 \\
> 
> \# /usr/lib/python2.7/dist-packages/numpy/core/include
> 
> \# Anaconda Python distribution is quite popular. Include path:
> 
> \# Verify anaconda location, sometimes it's in root.
> 
> ***ANACONDA\_HOME := $(HOME)/anaconda3\#（我们使用的python3.6版本在anaconda3中，所以这里要取消注释，修改为你的根目录位置）***
> 
> ***PYTHON\_INCLUDE := $(ANACONDA\_HOME)/include \\***
> 
> ***$(ANACONDA\_HOME)/include/python3.6m \\\#（这两个目录要看具体anaconda3中目录的名字，我做了对应修改）***
> 
> ***$(ANACONDA\_HOME)/lib/python3.6/site-packages/numpy/core/include***
> 
> \# Uncomment to use Python 3 (default is Python 2)
> 
>   ***PYTHON\_LIBRARIES := boost\_python3 python3.6m\#（这里我取消了注释，并且修改了内容，重新编译boost python3，后面讲）***
> 
> \# PYTHON\_INCLUDE := /usr/include/python3.5m \\
> 
> \#                /usr/lib/python3.5/dist-packages/numpy/core/include
> 
> \# We need to be able to find libpythonX.X.so or .dylib.
> 
> ***\#PYTHON\_LIB := /usr/lib\#（把这里注释掉）***
> 
> ***PYTHON\_LIB := $(ANACONDA\_HOME)/lib\#（修改为我这里的位置）***
> 
> \# Homebrew installs numpy in a non standard path (keg only)
> 
> \# PYTHON\_INCLUDE += $(dir $(shell python -c 'import numpy.core; print(numpy.core.\_\_file\_\_)'))/include
> 
> \# PYTHON\_LIB += $(shell brew --prefix numpy)/lib
> 
> \# Uncomment to support layers written in Python (will link against Python libs)
> 
> \# WITH\_PYTHON\_LAYER := 1
> 
> \# Whatever else you find you need goes here.
> 
> ***INCLUDE\_DIRS := $(PYTHON\_INCLUDE) /usr/local/include  /usr/include/hdf5/serial***
> 
> ***LIBRARY\_DIRS := $(PYTHON\_LIB) /usr/local/lib /usr/lib /usr/lib/x86\_64-linux-gnu/hdf5/serial***
> 
> \# If Homebrew is installed at a non standard location (for example your home directory) and you use it for general dependencies
> 
> \# INCLUDE\_DIRS += $(shell brew --prefix)/include
> 
> \# LIBRARY\_DIRS += $(shell brew --prefix)/lib
> 
> \# NCCL acceleration switch (uncomment to build with NCCL)
> 
> \# https://github.com/NVIDIA/nccl (last tested version: v1.2.3-1+cuda8.0)
> 
> \# USE\_NCCL := 1
> 
> \# Uncomment to use \`pkg-config\` to specify OpenCV library paths.
> 
> \# (Usually not necessary -- OpenCV libraries are normally installed in one of the above $LIBRARY\_DIRS.)
> 
> \# USE\_PKG\_CONFIG := 1
> 
> \# N.B. both build and distribute dirs are cleared on \`make clean\`
> 
> BUILD\_DIR := build
> 
> DISTRIBUTE\_DIR := distribute
> 
> \# Uncomment for debugging. Does not work on OSX due to https://github.com/BVLC/caffe/issues/171
> 
> \# DEBUG := 1
> 
> \# The ID of the GPU that 'make runtest' will use to run unit tests.
> 
> TEST\_GPUID := 0
> 
> \# enable pretty build (comment to see full commands)
> 
> Q ?= @
> 
> ***LINKFLAGS := -Wl,-rpath,$(HOME)/anaconda3/lib\#（这里是由于会出现一个关于png的错误，我后面讲）***

按照流程接下来的配置应该是：

准备好了.

make pycaffe -j 4

另外, 这个make默认是用CPU单核运算,如果想要快一点, 比如我想使用四核, 在make后面加上-j4标签.

如果上面4行某一行报错之后想要重试,建议先make clean再重新开始.

如果这里出现问题，马上 make clean.

配置好了之后 ，make all

全部成功后才算是成功。

### **2.3 配置环境变量** ###

去到CAFFE文件夹里面的python文件夹, 把当前路径记录下来(pwd). 然后输入以下命令(把记下的路径放在相应地方)

export PYTHONPATH=/path/to/caffe/python:$PYTHONPATH

### 2.4 大功告成 ###

命令行中输入 python， 然后 import caffe ,基本是错的。接下来讲在编译caffe以及import caffe中出现的各种问题。

## 3.问题以及解决 ##

### 3.1 编译时候，cannot find -lboost\_python3, python3.6m ###

***原因是这一行中，PYTHON\_LIBRARIES := boost\_python3 python3.6m，首先我们boost并没有编译3.6版本，其次python3.6m这个link不在 /usr/lib 。***

***1)，sudo ln -s /home/horsetif/anaconda3/bin/python3  /usr/lib/python3.6m(这里是建立一个软链接，把我本地目录下的python3.6加到usr/lib/中去。***

***2)，编译3.6版本的libboost\_python3.so***

首先去/usr/lib/x86\_64-linux-gnu目录下查看是否有python3版本的libboost，如果有类似libboost\_python35.so但是没有libboost\_python3.so则需要手动建立连接。

方法为：

sudo ln-slibboost\_python-py35.so libboost\_python3.so

这个方法只是针对与3.5版本，现在我们重新编译，然后把编译好的结果的软链接加到/usr/lib/x86\_64-linux-gnu这个目录里面。

1.首先下载安装包，然后解压， 切换目录

> wget -O boost\_1\_67\_0.tar.gz http://sourceforge.net/projects/boost/files/boost/1.67.0/boost\_1\_67\_0.tar.gz/download  
> 
> tar xzvf boost\_1\_67\_0.tar.gz      
> 
> cd boost\_1\_67\_0/

安装包也可以在http://www.boost.org/users/history/version\_1\_67\_0.html下载

2.安装附加依赖库

> sudo apt-get update  
> 
> sudo apt-get install build-essential g++ python-dev autotools-dev libicu-dev build-essential libbz2-dev libboost-all-dev 
> 
>

linux系统自带python2.7，boost编译后会生成libboost\_python27.so，但有些应用需要libboost\_python3，下面我们就来编译。

进入boost源文件目录boost\_1\_67\_0，配置仅仅编译python，python路径指向anaconda3中的python3.6。

> ./bootstrap --with-libraries=python --with-toolset=gcc  
> 
> ./b2 --with-python include="/home/horsetif/anaconda3/include/python3.6m/"  
> 
> sudo ./b2 install

编译安装成功后，/usr/local/lib下会有libboost\_python36.so和libboost\_python36.a，有些应用link时需要的是libboost\_python3.so或者libboost\_python3.a，我们建个软链：

> cd /usr/local/lib  
> 
> sudo ln -s libboost\_python-py36.so libboost\_python3.so  
> 
> sudo ln -s libboost\_python-py36.a libboost\_python3.a

这时，我们要把/usr/local/lib 中，相关文件，建立相对于名称的软链接到 /usr/lib/x86\_64-linux-gnu中。

> sudo cp /usr/local/lib/libboost\_python36.a  /usr/lib/x86\_64-linux-gnu/libboost\_python\_python36.a
> 
> sudo cp /usr/local/lib/libboost\_python36.so.1.67.0  /usr/lib/x86\_64-linux-gnu/libboost\_python3.so

## 3.2 多个opencv问题 ##

错误：make pycaffe可以通过，但是make all时出现错误，具体错误我没有记录，但是好像是因为系统装了多个opencv的原因，不管怎么说，至少可以在python环境下import caffe了

make all时出现的错误：

.build\_release/lib/libcaffe.so: undefined reference to \`cv::imread(cv::String const&, int)'

.build\_release/lib/libcaffe.so: undefined reference to \`cv::imencode(cv::String const&, cv::\_InputArray const&, std::vector >&, std::vector > const&)'

.build\_release/lib/libcaffe.so: undefined reference to \`cv::imdecode(cv::\_InputArray const&, int)'

collect2: error: ld returned 1 exit status

Makefile:625: recipe for target '.build\_release/tools/upgrade\_net\_proto\_text.bin' failed

make: \*\*\* \[.build\_release/tools/upgrade\_net\_proto\_text.bin\] Error 1

make: \*\*\* Waiting for unfinished jobs....

解决办法：也是，的确在这之前我分别在python 3.5和python 2.7下面装了opencv，而且该教程前面又装了libopencv-dev，所以我就怀疑是这个，但是我尝试着卸载了opencv还是import出现同样的错误，最后不断找解决方案，也尝试了他们的各种解决方法，都不知道make clean然后又make all了多少次，还是不管用。最后在网站https://github.com/BVLC/caffe/issues/2348\#issuecomment-95156848看到有人说”Uncomment

***if you're using OpenCV 3”于是我在配置文件中去掉 ”OPENCV\_ VERSION :=3“的注释，我又make clean，接着make all,奇迹终于出现了，上面的错误消失了,居然make all成功了。***

### 3.3 matplotlib 问题 ###

3、错误：现在可以import caffe了，但是又出现了以下错误：

>>> import caffe

Traceback (most recent call last):

File "", line 1, in

File "/home/.../Downloads/caffe-master/python/caffe/\_\_init\_\_.py", line 1, in

from .pycaffe import Net, SGDSolver, NesterovSolver, AdaGradSolver, RMSPropSolver, AdaDeltaSolver, AdamSolver, NCCL, Timer

File "/home/.../Downloads/caffe-master/python/caffe/pycaffe.py", line 15, in

import caffe.io

File "/home/..../Downloads/caffe-master/python/caffe/io.py", line 2, in

import skimage.io

File "/home/.../Downloads/yes/lib/python3.5/site-packages/skimage/io/\_\_init\_\_.py", line 15, in

reset\_plugins()

File "/home/.../Downloads/yes/lib/python3.5/site-packages/skimage/io/manage\_plugins.py", line 93, in reset\_plugins

\_load\_preferred\_plugins()

File "/home/.../Downloads/yes/lib/python3.5/site-packages/skimage/io/manage\_plugins.py", line 73, in \_load\_preferred\_plugins

\_set\_plugin(p\_type, preferred\_plugins\['all'\])

File "/home/.../Downloads/yes/lib/python3.5/site-packages/skimage/io/manage\_plugins.py", line 85, in \_set\_plugin

use\_plugin(plugin, kind=plugin\_type)

File "/home/.../Downloads/yes/lib/python3.5/site-packages/skimage/io/manage\_plugins.py", line 255, in use\_plugin

\_load(name)

File "/home/.../Downloads/yes/lib/python3.5/site-packages/skimage/io/manage\_plugins.py", line 299, in \_load

fromlist=\[modname\])

File "/home/.../Downloads/yes/lib/python3.5/site-packages/skimage/io/\_plugins/matplotlib\_plugin.py", line 3, in

import matplotlib.pyplot as plt

File "/home/.../Downloads/yes/lib/python3.5/site-packages/matplotlib/pyplot.py", line 36, in

from matplotlib.figure import Figure, figaspect

File "/home/.../Downloads/yes/lib/python3.5/site-packages/matplotlib/figure.py", line 40, in

from matplotlib.axes import Axes, SubplotBase, subplot\_class\_factory

File "/home/..../Downloads/yes/lib/python3.5/site-packages/matplotlib/axes/\_\_init\_\_.py", line 4, in

from .\_subplots import \*

File "/home/.../Downloads/yes/lib/python3.5/site-packages/matplotlib/axes/\_subplots.py", line 10, in

from matplotlib.axes.\_axes import Axes

File "/home/.../Downloads/yes/lib/python3.5/site-packages/matplotlib/axes/\_axes.py", line 23, in

import matplotlib.dates as \_  \# <-registers a date unit converter

File "/home/.../Downloads/yes/lib/python3.5/site-packages/matplotlib/dates.py", line 126, in

from dateutil.rrule import (rrule, MO, TU, WE, TH, FR, SA, SU, YEARLY, MONTHLY, WEEKLY, DAILY, HOURLY, MINUTELY, SECONDLY)

File "/home/.../Downloads/yes/lib/python3.5/site-packages/dateutil/rrule.py", line 55

raise ValueError, "Can't create weekday with n == 0"

SyntaxError: invalid syntax

***错误解决办法：从上面可以看出也就是在  import matplotlib.pyplot as plt 时出现错误，百度了以下，尝试了几种解决方案，原来是matplotlib版本太低了，需要升级，于是我pip3 install matplotlib --upgrade 了以下，果然解决了，但是又出现了下面的问题。***

### 3.4 numpy 问题 ###

错误：Intel MKL FATAL ERROR: Cannot load libmkl\_avx.so or libmkl\_def.so.

Python 3.5.2 |Continuum Analytics, Inc.| (default, Jul  2 2016, 17:53:06)

\[GCC 4.4.7 20120313 (Red Hat 4.4.7-1)\] on linux

Type "help", "copyright", "credits" or "license" for more information.

>>> import caffe

Intel MKL FATAL ERROR: Cannot load libmkl\_avx.so or libmkl\_def.so.

解决方案：继续百度了下，哈哈，原来是因为numpy版本过低导致，于是我 ***conda update numpy ***，哈哈又成功了。。所以，我的anaconda里边的包必须得升级啊，里边的包都还是安装anaconda时系统自带的，太老了。

### 3.5 错误信息 ###

### //home/idc/anaconda3/lib/libpng16.so.16: undefined reference to \`inflateValidate@ZLIB\_1.2.9' ###

后面还有几行，主要是这个。

我的解决方法是在Makefile.config加入下列信息：

***LINKFLAGS := -Wl,-rpath,$(HOME)/anaconda3/lib***

### ***3.6 错误信息*** ###

可能会出现下面的错误：

Failed to include caffe\_pb2, things might go wrong!

Traceback (most recent call last):

File "", line 1, in

File "/home/david/download/caffe-master/python/caffe/\_\_init\_\_.py", line 4, in

from .proto.caffe\_pb2 import TRAIN, TEST

File "/home/david/download/caffe-master/python/caffe/proto/caffe\_pb2.py", line 7, in

from google.protobuf import reflection as \_reflection

File "/home/david/opt/anaconda3/lib/python3.5/site-packages/google/protobuf/reflection.py", line 68, in

from google.protobuf.internal import python\_message

File "/home/david/opt/anaconda3/lib/python3.5/site-packages/google/protobuf/internal/python\_message.py", line 848

except struct.error, e:

SyntaxError: invalid syntax

***这是因为 protobuf 不支持 python3，解决方案是安装pip install protobuf-py3, 一个 python3.x 版本的替代包。‘’***

## ***4.错误代码总汇：*** ##

***opencv 配置问题***

> ***make all***
> 
> ***.build\_release/lib/libcaffe.so: undefined reference to \`cv::imencode(cv::String const&, cv::\_InputArray const&, std::vector>&, std::vector > const&)'***
> 
> .build\_release/lib/libcaffe.so: undefined reference to \`cv::imdecode(cv::\_InputArray const&, int)'
> 
> collect2: error: ld returned 1 exit status
> 
> Makefile:625: recipe for target '.build\_release/tools/compute\_image\_mean.bin' failed
> 
> make: \*\*\* \[.build\_release/tools/compute\_image\_mean.bin\] Error 1

python版本与编译caffe版本问题

> from .\_caffe import Net, SGDSolver, NesterovSolver, AdaGradSolver, \\
> 
> ImportError: /home/horsetif/Software/caffe/python/caffe/../../build/lib/libcaffe.so.1.0.0: undefined symbol: \_ZN2cv6imreadERKNS\_6StringEi
> 
>  
> 
> File "/home/horsetif/Software/caffe/python/caffe/pycaffe.py", line 13, in from .\_caffe import Net, SGDSolver, NesterovSolver, AdaGradSolver, \\
> 
> ImportError: dynamic module does not define module export function (PyInit\_\_caffe)

boost 配置问题

> CXX/LD -o python/caffe/\_caffe.so python/caffe/\_caffe.cpp
> 
> /usr/bin/ld: cannot find -lboost\_python3
> 
> collect2: error: ld returned 1 exit status
> 
> Makefile:507: recipe for target 'python/caffe/\_caffe.so' failed
> 
> make: \*\*\* \[python/caffe/\_caffe.so\] Error 1

boost修改好了之后没有放对位置

> File "/home/horsetif/Software/caffe/python/caffe/pycaffe.py", line 13, in from .\_caffe import Net, SGDSolver, NesterovSolver, AdaGradSolver, \\
> 
> ImportError: libboost\_python36.so.1.67.0: cannot open shared object file: No such file or directory
> 
>

matplotlib 问题

> from matplotlib.axes.\_axes import Axes File "/home/horsetif/anaconda3/lib/python3.6/site-packages/matplotlib/axes/\_axes.py", line 23, inimport matplotlib.dates as \_ \# <-registers a date unit converter File "/home/horsetif/anaconda3/lib/python3.6/site-packages/matplotlib/dates.py", line 148, in from dateutil.rrule import (rrule, MO, TU, WE, TH, FR, SA, SU, YEARLY,
> 
>   File "/home/horsetif/anaconda3/lib/python3.6/site-packages/dateutil/rrule.py", line 55
> 
>     raise ValueError, "Can't create weekday with n == 0"
> 
>                     ^
> 
> SyntaxError: invalid syntax

[https_www.jianshu.com_p_5afdb561ce94]: https://www.jianshu.com/p/5afdb561ce94
[https_blog.csdn.net_cracker_zhou_article_details_52682128]: https://blog.csdn.net/cracker_zhou/article/details/52682128