Python3学习之路~9.1 paramiko模块：实现ssh执行命令以及传输文件

我们一般使用linux的时候，都是在Windows上安装一个ssh客户端连接上去。那么从一台linux如何连接到另一条linux呢？使用ssh命令即可，因为每台linux机器自己都有一个ssh客户端。现在我们使用Python的paramiko模块可以实现ssh客户端，通过Python脚本远程登录一台机器并执行相关操作。
为什么要使用Python来实现ssh客户端呢？主要作用是用来作批量管理。如果让你使用ssh命令登录1台linux机器还好，但是如果让1000台机器同时执行一个命令怎么办呢？当然你可以使用shell脚本写一个for循环来实现，我们使用Python也可以实现。

paramiko模块：基于SSH用于连接远程服务器并执行相关操作

首先安装paramiko模块

基本命令：pip install paramiko

C:\Users\Administrator>pip install paramiko #由于我PC上同时安装了Python2和Python3，所以会报错

Fatal error in launcher: Unable to create process using '"'

C:\Users\Administrator>python3 -m pip install paramiko #用这个命令安装就好啦

...

Successfully installed asn1crypto-0.24. bcrypt-3.1. cffi-1.12. cryptography-

.6.1 paramiko-2.4. pyasn1-0.4. pycparser-2.19 pynacl-1.3. six-1.12.

C:\Users\Administrator>python3 #验证是否安装成功

Python 3.6. (v3.6.5:f59c0932b4, Mar  , ::) [MSC v.  bit (AMD6

)] on win32

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

>>> import paramiko #不报错说明安装成功

>>>

PS：别看上面用命令安装paramiko这么简单，刚开始跟着网上博客离线安装各种报错，浪费了我整整1天的时间，哎，说多了都是泪啊。。。

Win7系统下安装paramiko实操

[root@hadoop ~]# cd /usr/local/python3/bin/

[root@hadoop bin]# pip3 install paramiko #直接安装会报错，所以请按下面步骤安装

pip._vendor.requests.packages.urllib3.exceptions.ReadTimeoutError: HTTPSConnectionPool(host='files.pythonhosted.org', port=): Read timed out.

.安装组件

[root@hadoop ~]# install openssl openssl-devel python-dev   pycrypto -y

[root@hadoop ~]# yum install zlib-devel zlib #必须安装，不安装会报错

[root@hadoop ~]# cd /usr/local/python3/

[root@hadoop python3]# ./configure #安装zlib-devel需要对python3.5进行重新编译安装

[root@hadoop python3]# make & make install

.安装setuptools:

[root@hadoop python3]# cd bin

[root@hadoop bin]# pip3 install setuptools #貌似安装python3.6时已经顺带安装过了

Requirement already satisfied: setuptools in /usr/local/python3/lib/python3./site-packages

.安装paramiko

[root@hadoop bin]# pip3 install paramiko #安装成功未报错

Successfully installed asn1crypto-0.24. bcrypt-3.1. cffi-1.12. cryptography-2.6. paramiko-2.4. pyasn1-0.4. pycparser-2.19 pynacl-1.3. six-1.12.

[root@hadoop bin]# python3 #验证是否安装成功

Python 3.6. (default, Sep  , ::)

[GCC 4.8.  (Red Hat 4.8.-)] on linux

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

>>> import paramiko #不报错说明安装成功

>>>

参考：https://www.cnblogs.com/chimeiwangliang/p/7193187.html

CentOS7系统下安装paramiko实操

SSHClient

用于连接远程服务器并执行基本命令

基于用户名密码连接：

import paramiko

# 创建SSH对象

ssh = paramiko.SSHClient()

# 允许连接不在know_hosts文件中的主机，否则可能报错：paramiko.ssh_exception.SSHException: Server '192.168.43.140' not found in known_hosts

ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())

# 连接服务器

ssh.connect(hostname=b'192.168.43.140', port=22, username=b'root', password=b'123123')

# 执行命令

# stdin：标准输入（就是你输入的命令）；stdout：标准输出（就是命令执行结果）；stderr:标准错误（命令执行过程中如果出错了就把错误打到这里），stdout和stderr仅会输出一个

stdin, stdout, stderr = ssh.exec_command('df')

# 获取命令结果

result = stdout.read().decode() # 这个有问题，不显示错误，可以修改一下，先判断stdout有没有值，如果输出没有，就显示错误

print(result)

# 关闭连接

ssh.close()

#Author:Zheng Na

import paramiko

transport = paramiko.Transport(('192.168.43.140', ))

transport.connect(username='root', password='')

ssh = paramiko.SSHClient()

ssh._transport = transport

stdin, stdout, stderr = ssh.exec_command('df')

result = stdout.read().decode()

print(result)

transport.close()

SSHClient 封装 Transport

基于公钥密钥连接：

import paramiko

# 首先指定你的私钥在哪个位置（ssh是自动找到这个位置，Python不行，必须指定）

private_key = paramiko.RSAKey.from_private_key_file('id_rsa')

# 创建SSH对象

ssh = paramiko.SSHClient()

# 允许连接不在know_hosts文件中的主机

ssh.set_missing_host_key_policy(paramiko.AutoAddPolicy())

# 连接服务器

ssh.connect(hostname='192.168.43.140', port=22, username='root', pkey=private_key)

# 执行命令

stdin, stdout, stderr = ssh.exec_command('df')

# 获取命令结果

result = stdout.read().decode()

print(result)

# 关闭连接

ssh.close()

import paramiko

private_key = paramiko.RSAKey.from_private_key_file('id_rsa')

transport = paramiko.Transport(('192.168.43.140', ))

transport.connect(username='root', pkey=private_key)

ssh = paramiko.SSHClient()

ssh._transport = transport

stdin, stdout, stderr = ssh.exec_command('df')

result = stdout.read().decode()

print(result)

transport.close()

SSHClient 封装 Transport

#Author:Zheng Na

import paramiko

from io import StringIO

key_str = """-----BEGIN RSA PRIVATE KEY-----

MIIEpQIBAAKCAQEA+4kJjKuG2uYNuTZ1SsBr5kCd5GPHV9MU1OsqqXjJlFDvFwa/

/DtPNgeimA6bkHLdd63j0pDpgY/r5jcyH1bLbHMq97hYzNEJZ4GsEDMjnR0qFLTm

QtD2qj+Y6bEmNj39PgGs8sWN+1O4fPWDvGQTnmCytGOTYPA9LtMWkjHcTTNk9UqC

x5kSlhASSuf0DEtBrpKGUDT1G6BYVDQN3rALAZVAtLOEDCZWcKl8bk8OtuIc4WeL

/5JPD0BIquPTcwl7DaALW2isut/RFiqhPWoYgexovQEiHhbuGfJQK9WFUxyOjby

9mS3BdN+1nFg4aWIa+iVH8cUMIJLxO1bJzEdjQIDAQABAoIBAQDEzPdXxGyCoDRk

kSM8FUlWoX/nzdmN8Wz/GfALIKI3FQu77GARrSXQlDC239b/MZ/tn3P8r7zCziQ3

vz/MHVCTzZf0sZtoxLSi82X4VsqqhsMB6HewF2am1ZOCZEQNdHrLJOx4FfF8joht

3Hnx0Cs5Y1bupGoPEmgMVsP2JmTDUMG5ZUCUJigRJ1W38gfx17ZFziaDWPVrMFwy

/zJ8kw5w/ZRn1pw2PeIahSFsGMFVGfm78PXVANr9wOB2YVYuQxOzzHwo8JQnBRke

wYdg1oDHn74HVBNeHUN4YXVwAP8Ggieq/mnHAb36RSIqk6y51KnypR1BiKcSmn+i

VQ6QR7GBAoGBAP81ZcL/pMenSaIQ8nev2evcqXwyJHfDRH1CWPxSygNfcePlEF1I

+OecYswPvlV+iHangnfnt1xZcTTZXQpAyn7xmKk133sOe5f4Jq2vzjqK8mqmWTDw

5OeQIQ3Uuh0XrX93CZpRhgOctL1k6exFSkGkCWnDJOX05+WGrXhoG3IlAoGBAPxQ

uUOJ2k9o1kKylMUYAYpk8y7QwwVSlBhm5Hy1Y6X1Rk2/ERuiebzpSeynXcq+rJyr

tmDaxokzasVcP+YMgDwLF1buENDA2UQzUaZjnPds4M6R89xjWbEJ6q3+jFK8JvSd

KcSJab/fP83tKApmoR0qfXR1yWEe+k5LaBTio/1JAoGAJr4XdbPTcw+9SOIjvPGw

NnMoM5d1G81D73QMCDoVOs/ZfUw/4Ll8N8Tw5qOZNGdiFgk18Df4CQf2/Jvm2PCf

DQhmMYHhLFA1iQt9664ds5t2U6RvM9POHC0wJ2Zc3p/CkfAjQA8SNigq8/mG3Xxj

WnWpjCm4x0QXlCuO2BGN4RUCgYEA0HjOKhyLcVM4vREaVKLaGwP/3e2FRS+Ox360

SMoClIvM084Lj562IT1L5CoBF9RlgGlsHiiFI7WFAZ6P+T7Y8UNkvGGlKSY+Hdid

HPJvLgwazvLO34iDAgEkkzCftnhZY4E7knTLGEqYSEgr7jQP6K5Dy+bKReG3hNtP

GvqL7mkCgYEA+MKBttwVDv8qmOx6UzVhUlVvp8W+/Db1hC0L/bnhx3Fcp0ZpV+dn

3htyqOnP4XYj86PUPFo9Vl3niQKjSuoo4EVchLTIAupndZGw238lX5puqxJJTyxZ

oNrD9RgeiT6GWeLOxnDUsp/hSASix3PRSNTrJGqdOKnwgkBJaLNM6ic=

-----END RSA PRIVATE KEY-----

"""

private_key = paramiko.RSAKey(file_obj=StringIO(key_str))

transport = paramiko.Transport(('192.168.43.140', ))

transport.connect(username='root', pkey=private_key)

ssh = paramiko.SSHClient()

ssh._transport = transport

stdin, stdout, stderr = ssh.exec_command('df')

result = stdout.read().decode()

print(result)

transport.close()

基于私钥字符串进行连接

SFTPClient

用于连接远程服务器并执行上传下载（ssh本身可以使用scp命令传文件，它是基于sftp协议）

基于用户名密码上传下载

import paramiko

transport = paramiko.Transport(('192.168.43.140', 22))

transport.connect(username='root', password='123123')

sftp = paramiko.SFTPClient.from_transport(transport)

# 将location.txt 上传至服务器 /tmp/f_win.txt

sftp.put('location.txt', '/tmp/f_win.txt')

# 将/tmp/test.txt 下载到本地 f_linux.txt

sftp.get('/tmp/test.txt', 'f_linux.txt')

transport.close()

基于公钥密钥上传下载

import paramiko

private_key = paramiko.RSAKey.from_private_key_file('id_rsa')

transport = paramiko.Transport(('192.168.43.140', 22))

transport.connect(username='root', pkey=private_key)

sftp = paramiko.SFTPClient.from_transport(transport)

# 将location.txt 上传至服务器 /tmp/f_win.txt

sftp.put('location.txt', '/tmp/f_win.txt')

# 将/tmp/test.txt 下载到本地 f_linux.txt

sftp.get('/tmp/test.txt', 'f_linux.txt')

transport.close()

#Author:Zheng Na

import paramiko

import uuid

class Haproxy(object):

    def __init__(self):

        self.host = '192.168.43.140'

        self.port =

        self.username = 'root'

        self.pwd = ''

        self.__k = None

    def create_file(self):

        file_name = str(uuid.uuid4())

        with open(file_name,'w') as f:

            f.write('hello paramiko')

        return file_name

    def run(self):

        self.connect()

        self.upload()

        self.rename()

        self.close()

    def connect(self):

        transport = paramiko.Transport((self.host,self.port))

        transport.connect(username=self.username,password=self.pwd)

        self.__transport = transport

    def close(self):

        self.__transport.close()

    def upload(self):

        # 连接，上传

        file_name = self.create_file()

        sftp = paramiko.SFTPClient.from_transport(self.__transport)

        sftp.put(file_name, '/tmp/tttt.txt')

    def rename(self):

        ssh = paramiko.SSHClient()

        ssh._transport = self.__transport

        # 执行命令

        stdin, stdout, stderr = ssh.exec_command('mv /tmp/tttt.txt /tmp/oooo.txt')

        # 获取命令结果

        result = stdout.read().decode()

ha = Haproxy()

ha.run()

Demo

补充：

1.使用ssh的密钥来连接远程服务器的原理：

RSA：非对称加密算法

公钥：public key

私钥：private key

如果你想连接服务器，首先本地生成密钥对，然后本地保存私钥，把公钥拷贝给服务器。

比如：本地（172.16.134.128，私钥）——>远程服务器（172.16.134.129，公钥）

步骤：

本地操作：

[root@hadoop ~]# ssh-keygen #生成密钥对

[root@hadoop ~]# ssh-copy-id root@172.16.134.129  #使用命令将公钥拷贝给远程服务器

[root@hadoop ~]# ssh root@172.16.134.129 #登录远程服务器

本地（172.16.134.128）

[root@hadoop ~]# ssh-keygen  #生成密钥对

Generating public/private rsa key pair.

Enter file in which to save the key (/root/.ssh/id_rsa):   #回车，将私钥保存在/root/.ssh/id_rsa默认文件中

Enter passphrase (empty for no passphrase):   #回车

Enter same passphrase again:   #回车

Your identification has been saved in /root/.ssh/id_rsa. #私钥保存位置

Your public key has been saved in /root/.ssh/id_rsa.pub. #私钥保存位置

The key fingerprint is:

SHA256:Jo4+uE0HO78Hg4+F7Nm//TYx8igi7ddbFk+vkvBH6YI root@hadoop

The key's randomart image is:

+---[RSA ]----+

|                 |

|                 |

|                 |

|                 |

|   ..o. S   . .. |

|    +=+o  o o+o. |

|   o=Boo . Bo*. .|

|  .+*+= +.EoO o. |

|  ..o++*ooo+.=.  |

+----[SHA256]-----+

[root@hadoop ~]# more /root/.ssh/id_rsa #查看私钥，注意私钥不要拷贝给任何人

-----BEGIN RSA PRIVATE KEY-----

MIIEpAIBAAKCAQEAsE9XuFPI0rHnLn6dDprDbAo+L9l5yYthgC2JsYAJTECchq9h

FdynquzRveBy3t0UgidFSHvTmXYsOAZC1svwWATRtq53/fRCU4Gd5FkYCB/2v2Gm

w7FxRl/ExmNJAlHhx5ZQK5qYRJWOlb1hOh+BfGJHX8ns6TuNwmv8hl9HpElgoqw1

5Lc09NZp8eHwcorKOPK0IMchdxPSQYvFvarKdNN0SQ8DhHoa5bZre46urSfnBZmr

N7AOxegpO7mGPkAqCrG2Deia9EcMLl4uHybSb6LhiueG31qOSpBgR1f71rsSMDMu

srL3MSZCtPAXYuN6yxKSQDbZbrr8HqtfrTwb5QIDAQABAoIBAGwcyyKJpfylAKj/

FNnOxwSqJ0X6KncPFAOgaO3CIHF0sUbZpkPcoafrPhYb2vSURq4k3JQ88h0JXMYh

+Lx0I/YlRl+qDoRYUo+YTLSoeVcKGqlyfOtFFLvdn/EzEqLsiPF1V8XVL4fm2Z8y

mLsmdKVMMo4naTH/xcaxpxDSvkCbhJ1f/mWJ93muLZ46IkkyA4WFBoR59IdFHoKO

Y+EFAW8AaYitvyecjFFfNhDsEcK7/Td90LaEI526+L4VGstH7bxvhyKSBl10X4QG

HWG/IhSItLaif6L32HcZ4qVNR+50fEG7gXGWogBi8kCeF9TWsd/8U2kePiP9f6Ld

JNV0TOECgYEA6HlYPDQE02434lSiwxd+TDCkpqlsy9yer4aeuVowQb0VP6l/Pgjj

vjju06hE3IUDc4502VvqGKdhMFMj7biqLFRY24tFok0CbdvIuuQDy81U7Mxp12Wt

eGjl19ibEB0MMoaw5PatcpU1ow2w9ghT6hf/AmbL6VN1dTH2ypxHZ40CgYEAwib3

mIwfgLKVFK/A/HmRDVB7fBnaqZScqGyNxcqMrg9XQmhpr1gOYJy6ziSy6zfvjZSK

zJ68GxfDwqJImYhAG4+R44yMMrvnIRnFKRUg+c522ErjpTxB/JEMfUo0ig8N2wEO

boWZrDz3d7IZaMvTiYw8ZHpesVU5SS6h19DiI7kCgYEA3VJRH5fClGvVRmOfRS8D

rZON3aFlE7ypUqBOUlY7pQpXxXEf07Zw47OeI+GKFYuI2qXgNuMbvnbzvycYCIUL

dgKjSfiQxdCdJGve8ZaMyqVkWcDObyO8/+qWD2WHUtLkvuGeXY0/WdwV4XLya3lI

MpC/1dB6B1vOclGsC/62uC0CgYBEhbA4/KtZpq2LAYShFt6kzlTmtdFArJylrLpU

pmoEPJHVdDholDFu06Hyg21KKxG27EgYc6V8AmUq2k+5MCdAEumwX7hTZ5HpUskM

+NIMmFvFdpjlhmDbnO3Fgl0MpMeFFdhcFXbpHRNSAV+KZvWfxAjEhZPKDoQLWhPw

sV4+sQKBgQCKsUWeNntWr1LdcSsRigMOJ6ZF/QLXiZkmx97UmqLFQIG9+K0s7hHb

qmsucmYZPs46qkAinimSsZ6HksSKRwRmZNEzKQgH/ua3gsjGqbjNkZKxXOCQ9PCF

l6yw27/x2onIVGj5kVGt1yYfPrBspKimPB3O7p7y3igFF/TRMTHn2A==

-----END RSA PRIVATE KEY-----

[root@hadoop ~]# more /root/.ssh/id_rsa.pub #查看公钥

ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCwT1e4U8jSsecufp0OmsNsCj4v2XnJi2GALYmxgAlMQJyGr2EV3Keq7NG94HLe3RSCJ0VIe9OZdiw4BkLWy/BYBNG2rnf99EJTgZ3kWRgIH/a/YabDsXFGX8TGY0kCUeHHllArmphElY6VvWE6H4F8Ykd

fyezpO43Ca/yGX0ekSWCirDXktzT01mnx4fByiso48rQgxyF3E9JBi8W9qsp003RJDwOEehrltmt7jq6tJ+cFmas3sA7F6Ck7uYY+QCoKsbYN6Jr0RwwuXi4fJtJvouGK54bfWo5KkGBHV/vWuxIwMy6ysvcxJkK08Bdi43rLEpJANtluuvweq1+tPBvl r

oot@hadoop

[root@hadoop ~]# ssh-copy-id root@172.16.134.129 #使用命令将公钥拷贝给远程服务器

/usr/bin/ssh-copy-id: INFO: Source of key(s) to be installed: "/root/.ssh/id_rsa.pub"

/usr/bin/ssh-copy-id: INFO: attempting to log in with the new key(s), to filter out any that are already installed

/usr/bin/ssh-copy-id: INFO:  key(s) remain to be installed -- if you are prompted now it is to install the new keys

root@172.16.134.129's password:

Number of key(s) added:

Now try logging into the machine, with:   "ssh 'root@172.16.134.129'"

and check to make sure that only the key(s) you wanted were added.

[root@hadoop ~]# ssh root@172.16.134.129  #成功登录远程服务器

Last login: Fri Mar   ::  from 172.16.134.128

[root@hadoop ~]# ip addr #查看远程服务器IP

: lo: <LOOPBACK,UP,LOWER_UP> mtu  qdisc noqueue state UNKNOWN group default qlen

    link/loopback ::::: brd :::::

    inet 127.0.0.1/ scope host lo

       valid_lft forever preferred_lft forever

    inet6 ::/ scope host

       valid_lft forever preferred_lft forever

: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu  qdisc pfifo_fast state UP group default qlen

    link/ether :0c::bd:: brd ff:ff:ff:ff:ff:ff

    inet 172.16.134.129/ brd 172.16.134.255 scope global noprefixroute dynamic eth0

       valid_lft 1339sec preferred_lft 1339sec

    inet6 fe80::b46e:fbba:4f30:/ scope link noprefixroute

       valid_lft forever preferred_lft forever

[root@hadoop ~]# exit #退出

登出

Connection to 172.16.134.129 closed.

[root@hadoop ~]# 

实操

注意这种连接是单向的，如果希望服务器的用户也可以无密码登录我们本地的用户，则同样需要在服务器的用户下生成密钥对，并把公钥拷贝给我们本地的用户。

除了可以使用命令来将公钥拷贝给服务器外，还可以直接登录远程服务器进行手动拷贝。

.复制存放在/root/.ssh/id_rsa.pub的私钥

.用户登录服务器172.16.134.

.将私钥拷贝到/root/.ssh/authorized_keys文件中。

[root@hadoop ~]# vi /root/.ssh/authorized_keys

注意：

（）公钥在服务器的存放位置由用户来决定。比如我想登录服务器的root用户，就将其拷贝到root文件夹的目标文件中。

（）默认如果你登录过这个用户，则这个用户的.ssh文件会自动生成，如果没登录过这个用户，文件可能需要手动创建。

（）如果你打开authorized_keys文件后看到其中中已经有一个公钥了，那么这应该是别人的，就是说别人如果也想不通过用户名密码登录这台服务器的话，就也会创建密钥对并把公钥放在这里。

（）公钥只有1行，拷贝的时候可能会自动换行变成3行，最终导致登录不成功。可以先把公钥拷到一个txt文件中查看，确定是否只有一行，如果不是，手动删除回车变为一行。更好的办法是用命令拷贝。

.安全起见，查看文件的权限是不是只允许自己读写，如果不是，修改权限。

[root@hadoop ~]# ll /root/.ssh/authorized_keys

-rw-r--r--  root root  Mar   : /root/.ssh/authorized_keys

[root@hadoop ~]# chmod  /root/.ssh/authorized_keys

[root@hadoop ~]# ll /root/.ssh/authorized_keys

-rw-------  root root  Mar   : /root/.ssh/authorized_keys

手动拷贝公钥

本地尝试登录远程服务器时，

若登录不成功，可以使用调试模式查看，-v

[root@hadoop ~]# ssh root@172.16.134.129 -v

若端口不是22，则需要加上端口号，比如

[root@hadoop ~]# ssh root@172.16.134.129 -p52113

登录服务器失败怎么办？

2.为什么要使用公钥连接？

基于用户名密码来连接远程服务器，这是不安全的，一旦被别人拿到你的脚本，获取到用户名密码，别人也就可以连接你的服务器。

3.写Python脚本时，注意不要将名称写为paramiko.py，因为这与模块名重复，执行时会有问题。

4.安装好paramiko模块后第一次运行，可能会出现警告：CryptographyDeprecationWarning

D:\software\Python3.6.5\python3.exe D:/python-study/s14/Day09/paramiko_ssh_pwdlogin.py

D:\software\Python3.6.5\lib\site-packages\paramiko\kex_ecdh_nist.py:: CryptographyDeprecationWarning: encode_point has been deprecated on EllipticCurvePublicNumbers and will be removed in a future version. Please use EllipticCurvePublicKey.public_bytes to obtain both compressed and uncompressed point encoding.

  m.add_string(self.Q_C.public_numbers().encode_point())

D:\software\Python3.6.5\lib\site-packages\paramiko\kex_ecdh_nist.py:: CryptographyDeprecationWarning: Support for unsafe construction of public numbers from encoded data will be removed in a future version. Please use EllipticCurvePublicKey.from_encoded_point

  self.curve, Q_S_bytes

D:\software\Python3.6.5\lib\site-packages\paramiko\kex_ecdh_nist.py:: CryptographyDeprecationWarning: encode_point has been deprecated on EllipticCurvePublicNumbers and will be removed in a future version. Please use EllipticCurvePublicKey.public_bytes to obtain both compressed and uncompressed point encoding.

  hm.add_string(self.Q_C.public_numbers().encode_point())

警告信息

C:\Users\Administrator>python3 -m pip uninstall cryptography==2.5

C:\Users\Administrator>python3 -m pip install cryptography==2.4.

参考：https://yq.aliyun.com/articles/690717

解决方法

5.若希望使用公钥从本地win7系统登录到远程linux服务器，该如何在win7本地生成密钥对呢？

方法一：可以直接从一台linux系统拷贝其私钥到本地（注意：此系统必须已将公钥给过你的服务器）

[root@hadoop ~]# sz ~/.ssh/id_rsa #sz命令可以将文件下载到本地

方法二：可以通过打开XShell-->工具-->新建用户密钥生成向导-->...-->...步骤实现

6.假如Linux下光标消失，不要急：

echo -e "\033[?25l"   #隐藏光标

echo -e "\033[?25h"   #显示光标