使用scp在linux主机之间无密码复制文件/目录

当两台LINUX主机之间要互传文件时可使用SCP命令来实现，建立信任关系之后可不输入密码。

把你的本地主机用户的ssh公匙文件复制到远程主机用户的~/.ssh/authorized_keys文件中
假设本地主机linux100,远程主机linux200
一，在linux100主机里的用户
运行
#ssh-keygen -t rsa
结果如下

QUOTE:
Generating public/private rsa key pair.
Enter file in which to save the key (/home/.username/ssh/id_rsa):#回车
Enter passphrase (empty for no passphrase):#回车
Enter same passphrase again:#回车
Your identification has been saved in /home/.username /.ssh/id_rsa.
Your public key has been saved in /home/.username /.ssh/id_rsa.pub.
The key fingerprint is:
38:25:c1:4d:5d:d3:89:bb:46:67:bf:52:af:c3:17:0c username@localhost
Generating RSA keys:
Key generation complete.

会在用户目录~/.ssh/产生两个文件，id_rsa，id_rsa.pub
二，把linux100主机上的id_rsa.pub文件拷贝到linux200主机的root用户主目录下的.ssh目录下,并且改名为authorized_keys
即：
/root/.ssh/authorized_keys
这样在linux100主机上使用scp命令复制文件到linux200上将不提示输入密码了，直接复制了。
反之亦然！

三，复制文件或目录命令：
复制文件：
（1）将本地文件拷贝到远程
scp 文件名 --用户名@计算机IP或者计算机名称:远程路径
（2）从远程将文件拷回本地
scp --用户名@计算机IP或者计算机名称:文件名 本地路径
复制目录：
（1）将本地目录拷贝到远程
scp -r 目录名 用户名@计算机IP或者计算机名称:远程路径
（2）从远程将目录拷回本地
scp -r 用户名@计算机IP或者计算机名称:目录名本地路径
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把你的本地主机用户的ssh公匙文件写入到远程主机用户的~/.ssh/authorized_keys文件中,具体方法
假设本地主机localhost,远程主机remote

一，在localhost主机里的用户

运行 ssh-keygen -t rsa
结果如下
Generating public/private rsa key pair.

Enter file in which to save the key (/home/.username/ssh/id_rsa):#回车

Enter passphrase (empty for no passphrase):#回车

Enter same passphrase again:#回车

Your identification has been saved in /home/.username /.ssh/id_rsa.

Your public key has been saved in /home/.username /.ssh/id_rsa.pub.

The key fingerprint is:

38:25:c1:4d:5d:d3:89:bb:46:67:bf:52:af:c3:17:0c username@localhost

Generating RSA keys:

Key generation complete.
会在用户目录~/.ssh/产生两个文件，id_rsa，id_rsa.pub

二，把id_rsa.pub文件拷贝到remote主机的用户目录下

cat id_rsa.pub >~/.ssh/authorized_keys
就可以了

这样localhost主机的用户就可以通过ssh而不用密码登陆remote主机

在测试当中发现经常出现以下错误：
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
@ WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED! @
@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
Someone could be eavesdropping on you right now (man-in-the-middle attack)!
It is also possible that the RSA host key has just been changed.
The fingerprint for the RSA key sent by the remote host is
1f:a3:2b:b5:27:0c:5c:7b:89:27:ff:ab:cd:ba:31:66.
Please contact your system administrator.
Add correct host key in /root/.ssh/known_hosts to get rid of this message.
Offending key in /root/.ssh/known_hosts:6
RSA host key for 60.28.15.234 has changed and you have requested strict checking.
Host key verification failed.

解决办法是把known_hosts文件删掉就可以了

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