linux 用 SSH2协议远程连接并控制 linux

[参考链接](http://php.net/manual/zh/ssh2.installation.php)

ssh2_exec 并不能打印所有的命令的提示信息

如果有返回的字符串信息，可以打印，或重定向输出查看；
如果只有提示性的信息，则无论如何是看不到的

yum list installed | grep libssh2
sudo yum install -y libssh2

yum list installed | grep libssh2-devel.x86_64

CentOS 6.2 64bit Installation Steps:

1. download the libssh2 package from http://libssh2.org, command as following:
    
    * can install by yum
            
            tar vxzf libssh2-1.4.2.tar.gz
            cd libssh2-1.4.2
            ./configure
            make
            make install

2. download the php-ssh2 package from http://pecl.php.net/package/ssh2:

sudo yum install -y php-devel

tar vxzf ssh2-0.12.tgz
cd ssh2-0.11.3
phpize
./configure --with-ssh2
make
sudo make install

and the ssh2.so file will copy into /usr/lib64/php/modules
check it.

3. modify the php.ini

vi /etc/php.ini

add the "extension=ssh2.so" to the extension part of php.ini

4. check the environment of php, use phpinfo();

5. enjoy