C++环境下的expect远程命令执行

首先，必须安装几个开发包，在centos/fedora下，可以使用yum安装:

$ yum -y install tcl-devel expect-devel

 

装完以后，就可以使用expect来写代码了，从网上拉下来一段代码，稍微修改了一下:

#include <tcl.h>
#include <expect.h>
#include <stdio.h>
#include <unistd.h>
#include <iostream>
#include <expect_tcl.h>

using namespace std;

int main()
{
	extern int exp_timeout;
	exp_timeout = 100;
	Tcl_Interp *tcl;
	tcl = Tcl_CreateInterp();
	if (Expect_Init(tcl) != TCL_OK)
	{
		puts("failure");
		return 1;
	}
	//start a connection with remote ssh server
	int fd = exp_spawnl("ssh", "ssh", "-p 22", "username@server_address", "echo start;ls ~;", (char *)0);
	if(fd < 0)
	{
		cout<<"Fail to ssh"<<endl;
		return -1;
	}
	int loop = 1;
	int result;
	while(loop)
	{
		//predefine some expected responses
		result = exp_expectl(fd, exp_glob, "*assword: ", 1, exp_exact, "Permission denied, please try again.", 2, exp_regexp, "(The authenticity of host)(.)*(Are you sure you want to continue connecting (yes/no)?)", 3, exp_end);
		char pas[] = "your_password\n";
		switch(result)
		{
			case 1:
				write(fd, pas, sizeof(pas) - 1);
				break;
			case 2:
				cout <<"wrong password"<<endl;
				break;
			case 3:
				cout<<"connect security"<<endl;
				write(fd, "yes\n", 4);
				break;
			case EXP_EOF:
				cout << "EOF\n";
				loop = 0;
				break;
			case EXP_TIMEOUT:
				cout<<"Time out\n";
				loop = 0;
				break;
			default:
				cout<<"logged in "<<result<<endl;
				loop = 0;
				break;
		}
	}
	Tcl_DeleteInterp(tcl);
}

 

 

保存为test-expect.cpp, 编译:

g++ test-expect.cpp -o test-expect -lexpect5.43 -ltcl8.4

 

执行./test-expect，得到远程root用户的根目录列表。 

远程命令的标准输出存在exp_buffer缓冲区。

 

详细的手册可以参考http://www.cims.nyu.edu/cgi-systems/man.cgi?section=3&topic=libexpect