Pexpect未按预期工作。它不会在虚拟机上返回正确的输出

Question

[注意：我在物理机器上运行了这个代码，它可以工作（OS=fedora14）。但是当我在虚拟机上安装的Ubuntu中使用相同的脚本时，它不起作用。我正在尝试捕获ifconfig输出并保存/打印它。]

我已经在VMPlayer上安装了Ubuntu（它是虚拟机）。我正在使用python脚本语言，并尝试使用Pexpect自动化SSH连接。我在同一个Ubuntu虚拟机上运行这个脚本。下面是我用这个脚本做的事情：

1. 使用Pexpect，通过SSH连接到本地主机
2. 执行“ifconfig”cli命令并捕获输出。在
3. 打印此cli输出。在

代码段：

  class Linux:
    HOSTIP      =    ""
    USER        =    ""
    PASSWD      =    ""
    HOST        =    ""

    PROMPTTIMEOUT =    120
    PROMPT        =    ""
    ERRORFLAG     =    False
    ERRORMSG      =    ""
    CLIOUTPUT     =    ""


    def __init__(self,host, user, passwd, prompt):
        self.HOSTIP    =    host
        self.USER      =    user
        self.PASSWD    =    passwd
        self.PROMPT    =    prompt
        self.login()

    def login(self):
        try:
            connection   =    "ssh " + self.USER + "@" + self.HOSTIP
            self.HOST    =    pexpect.spawn(connection)
            while 1:
                returnNum    =    self.HOST.expect(["yes/no","password:"],120)
                if returnNum == 0:
                    self.HOST.send("yes\r\n")        
                elif returnNum == 1:
                    self.HOST.send(self.PASSWD + "\r\n")
                    break
            self.HOST.expect(self.PROMPT,120)
            self.CLIOUTPUT  =       self.HOST.before                        
            self.HOST.send("\r\n")
            self.HOST.expect(self.PROMPT,120)
            self.CLIOUTPUT  =       self.CLIOUTPUT + self.HOST.before
        except Exception:
            return False
        return True


    def executeCLI(self, cmd):
        self.resetErrors()
        try:
            self.HOST.send("\r\n")
            self.HOST.expect(self.PROMPT,120)
            self.HOST.send(cmd + "\r\n")
            self.HOST.expect(self.PROMPT,120)

            self.CLIOUTPUT     =    self.HOST.before
            self.HOST.send("\r\n")
            self.HOST.expect(self.PROMPT,120)

            self.CLIOUTPUT    =    self.CLIOUTPUT + self.HOST.before
        except Exception:
            return False
            return True

    def getCLIOutput(self):
            return self.CLIOUTPUT

# Testing Class Linux.py                        

host    =    Linux("1.1.1.1", "admin", "admin123", "@ubuntu")
host.executeCLI("ifconfig")
print("Output : " + str(host.getCLIOutput()))

结果输出：

^{pr2}$

预期产量：

admin@ubuntu12:/home/Host# ifconfig
eth0      Link encap:Ethernet  HWaddr 00:0c:29:60:6b:be
          inet addr:192.168.2.5  Bcast:192.168.2.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe60:6bbe/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:1733 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1539 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:205502 (205.5 KB)  TX bytes:252126 (252.1 KB)
          Interrupt:19 Base address:0x2024

eth1      Link encap:Ethernet  HWaddr 00:0c:29:60:6b:c8
          inet addr:20.20.20.2  Bcast:20.20.20.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe60:6bc8/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:49 errors:0 dropped:0 overruns:0 frame:0
          TX packets:82 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:5132 (5.1 KB)  TX bytes:12322 (12.3 KB)
          Interrupt:16 Base address:0x20a4

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:170 errors:0 dropped:0 overruns:0 frame:0
          TX packets:170 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:27353 (27.3 KB)  TX bytes:27353 (27.3 KB)

admin@ubuntu12:/home/Host#

如果我手动将SSH登录到本地主机并在CLI上执行IFCONFIG命令，那么我将在屏幕上看到以下输出：

admin@ubuntu12:/home/Host# ssh admin@192.168.2.5
admin@192.168.2.5's password:
Welcome to Ubuntu 12.04.3 LTS (GNU/Linux 3.2.0-29-generic-pae i686)

 * Documentation:  https://help.ubuntu.com/

67 packages can be updated.
35 updates are security updates.

Last login: Sat Sep 21 22:55:36 2013 from 192.168.2.5
admin@ubuntu12:~$ ifconfig
eth0      Link encap:Ethernet  HWaddr 00:0c:29:60:6b:be
          inet addr:192.168.2.5  Bcast:192.168.2.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe60:6bbe/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:4270 errors:0 dropped:0 overruns:0 frame:0
          TX packets:3664 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:463331 (463.3 KB)  TX bytes:625129 (625.1 KB)
          Interrupt:19 Base address:0x2024

eth1      Link encap:Ethernet  HWaddr 00:0c:29:60:6b:c8
          inet addr:20.20.20.2  Bcast:20.20.20.255  Mask:255.255.255.0
          inet6 addr: fe80::20c:29ff:fe60:6bc8/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:153 errors:0 dropped:0 overruns:0 frame:0
          TX packets:105 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000
          RX bytes:15340 (15.3 KB)  TX bytes:14388 (14.3 KB)
          Interrupt:16 Base address:0x20a4

lo        Link encap:Local Loopback
          inet addr:127.0.0.1  Mask:255.0.0.0
          inet6 addr: ::1/128 Scope:Host
          UP LOOPBACK RUNNING  MTU:16436  Metric:1
          RX packets:1456 errors:0 dropped:0 overruns:0 frame:0
          TX packets:1456 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0
          RX bytes:192908 (192.9 KB)  TX bytes:192908 (192.9 KB)

admin@ubuntu12:~$

Answer 1

将所有“\r\n”替换为“\n”，这样就可以工作了