如何使用Expect替换远程主机上的IP地址

Question

I write the following expect script in order to replace the IP address on remote linux machine

I use the perl one linear for this task

I get errors about can't read "HOME": no such variable ,

please advice what I need to change in my expect script so I will change the requested IP ?

 #!/bin/ksh


 expect_transfer=`cat << EOF
 set timeout -1
 spawn  ssh  12.219.102.43
       expect {
                 ")?"   { send "yes\r"  ; exp_continue  }

                 word:  {send pass123\r}
              }
  expect #  {send "export OLD=10.10.10.10 ; export NEW=1.1.1.1 ; perl -i -pe 's/\Q$ENV{OLD}\E/$1$ENV{NEW}$2/' /etc/hosts\r"}
  expect #    {send exit\r}
  expect eof
  EOF`


  expect -c  "$expect_transfer" 

results:

  spawn ssh 12.219.102.43
  root@12.219.102.43's password: 
  Last login: Sun Aug  4 12:29:25 2013 from 12.219.102.43
  [root@localhost ~]# can't read "HOME": no such variable
  while executing
   "send "export OLD=10.10.10.10 ; export NEW=1.1.1.1 ; perl -i -pe 's/\Q$HOME/.kshrc{OLD}\E/$HOME/.kshrc{NEW}/' /etc/hosts\r""
  invoked from within
  "expect #  {send "export OLD=10.10.10.10 ; export NEW=1.1.1.1 ; perl -i -pe 's/\Q$HOME/.kshrc{OLD}\E/$HOME/.kshrc{NEW}/' /etc/hosts"

• I will happy to get any other solution under ksh scripts

Answer 1

Quote the “EOF” (here document marker) in the line where you use it, that is, change

expect_transfer=`cat << EOF

into

expect_transfer=`cat << \EOF

or

expect_transfer=`cat << 'EOF'

When you do not quote the here document marker, the shell interpolates variable references like $ENV inside the here document. In your case, ENV='$HOME/.kshrc' so that Perl does not see $ENV{OLD} but $HOME/.kshrc{OLD} which is clearly wrong.