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Due to my laziness, I have written an extremely "messy" series of scripts in order to auto-initiate my openvpn. The configuration file I am using comes vpnbook.com/freevpn.

To get the password I use:

lynx --dump --nolist vpnbook.com/freevpn | grep -i password | sort -u | cut -b 18,19,20,21,22,23,24

The password is returned from the website.

Then, I use an expect script to automatically login (the user name is always vpnbook, but the password changes depending on the week):

#!/usr/bin/expect -f
spawn openvpn /vpn/vpnbook-ca1-tcp80.ovpn ### my vpn configuration file ###
expect "*?sername:*"
send -- "vpnbook\r"
expect "*?assword:*"
### This next line sends the password that changes by the week, which I...
###...unfortunately need to update manually (for lack of a better method):
send -- "weekly-password\r" 

The problems I am running into when attempting to automatically update the password:

1) I can't call lynx directly from the expect environment.

2) Since the password changes, I am not certain how to replace the the unique pass-phrase from the previous week with the updated version in :

send -- "unique-previous-password\r" 

3) I am not certain how use the string output from the lynx function as an input variable for editing the password from the previous week (located in my expect script).

Quite clearly, I am not "the brightest" programmer (nor am I the most efficient). However, at the end of the day, my only goal is to fully initialize my vpn by typing a single command (as I mentioned before, I am lazy).

Any help would be appreciated, thanks!

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In your expect/tcl script, you can use:

send "$env(PASSWORD)\r"

And call your expect script with with:

PASSWORD=$(elinks -dump...) /path/to/your/expect/script

Note that you can use cut -b18-24 for short.

  • Thank you for your time -- This was a fantastic (not to mention simple) solution to my problem. – AQuestion Jun 14 '17 at 22:05
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Stéphane's solution is very elegant, but in case you don't want to download and parse the password every time, you can retain your two step process with something like this:

Modify your password retrieval command to this:

sed -e '$ d' -i .bak f && echo -n "send -- \"" >> f && lynx --dump --nolist vpnbook.com/freevpn | grep -i password | sort -u | cut -b 18-24 >> f && echo "\\r\"" >> f

For brevity, I've called your expect script file f. In reality it needs to be the complete /path/to/your/expect/script unless you're already in the same directory as the script.

Then call your expect script as usual.

Broken down, the extended command works like this:

  • sed -e '$ d' -i .bak f Find the last line ($) in f and delete it (d). Careful of the -e and -i switches - they are different/not supported on some platforms. -e explicitly specifies the command when the -i switch is in use, and -i means to modify the file in-place, saving a backup with the .bak extension.

  • && execute the next command if the previous one succeeds.

  • echo -n "send -- \"" >> f Append to the file (>> f) without a newline (-n) the first part of the send expect function.

  • lynx... Your original command, except the result is appended to the file (>> f).

  • echo "\\r\"" >> f Append the last part of the send expect function.

  • I would enthusiastically "up-vote" your answer [ if only I had more than 15 reputation]. The thought processes / techniques presented your solution are extremely useful (not to mention, highly applicable to a variety of "slightly different" problems), and I am grateful for the opportunity to add them to my "repertoire." Thank you very much for your time and expertise. – AQuestion Jun 14 '17 at 22:34

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