Today, i was trying to VPN to my office network from home, using my ArchLinux (3.12), i installed pptpclient, a vpn tunneling software to achieve that, and followed the instructions mentioned here.I did followed and it warned properly that password with '$' sign be quoted. Ok, to setup vpnclient you do something as follows
pptpsetup --create my_tunnel --server vpn.example.com --username alice --password "$0123abcd" --encrypt
I enclosed my password within " but still my connection could not be successful. I kind of figured out that the issue is with the password and went on along the sides of investigating it. The first thing i did was to see how the password is actually stored, and inspected the file /etc/ppp/chap-secrets. For my surprise i found that the password is stored as zsh123abcd. Then i realized that $0 in the password is evaulated to the current shell i.e zsh and the value stored inside the file for the password is wrong. I edited this file, and things seemed to work great after that.
Have a good time :)