Change server name in OpenVPN file with sed

Question

I have the following file:

    proto udp
    resolv-retry infinite
    nobind

    #Single line of those bellow, I've added multiple for variations of it 
    remote fi.server.com 50505
    remote us-cityone.server.com 5050
    remote uk-citytwo.server.com 50500
    remote us-citythree.server.com  56546
    remote sweden.server.com 6546546
    rest of config file..

Let me be more clear, this is a OpenVPN conf file. I want to replace only that line that starts with remote servername 5555 - server name a different one.

I've added multiple remote servername 5555 lines just for an example, because they all represent variations that I might occur.

I want to match middle column only, fi.server.com , us-newyorkcity.server.com etc and replace it using sed with different name.

Why pattern like this, doesn't work?

sed -i.bak 's/\w+(-|\.)\.?\w+\.?\.com/g' filename

I've tried this one as well..

sed -i.bak 's/\w+(-|\.)\.?\w+\.?\.\w+/g' filename

Further note, from the example us-newyorkcity.server.com only server.com part is a static one. Rest is changed.

Thanks for help!

Answer 1

Assuming a variable NEWNAME with the name you want to insert, you should be able to use the following:

sed -i.bak "s|^\(remote \)\([^ ]*\)\([ ]*[0-9]*\)|\1$NEWNAME\3|" filename