What is the best method for adding and removing entries to/from the /etc/hosts file?

Question

When I'm on a work VPN I need to access a particular internal site but I need to tunnel through SSH through one of our dev servers to get to it. This is fine.

However whenever I need to do this, I need to add an entry to the hosts file to alias this particular domain to localhost and do the SSH tunnelling, and consequently when I've finished I need to remove the entry from the hosts file. I thought I'd automate this which is relatively easy. However managing the hosts file is not as easy as I thought:

I've tried:

cat /etc/hosts | grep -v 'internal.name.company.com' > /etc/hosts

However this always results in an empty /etc/hosts file. If I run cat /etc/hosts | grep -v 'internal.name.company.com' I get the output I want exactly. Am I missing something obvious? When I redirect the output to another file, say ~/test the result is as expected and this file contains the contents I expect.

Yes this is a duplicate, my bad I didn't think of searching for that as the problem :(. Voted to close as duplicate. — Sam Giles, Sep 11 '13 at 14:48
If you just have answers with 0 score, you can still delete it! — fedorqui, Sep 11 '13 at 14:49

score 4 · Answer 1 · edited Sep 11 '13 at 15:01

4

Try this way:

grep -v 'internal.name.company.com' /etc/hosts > /tmp/hosts.tmp ; cp /tmp/hosts.tmp /etc/hosts

edited Sep 11 '13 at 15:01

Kamil Budziewski

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answered Sep 11 '13 at 14:45

Valeriy

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score 0 · Answer 2 · answered Sep 11 '13 at 15:17

0

You can also use sed to modify the file directly:

sed '/internal\.name\.company\.com/d' hosts

answered Sep 11 '13 at 15:17

konsolebox

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What is the best method for adding and removing entries to/from the /etc/hosts file?

2 Answers2