Re: Sed or awk: remove a line from a file

[fra-du@tourde.org (François TOURDE)]

Le 14757ième jour après Epoch,
Dotan Cohen écrivait:

> As I regularly format my test box, I often get stuck SSHing into it, like this:
>
> $ ssh user@domain
> @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
> @    WARNING: REMOTE HOST IDENTIFICATION HAS CHANGED!     @
> @@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@
> IT IS POSSIBLE THAT SOMEONE IS DOING SOMETHING NASTY!
> Someone could be eavesdropping on you right now (man-in-the-middle attack)!
> It is also possible that the RSA host key has just been changed.
> The fingerprint for the RSA key sent by the remote host is
> --:--:--:--:--:--:--:--:--:--:--:--:--:--:--:--:--:--:--:--
> Please contact your system administrator.
> Add correct host key in /home/user/.ssh/known_hosts to get rid of this message.
> Offending key in /home/user/.ssh/known_hosts:44
> RSA host key for domain has changed and you have requested strict checking.
> Host key verification failed.
>
>
>
> Now, I need strict checking but I'd like to just remove line 44 from
> ~/.ssh/known_hosts. Easy to do in VIM, probably even easier to do in
> sed or awk. But I've been reading sed and awk tutorials for two hours
> and I cannot figure out how to remove line N from the file without
> creating a second file. If I'm already going through the hassle of
> creating then moving a second file then I might as well just edit the
> file in VIM.
>
> Any ideas?

Don't use sed nor awk...

man ssh-keygen say:

     -R hostname
             Removes all keys belonging to hostname from a known_hosts file.  This option is useful to delete hashed
             hosts (see the -H option above).