Removes single line from known_hosts file

rhost() { if [[ $1 =~ ^[0-9]+$ ]]; then sed -i "$1"d ${HOME}/.ssh/known_hosts; else echo "rhost [n]"; fi }
Quickly remove the conflicting line (key) from current users known_hosts file when there is an SSH host conflict. Very nice when you get tired of writing out full commands. Ideally you would place this into your .bash_profile Usage: rhost [n] Example: rhost 33 (removes line 33 from ~/.ssh/known_hosts) Function assumes the $HOME exists, you could alternatively use "~/.ssh/known_hosts" Mac OSX likes a space for sed -i "$1" d

-1
By: lowjax
2013-08-01 21:10:34

These Might Interest You

  • Easily removes line #2 in ~/.ssh/known_hosts. Show Sample Output


    -1
    perl -p -i -e 's/.*\n//g if $.==2' ~/.ssh/known_hosts
    meappy · 2012-01-17 14:11:03 0
  • sometimes you got conflicts using SSH (host changing ip, ip now belongs to a different machine) and you need to edit the file and remove the offending line from known_hosts. this does it much easier. Show Sample Output


    -1
    function sshdel { perl -i -n -e "print unless (\$. == $1)" ~/.ssh/known_hosts; }
    xsawyerx · 2009-02-03 16:20:50 1
  • deletes line 3 in known_hosts text file


    8
    sed -i 3d ~/.ssh/known_hosts
    evandrix · 2011-05-26 11:34:03 1
  • When you SSH to a server who's hostname or IP has changed since the last time a connection was recorded in the known_hosts file a warning will be displayed since this indicated a possible DNS spoofing attack. If this is a known change then this command will remove the previous entry and allow the SSH connection. The SSH client will prompt you as if it was the first time connected to the server. Replace ${LINE} with the line of the offending key in ~known_hosts. 49 in the sample output. Show Sample Output


    -5
    sed '${LINE}d' ~/.ssh/known_host
    lucasrangit · 2012-01-16 18:00:12 3

What Others Think

You have a much simpler command to clean up the know_hosts file: ssh-keygen -R hostname
jld · 250 weeks and 5 days ago
I cant stand "ssh-keygen -R hostname". IMO. When you are denied access because of conflicting keys, you don't necessarily have the IP/Host available cleanly. You either have the previous SSH command to pull the IP/Host, or go back to what you referenced earlier. Takes time, click, keys, effort. Instead this command allows you to input the line number of the offending key, the one useful tidbit from the denied SSH attempt. Example: ssh me@hostname Outputs : blah blah blah failed, offending key on line 12 rhost 12 ssh me@hostname
lowjax · 250 weeks and 2 days ago

What do you think?

Any thoughts on this command? Does it work on your machine? Can you do the same thing with only 14 characters?

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