Remove a line from a file using sed (useful for updating known SSH server keys when they change)

sed -i '${LINE}d' ~/.ssh/known_host

By: richard

2012-01-19 11:22:45

sed

4 Alternatives + Submit Alt

Remove a line from a file using sed (useful for updating known SSH server keys when they change)

remove the host for the .ssh/know_host file
This is sample output - yours may be different.
16

ssh-keygen -R <thehost>

bunam · 2012-01-16 21:07:44 15
Remove a line from a file using sed (useful for updating known SSH server keys when they change)

For example, to remove line 5 from foo, type: vi +5d +wq foo
This is sample output - yours may be different.
1

vi +<lineNumber>d +wq <filename>

detert · 2012-01-25 18:28:03 5
Remove a line from a file using sed (useful for updating known SSH server keys when they change)

Easily removes line #2 in ~/.ssh/known_hosts. Show Sample Output
This is sample output - yours may be different.
-1

perl -p -i -e 's/.*\n//g if $.==2' ~/.ssh/known_hosts

meappy · 2012-01-17 14:11:03 4

Remove a line from a file using sed (useful for updating known SSH server keys when they change)

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 -i '${LINE}d' ~/.ssh/known_host

lucasrangit · 2012-01-16 18:00:12 7

What Others Think

Probably you want '~/.ssh/known_hosts' (mind the final 's').

funollet · 664 weeks and 1 day ago

This command isn't portable across unices, has a typo, and requires you to know the line before running this command. Using ssh-keygen(1) is the preferred, portable way.

atoponce · 664 weeks and 1 day ago

Portable is relative. I have an old Redhat system here that doesn't even know the -i switch to sed ;)

assarbad · 658 weeks and 1 day ago

rahimhh21 · 111 weeks ago

Perfecthomepugs · 101 weeks and 4 days ago

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wandasuwari · 38 weeks and 3 days ago

yeneba6574 · 17 weeks and 1 day 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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