Using sed to set PermitRootLogin on OSX

Question

I'm trying to figure out how to enable PermitRootLogin with OSX sed.

I know about the OSX sed issue where you have to give an empty string at the start.

I just need the regex I actually need to do:

if #PermitRootLogin yes or #PermitRootLogin no then replace with PermitRootLogin yes

I've got:

sudo sed -i '' 's/#PermitRootLogin no/PermitRootLogin yes/g' /etc/sshd_config

But this doesn't include if ##PermitRootLogin yes

doubled string replace indicator `s/s/`? – Marc Bredt Jan 21 '15 at 18:16 — Marc Bredt, Jan 21 '15 at 18:16

Barmar · Accepted Answer · 2017-04-27T15:27:57.313

4

The version of sed in OS X requires a parameter after -i for the backup file suffix.

If you don't want a backup file, you have to provide an explicit empty string:

sed -i '' 's/^#?PermitRootLogin \(no\|yes\)/PermitRootLogin yes/' /etc/sshd_config

Without this argument, it's taking the s/.../.../ command as the suffix, and /etc/sshd_config as sed editing command.

Note that some time between Snow Leopard and El Capitan, the location of this SSH configuration file moved from /etc/sshd_config to /etc/ssh/ssh_config.

edited Apr 27 '17 at 15:27

answered Jan 21 '15 at 18:18

Barmar

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Ok, this is making the sed work properly, but the regex isn't working still... – Peter Souter Jan 21 '15 at 20:30
There was an extra `s/` at the beginning of the command. Also, `|` needs to be esaped in `sed` to form alternatives. – Barmar Jan 21 '15 at 20:43
seems to be `/etc/ssh/sshd_config`, at least on 10.12 – Charlie Gorichanaz Apr 27 '17 at 05:07
1

@CharlieGorichanaz In El Capitan as well. I've updated the answer to note this. – Barmar Apr 27 '17 at 15:28

Using sed to set PermitRootLogin on OSX

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