expand ssh hostname in shell script

Question

I have a couple of hosts configured in ~/.ssh/config, for example:

Host SomeHost
  Hostname 10.0.0.3
  User SomeUser

I'm trying to get the hostname part (10.0.0.3) as a variable from inside a shell script (the %h variable). Is it somehow possible?

Short of parsing the file yourself, no. The configuration doesn't exist outside of the file until ssh reads it when executed, and ssh doesn't provide an API for querying configurations. — chepner
– chepner, Commented Aug 31, 2014 at 14:53
This sounds like an XY problem -- what problem are you're really trying to solve? — glenn jackman
– glenn jackman, Commented Aug 31, 2014 at 15:32
@glennjackman I'm trying to use nmap to see if the remote host has port 22 open. It is much faster than using ssh to use a test connection. — Devon Ville
– Devon Ville, Commented Sep 1, 2014 at 8:29

glenn jackman · Accepted Answer · 2014-09-01 14:17:09Z

1

host2ip() {
    awk -v host="$1" '
        $1 == "Host" && $2 == host {have_host = 1}
        have_host && $1 == "Hostname" {print $2; exit}
    ' ~/.ssh/config
}

ip=$(host2ip SomeHost)
echo $ip

10.0.0.3

answered Sep 1, 2014 at 14:17

glenn jackman

249k42 gold badges233 silver badges363 bronze badges

Sign up to request clarification or add additional context in comments.

Collectives™ on Stack Overflow

expand ssh hostname in shell script

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related