Printing alias from ~/.ssh/config— with or without trailing hyphen

Question

I have following file, it's a config file for ssh.

Host vps2 # Linode
    HostName xxx.xx.xx.xxx
    User foo_user

Host vps3 # Vultr
    HostName xxx.xx.xx.xxx
    User foo_user   

Host vps4
    HostName xxx.xx.xx.xxx
    User foo_user

Host vps5
    HostName xxx.xx.xx.xxx
    User foo_user 

Host vps6
    HostName xxx.xx.xx.xxx
    User foo_user 

Host vps7 # DigitalOcean
    HostName xxx.xx.xx.xxx
    User foo_user

Host vps8 # GCP
    HostName xxx.xx.xx.xxx
    User foo_user   

Host pi
   HostName xxx.xx.xx.xxx
   User pi

# OLD SHALL NOT BE USED

Host vps13
    HostName xxx.xx.xx.xxx
    User foo_user

Host vps14-old
   HostName xxx.xx.xx.xxx
   User foo_user 

Host vps4-old
    HostName xxx.xx.xx.xxx
    User foo_user 

Host vps15-old
   HostName xxx.xx.xx.xxx
   User foo_user 

Host vps11-old
    HostName xxx.xx.xx.xxx
    User foo_user

I need to print alias that start with vps*, below (copied) snippets will exactly do that.

$ awk '{for(i=1;i<=NF;i++){if($i~/^vps/){print $i}}}' $HOME/.ssh/config
vps2
vps3
vps4
vps5
vps6
vps7
vps8
vps3-old
vps4-old
vps5-old
vps11-old

Now I want to print all alias that has no -old suffix, adding | grep -v old works.

$ awk '{for(i=1;i<=NF;i++){if($i~/^vps/){print $i}}}' $HOME/.ssh/config | grep -v "old"
vps2
vps3
vps4
vps5
vps6
vps7
vps8

Is there any cleaner way ? Preferably involving only 1 tools, I tried playing with awk command to no avail.

Answer 1

You could add a $i!~/-old$/ condition to the awk command:

awk '{for(i=1;i<=NF;i++){if($i~/^vps/ && $i!~/-old$/){print $i}}}' ~/.ssh/config

(Note: I prefer ~ over $HOME when it's not in double-quotes, just in case of weird characters in the path.)