UNIX for Beginners Questions & Answers

- {fqdn: "server-01" , ip: "server-01"}
- {fqdn: "server-02" , ip: "server-02"}
- {fqdn: "server-03" , ip: "server-03"}
- {fqdn: "server-04" , ip: "server-04"}

cat /tmp/new_server
server-05
server-06
server-07
server-08

#!/bin/bash
# glob-match for a server name
server_m="server-[0-9][0-9]"
while IFS= read -r line
do
  if [[ $line == *$server_m* ]]
  then
    read server_n <&3
    line=${line//$server_m/$server_n}
  fi
  echo "$line"
done < your_example 3< new_server

awk '
BEGIN {
# ERE-match for a server name
  server_m="\<server-[0-9]+"
}
$0~server_m {
  getline server_n < servers
  gsub(server_m,server_n,$0)
}
{ print }
' servers="new_server" your_example

paste file[12] | awk '{gsub (/server-0[0-9]/, $NF); NF--} 1'

paste file[12] | sed -r 's/^(.*)((server-0)[0-9])(.*)\2(.*)(\3[0-9])/\1\6\4\6\5/'