How to modify input from ifconfig in awk

You may try this awk:

ifconfig |awk -v OFS='\t' 'BEGIN {ip=mac=" "; print "inet_name", "ip_ddress", "mac_address"} /^[[:alnum:]]+: / {if (inet) {print inet, ip, mac; ip=mac=" "; inet=""} if ($1 !~ /^lo/) inet=$1} inet && /^[[:blank:]]+inet / {ip=$1 " " $2} inet && /^[[:blank:]]+ether / {mac=$1 " " $2} END {if (inet) print inet, ip, mac}' | column -t -s $'\t'inet_name  ip_ddress             mac_addressenp2s0f1:                        ether xx:xx:xx:xx:xx:xxwlp3s0:    inet xxx.xxx.xxx.xxx  ether xx:xx:xx:xx:xx:xx

To make it more readable:

ifconfig |awk -v OFS='\t' '# set output field separator to tabBEGIN {   # initialize ip and mac variables   ip = mac = " "   print header record   print "inet_name", "ip_ddress", "mac_address"}/^[[:alnum:]]+: / {            # if no blank at start   if (inet) {                 # print full record if not first time      print inet, ip, mac      ip = mac = " "           # reset variables      inet = ""   }   if ($1 !~ /^lo/)            # if not starting with "lo"      inet = $1                # save inet name in var inet}inet && /^[[:blank:]]+inet / { # if inet is set and we have inet after spaces   ip = $1 " " $2              # save $1 " " $2 in ip variable}inet && /^[[:blank:]]+ether / {#  if inet is set and we have ether after spaces   mac = $1 " " $2             # save $1 " " $2 in mac variable}END {   if (inet)                   # if inet is not blank      print inet, ip, mac      # print full record}' | column -t -s $'\t'

• column comman has been used for tabular output.

Instead of parsing the output of ifconfig which is not a reliable API data exchange, you could use the ip tool instead with its -j or -json option to output JSON formatted answer that can be reliably parsed with a tool like jq or any programming language with a JSON parser.

Here it is as a one-liner:

ip -json addr show |  jq -r '"name\tip_address\tmac_address", ( .[] | if (.addr_info | length) > 0 then .ifname + "\t" + (.addr_info[] | select(.family=="inet")).local + "\t" + .address else empty end )'

Or commented stand-alone jq script:

#!/usr/bin/env -S jq -rf# Print header line"name\tip_address\tmac_address",(  # Stream all results array  .[] |  # If interface has a non-empty addr_info array  if (.addr_info | length) > 0  then    # Print interface name as first column    .ifname + "\t" + (    # Print ipv4 address as second column      .addr_info[] | select(.family=="inet")    ).local + "\t" +    # Print mac address as third column    .address  else  # Do nothing if interface has no ip address    empty  end)

Example output:

name    ip_address      mac_addresslo      127.0.0.1       00:00:00:00:00:00enp4s0  192.168.1.10    00:24:1d:00:00:00virbr0  192.168.122.1   52:54:00:00:00:00