Get MAC Address Using Shell Script

Get MAC address using shell script

Observe that the interface name and the MAC address are the first and last fields on a line with no leading whitespace.

If one of the indented lines contains inet addr: the latest interface name and MAC address should be printed.

ifconfig -a |
awk '/^[a-z]/ { iface=$1; mac=$NF; next }
    /inet addr:/ { print iface, mac }'

Note that multiple interfaces could meet your criteria. Then, the script will print multiple lines. (You can add ; exit just before the final closing brace if you always only want to print the first match.)

Linux Bash: List interfaces with IPs and Mac addresses

Write a script like this:

#!/bin/bash

printf '%10s %32s %32s\n' interface ipaddress macaddress
printf '%s\n' '----------------------------------------------------------------------------'
for each in $(ip address | grep -oP '(^[\d]+:\s)\K[\d\w]+'); do
  mac=$(ip address show ${each} | grep -oP '(?<=link/ether\s)\K[\da-f:]+|(?<=link/loopback\s)\K[\da-f:]+')
  for address in $(ip address show ${each} | grep -oP '(?<=inet\s)\K[\d.]+|(?<=inet6\s)\K[\da-f:]+'); do
    printf '%10s %32s %32s\n' ${each} ${address} ${mac}
  done
done

Output:

 interface                        ipaddress                       macaddress
----------------------------------------------------------------------------
        lo                        127.0.0.1                00:00:00:00:00:00
        lo                              ::1                00:00:00:00:00:00
      wlo1                      192.168.0.7                c8:aa:bb:cc:dd:ee
      wlo1        fe80::7aec:8287:9f45:d833                c8:aa:bb:cc:dd:ee
   docker0                       172.17.0.1                02:42:0d:0d:0d:0d
      tap0                        10.1.30.2                16:50:cc:cc:cc:cc
      tap0        fe80::10a9:d3ff:fece:57d7                16:50:cc:cc:cc:cc

Get only Mac address from IP (bash)

arp | awk '/192.168.15.1/{print $3;exit}'

By using this command, you will get only 1 mac.

If you want to adopt an input of bash script to be the addr, use the command below,

arp -n $1 | awk -v a=$1 '$0 ~ a{print $3;exit}'

use -v a=$1 to assign $1 of bash to the variable a in awk

Get mac address for alive interface

cat /sys/class/net/$(ip route show default | awk '/default/ {print $5}')/address

ip route show default | awk '/default/ {print $5}' prints your default interface name. Then you get your mac from /sys/class/net/IFACE_NAME/address

Trying to get BASH backup script to find an IP address based off known MAC address?

Try this pure Bash code:

declare -A found_mac2ip
while read -r ip _ mac; do
    [[ -n $mac ]] && found_mac2ip[$mac]=$ip
done <'found.devices'

while read -r ip mac domain source destination; do
    ip=${found_mac2ip[$mac]-$ip}
    # ... DO BACKUP FOR $ip ...
done <'known.targets'

• It first sets up a Bash associative array mapping found mac address to ip addresses.
• It then loops through the known.targets file and for each mac address it uses the ip address from the known.targets file if the mac address is listed in it. Otherwise it uses the ip address read from the known.targets file.

It's also possible to extract the "found" MAC and IP address information by getting it directly from the nmap output instead of from a `found.devices' file. This alternative version of the code does that:

declare -A found_mac2ip
nmap_output=$(sudo nmap -n -sP 192.168.2.0/24)
while IFS=$' \t\n()' read -r f1 f2 f3 f4 f5 _; do
    [[ "$f1 $f2 $f3 $f4" == 'Nmap scan report for' ]] && ip=$f5
    [[ "$f1 $f2" == 'MAC Address:' ]] && found_mac2ip[$f3]=$ip
done <<<"$nmap_output"

while read -r ip mac domain source destination; do
    ip=${found_mac2ip[$mac]-$ip}
    # ... DO BACKUP FOR $ip ...
done <'known.targets'

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