Minor improvements to legacy Perl code

We’re always working with code we didn’t write. You’ll spend far more time looking at code you didn’t write (or don’t remember writing) than you will spend writing new code.

Today I looked at an example Perl script that used 45 lines of code to pull the company associated with an OUI (Organizationally Unique Identifier) from a text file, given a MAC address.

I thought I could do slightly better.

find_mac_co.sh:

#!/bin/sh
OUI=$(echo "$1" | sed 's/[^A-Fa-f0-9]//g' | cut -c1-6)
awk -F "\t" -v IGNORECASE=1 -v OUI="$OUI" '$0 ~ OUI { print $3 }' ouidb.tsv
exit 0

Example run:

$ sh find_mac_co.sh 7c:ab:60:ff:ff:ff
Apple, Inc.

There’s probably a way to make the Perl version shorter too. I’m more familiar with bash and shell commands.

The biggest problem with this script is that it relies on an up-to-date list of OUIs. An even better way is to query an API:

find_mac_co_api.sh

#!/bin/sh
MACADDRESS="$1"
curl "https://api.maclookup.app/v2/macs/$MACADDRESS/company/name"
exit 0

Example run:

$ sh find_mac_co_api.sh 7c:ab:60:ff:ff:ff
Apple, Inc.