Authored Comments

For the TAB example, you can place all the sed operations in one argument instead of two with the compound semicolon ";" separating them eg:
sed -e 's/^/>/; s/\t/ /g' Makefile

Another useful one is adding a REGEX first, similar like grepping, before applying the operators on a line eg:
sed '/REGEX/ s/^/>/; s/\t/ /g' Makefile

Below might come in handy if install nmap:

$ sudo nmap --script broadcast-dhcp-discover
Starting Nmap 7.80 ( ) at 2022-07-22 10:44 CEST
Pre-scan script results:
| broadcast-dhcp-discover:
| Response 1 of 1:
| IP Offered:
| DHCP Message Type: DHCPOFFER
| Server Identifier:
| IP Address Lease Time: 2m00s
| Renewal Time Value: 1m00s
| Rebinding Time Value: 1m45s
| Subnet Mask:
| Broadcast Address:
| Domain Name:
| NTP Servers:
| Domain Name Server:,
|_ Router:

And one can learn allot from a public IP ;)

$ dig +short -x

$ sudo nmap -sS
Starting Nmap 7.80 ( ) at 2022-07-22 09:44 CEST
Nmap scan report for (
Host is up (0.11s latency).
Not shown: 994 filtered ports
22/tcp open ssh
25/tcp open smtp
80/tcp open http
143/tcp open imap
443/tcp closed https
993/tcp open imaps

$ echo | nc -v 22
Connection to 22 port [tcp/ssh] succeeded!

$ curl -I
HTTP/1.1 200 OK
Date: Fri, 22 Jul 2022 07:45:28 GMT
Server: Apache/2.4.54 (Fedora Linux) OpenSSL/3.0.5
X-Powered-By: PHP/8.1.8
Link: ; rel=""
Content-Type: text/html; charset=UTF-8

$ nc 25 <<< 'helo me.'
554 ESMTP not accepting messages
250 Hello XXXX [XXXX], pleased to meet you

$ whois
Organization: AT&T Corp. (AC-3280)

$ whois
Registrar: Google LLC