Braindump notes

In bash you can beautify your code by using logical operators instead of if/else statements:

A && B : If A is executed successfully then B is executed

A || B : If A fails, then B is executed

A; B : B is executed regardless of whether A was successful or not.

Simple example:

cat the file if it exists, and if not echo an error message:

If/else

if [ -e file.txt ]; then cat file.txt else echo "file.txt doesn't exist" exit 1; fi exit 0;

logical operators

cat file.txt 2>/dev/null || { echo "file.txt doesn't exist"; exit 1; }; exit 0

ps: I'm using 127.0.0.1 as the IP, switch with the target.

Host Discovery only

nmap -sn 127.0.0.1

Port Scanning only

nmap -Pn 127.0.0.1

List only targets.

nmap -sL 127.0.0.1

TCP SYN port scanning.

nmap -sS 127.0.0.1

UDP port scanning.

nmap -sU 127.0.0.1

With -sV, nmap checks for the version of the process running in the open TCP ports it finds.

nmap -sV 127.0.0.1

With -O, nmap performs OS detection of the target, through its TCP/IP stack.

nmap -O 127.0.0.1

NSE is Nmap's Scripting Engine, that provides scripts (LUA) that execute logic on Nmap's results. Some interesting categories I usually use is vuln and malware.

nmap --script vuln 127.0.0.1

For default scripts, but not intrusive ones: