Find subdomains using crt.sh

subdomains.sh

#!/bin/bash

# check curl exists
if ! command -v curl >/dev/null 2>&1
then
        sudo apt install -y curl
fi

# check pup exists
if ! command -v pup >/dev/null 2>&1
then
        sudo apt install -y pup 
fi

url=$1
out=$2

if [ -z "${out}" ];
then
        out="subdomains.txt"
fi

echo "Finding subdomains for $url"

curl -s "https://crt.sh?q=$url" | pup 'table table tbody tr td:nth-child(5) text{}' | sort | uniq > $out 

echo "Results saved into $out"