Найти все доменные имена второго уровня

#!/bin/bash
 
awk '{n=split($15, a, "\."); t=a[n-2]"."a[n-1]"."; arr[t]++}
        END{ for(i in arr)print i, arr[i]}' dns-tunneling.log

#!/bin/bash
 
awk '{tolower($15); n=split($15, a, "."); 
        if(length(a[n-1]) != 0 && length(a[n-2]) != 0)
        {t=a[n-2]"."a[n-1]"."; arr[t]++}}
        END{for(i in arr) 
            {print (i"\t"arr[i])}}' dns-tunneling.log |
sort -k 2rn |
awk '{print ("<"$1">""<""\t"">""<"$2">")}' > results.tsv
exit

#!/usr/bin/env pwsh
 
$o = @{}
 
(sls '((\w+)[.])\w+[.]\s' dns-tunneling.txt).foreach{ $o[ $_.Matches.Groups[2].value ]++ }
 
$o.GetEnumerator() | Sort-Object Value, Name -Descending

grep -o '\([^.[:blank:]]\+\.\)\{2\}\s' dns-tunneling.txt | sort | uniq -c | sort -k1nr

#!/usr/bin/env pwsh
 
grep -o '\([^.[:blank:]]\+\.\)\{2\}\s' dns-tunneling.txt | sort | uniq -c | sort -k1nr

grep -o '[[:alnum:]-]\+\.[[:alpha:]]\+\.\s' dns-tunneling.txt | sort | uniq -c | sort -k1nr

#!/bin/bash
 
# place your code here
# поместите сюда код
grep -o '\([^.[:blank:]]\+\.\)\{2\}\s' dns-tunneling.log |
tr [:upper:] [:lower:] |
sort |
uniq -c |
sort -k1nr |
awk '{print ($2"\t"$1)}' > results.tsv
exit

#!/bin/bash
 
# place your code here
# поместите сюда код
awk '{s=tolower($15); n=split(s, a, ".");
        if(length(a[n-1]) != 0 && length(a[n-2]) != 0)
        {t=a[n-2]"."a[n-1]"."; arr[t]++}}
        END{for(i in arr) {print (i"\t"arr[i])|"sort -k 2rn"}
}' dns-tunneling.log > results.tsv