Level 8

Login

SSH: ssh [email protected] -p 2220

Challenge URL: https://overthewire.org/wargames/bandit/bandit9.html

Task

The password for the next level is stored in the file data.txt and is the only line of text that occurs only once.

Solution

Let's see the files present:

bandit8@bandit:~$ ls
data.txt
bandit8@bandit:~$ wc -l data.txt
1001 data.txt

Use sort to sort the words in dictionary order so that repeated words will be together.
Next use uniq to see the unique lines and count the number of words.
uniq -u will directly give the unique word in the file, or you can display the count and grep 1 from there.

cat data.txt | sort -f -d | uniq -u
# or
cat data.txt | sort -f -d | uniq -c | grep " 1 "

-f is to ignore the case of the letter and -d is for dictionary ordering.
-c is to display the count, i.e. number of times it has been repeated (not used here).

One liner: cat data.txt | sort -f -d | uniq -u