• Read the above.

No Answer

• Read the above. 

No Answer

• Read the above

No Answer

• Is there a difference between egrep and fgrep? (Yea/Nay)

Answer : YEA

• Which flag do you use to list out all the lines NOT containing the 'PATTERN'?

Answer : -v

• Download the above given file and answer the following questions.

No Answer

• What user did you find in that file?

grep -i "user" gre.txt 
uxx6x84XZw5VsQTHzVMN7F6fuxx6x84XZw5VsQTHzVMN7F6fuxx6x84XZw5VsQTHzVMN7F6fuxx6x84XZw5VsQTHzVMN7FuSeR:bobthebuilder6fuxx6x84XZw5VsQTHzVMN7F6fuxx6x84XZw5VsQTHzVMN7F6fuxx6x84XZw5VsQTHzVMN7F6f

Answer : bobthebuilder

• What is the password of that user?

grep -i "pass" gre.txt 
qEqbDkrSFzmhRdDSQNWqaMTXqEqbDkrSFzmhRdDSQNWqaMTthispAsSwOrDistoosensitive:'LinuxIsGawd'XqEqbDkrSFzmhRdDSQNWqaMTXqEqbDkrSFzmhRdDSQNWqaMTXqEqbDkrSFzmhRdDSQNWqaMTXqEqbDkrSFzmhRdDSQNWqaMTXqEqbDkrSFzmhRdDSQNWqaMTX

Answer : LinuxIsGawd

• Can you find the comment that user just left?

grep "comment" grep.txt
8gmdNXTN4gn2u73SuX5cewcM8gmdNXTN4gn2comment:'fs0ciety'u73SuX5cewcM8gmdNXTN4gn2u73SuX5cewcM8gmdNXTN4gn2u73SuX5cewcM8gmdNXTN4gn2u73SuX5cewcM8gmdNXTN4gn2u73SuX5cewcM8gmdNXTN4gn2u73SuX5cewcM

Answer : fs0ciety

• Press any key to continue... 

No Answer

• Read the Above.

No Answer

• Run tr --help command and tell how will you select any digit character in the string ?

tr --help
Usage: tr [OPTION]... SET1 [SET2]
Translate, squeeze, and/or delete characters from standard input,
writing to standard output.

  -c, -C, --complement    use the complement of SET1
  -d, --delete            delete characters in SET1, do not translate
  -s, --squeeze-repeats   replace each sequence of a repeated character
                            that is listed in the last specified SET,
                            with a single occurrence of that character
  -t, --truncate-set1     first truncate SET1 to length of SET2
      --help     display this help and exit
      --version  output version information and exit

SETs are specified as strings of characters.  Most represent themselves.
Interpreted sequences are:

  \NNN            character with octal value NNN (1 to 3 octal digits)
  \\              backslash
  \a              audible BEL
  \b              backspace
  \f              form feed
  \n              new line
  \r              return
  \t              horizontal tab
  \v              vertical tab
  CHAR1-CHAR2     all characters from CHAR1 to CHAR2 in ascending order
  [CHAR*]         in SET2, copies of CHAR until length of SET1
  [CHAR*REPEAT]   REPEAT copies of CHAR, REPEAT octal if starting with 0
  [:alnum:]       all letters and digits
  [:alpha:]       all letters
  [:blank:]       all horizontal whitespace
  [:cntrl:]       all control characters
  [:digit:]       all digits
  [:graph:]       all printable characters, not including space
  [:lower:]       all lower case letters
  [:print:]       all printable characters, including space
  [:punct:]       all punctuation characters
  [:space:]       all horizontal or vertical whitespace
  [:upper:]       all upper case letters
  [:xdigit:]      all hexadecimal digits
  [=CHAR=]        all characters which are equivalent to CHAR

Translation occurs if -d is not given and both SET1 and SET2 appear.
-t may be used only when translating.  SET2 is extended to length of
SET1 by repeating its last character as necessary.  Excess characters
of SET2 are ignored.  Only [:lower:] and [:upper:] are guaranteed to
expand in ascending order; used in SET2 while translating, they may
only be used in pairs to specify case conversion.  -s uses the last
specified SET, and occurs after translation or deletion.

GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
Full documentation at: <http://www.gnu.org/software/coreutils/tr>
or available locally via: info '(coreutils) tr invocation'

Answer : :digit:

• What sequence is equivalent to [a-zA-Z] set ?

Answer : :alpha:

• What sequence is equivalent to selecting hexadecimal characters ?

Answer : :xdigit:

• Read the above.

Answer : Hardware

• Download the above given file, and use awk command  to print the following output:
  
  ippsec:34024
  john:50024
  thecybermentor:25923
  liveoverflow:45345
  nahamsec:12365
  stok:1234

awk 'BEGIN{FS=" "; OFS=":"} {print $1,$4}' awk.txt
ippsec:34024
john:50024
thecybermentor:25923
liveoverflow:45345
nahamsec:12365
stok:1234

Well, i also tried the below command that return the good lines :

awk 'BEGIN{OFS=":"} {print $1,$4}' awk.txt

But this was not the answer needed.

Answer : awk 'BEGIN{FS=" "; OFS=":"} {print $1,$4}' awk.txt

• How will you make the output as following (there can be multiple; answer it using the above specified variables in BEGIN pattern):
  
  ippsec, john, thecybermentor, liveoverflow, nahamsec, stok,

awk 'BEGIN{ORS=","} {print $1}' awk.txt
ippsec,john,thecybermentor,liveoverflow,nahamsec,stok,

Answer : awk 'BEGIN{ORS=","} {print $1}' awk.txt

• How would you substitute every 3rd occurrence of the word 'hack' to 'back' on every line inside the file file.txt ?

Answer : sed 's/hack/back/3g' file.txt

• How will you do the same operation only on 3rd and 4th line in file.txt?

Answer : sed '3,4 s/hack/back/3g' file.txt

• Download the given file, and try formatting the trailing spaces in sed1.txt with a colon(:).

root@ip-10-10-89-122:~/Desktop# sed 's/ */:/g' sed1.txt
:u:s:e:r:p:a:s:s:w:o:r:d:
:h:a:x:o:r:l:s:a:t:s:d:f:
:n:o:m:a:n:d:a:d:x:i:f:t:o:x:1:2:3:
:n:o:b:i:t:a:s:h:i:z:u:k:a:<:3:
:x:a:d:m:i:n:x:n:e:e:d:m:e:?:$:
:p:e:t:e:r:p:a:n:T:i:n:k:e:r:B:e:l:l:6:9:
:s:a:t:a:n:G:O:A:T:

Answer : sed 's/ */:/g' sed1.txt

• View the  sed2 file in the directory. Try putting all alphabetical values together, to get the answer for this question.

root@ip-10-10-89-122:~/Desktop# sed 's/[0-9]*//g' sed2.txt
CONGRATULATIONS
YOU
MADE
IT
THROUGH
THIS
SMALL
LITTLE
CHALLENGE

Answer : CONGRATULATIONS YOU MADE IT THROUGH THIS SMALL LITTLE CHALLENGE

• What pattern did you use to reach that answer string ?

The regex use in the previous question works, but is not the one which was intended here, so i just replace the regex expression by [[:digit:]].

root@ip-10-10-89-122:~/Desktop# sed 's/[[:digit:]]//g' sed2.txt 
CONGRATULATIONS
YOU
MADE
IT
THROUGH
THIS
SMALL
LITTLE
CHALLENGE

Answer : 's/[[:digit:]]//g'

• Alternatively, you can use tr to remove all the digits, and then pipe the output in sed to remove trailing whitespaces.

                    cat sed2.txt | tr '[:digit:]' ' ' | sed 's/  *//g'
                  

[Update] Another good way suggested by a room do-er. You can simply use tr -d command to delete all the digits from the file.

                    cat sed2.txt | tr -d '[:digit:]'
                  

No Answer

• What did she sed?(In double quotes)

Just a reference from the first line of this task.

Answer : "That's What"

• Read the above.

No Answer

• You're working in a team and your team leader sent you a list of files that needs to be created ASAP within current directory so that he can fake the synopsis report (that needs to be submitted within a minute or 2) to the invigilator and change the permissions to read-only to only you(Numberic representation). You can find the files list in the "one" folder.
  Use the following flags in ASCII order:
  
      - Verbose
      - Take argument as "files"
  

Few keywords in this question : read-ony to you (chomd 400), verbose and take argument as "files" (-I file -t) in ASCII.

Answer : cat file | xargs -I files -t sh -c “touch files; chmod 400 files”

• Your friend trying to run multiple commands in one line, and wanting to create a short version of rockyou.txt, messed up by creating files instead of redirecting the output into "shortrockyou". Now he messed up his home directory by creating a ton of files. He deleted rockyou wordlist in that one liner and can't seem to download it and do all that long process again.
  He now seeks help from you, to create the wordlist and remove those extra files in his directory. You being a pro in linux, show him how it's done in one liner way.
  Use the following flags in ASCII order:
  
      - Take argument as "word"
      - Verbose
      - Max number of arguments should be 1 in for each file

You can find the files for this task in two folder.

Few keywords too here : argument as word (-I word), max number of arguments equal 1 (-n 1) and verbose again (-t)

Answer : ls | xargs -I word -n 1 -t sh -c ‘echo word >> shortrockyou; rm word’

• Which flag to use to specify max number of arguments in one line.

Answer : -n

• How will you escape command line flags to positional arguments?

Answer : --

• Read the above. 

No Answer

• Download the file given for this task, find the uniq items after sorting the file. What is the 2271st word in the output ?
  

root@ip-10-10-230-20:~/Desktop# sort test.test | uniq > sorted.txt
root@ip-10-10-230-20:~/Desktop# sed -n '2271p' sorted.txt 
lollol

Answer : lollol

What was the index of term 'michele' ?

Use grep on the sorted file to get the word requested and the -n flag the print the line number :

root@ip-10-10-230-20:~/Desktop# grep -n 'michele' sorted.txt 
2550:michele

Answer : 2550

• Read the above

No Answer

• Which flag allows you to limit the download/upload rate of a file?

Just take a look on the table above ;-)

Or you can choose the --help way :

root@ip-10-10-230-20:~/Desktop# curl --help | grep 'limit'
     --limit-rate <speed> Limit transfer speed to RATE
 -Y, --speed-limit <speed> Stop transfers slower than this
 -y, --speed-time <seconds> Trigger 'speed-limit' abort after this time

Answer : --limit-rate

• How will you curl the webpage of https://tryhackme.com/ specifying user-agent as 'juzztesting'

root@ip-10-10-230-20:~/Desktop# curl --help | grep 'agent'
 -A, --user-agent <name> Send User-Agent <name> to server

Answer : curl -A juzztesting https://tryhackme.com/

• Can curl perform upload operations?(Yea/Nah)

root@ip-10-10-230-20:~/Desktop# curl --help | grep 'upload'
 -a, --append        Append to target file when uploading
     --crlf          Convert LF to CRLF in upload
 -T, --upload-file <file> Transfer local FILE to destination

Answer : YEA

• Read the above

No Answer

• How will you enable time logging at every new activity that this tool initiates?

root@ip-10-10-230-20:~/Desktop# wget --help | grep 'time'
  -N,  --timestamping              don't re-retrieve files unless newer than
                                     requests in timestamping mode
       --no-use-server-timestamps  don't set the local file's timestamp by
  -T,  --timeout=SECONDS           set all timeout values to SECONDS
       --dns-timeout=SECS          set the DNS lo

Answer : -N

• What command will you use to download https://xyz.com/mypackage.zip using wget, appending logs to an existing file named "package-logs.txt"

root@ip-10-10-230-20:~/Desktop# wget --help | grep 'append'
  -a,  --append-output=FILE        append messages to FILE

Answer : wget -a package-logs.txt https://xyz.com/mypackage.zip

• Write the command to read URLs from "file.txt" and limit the download speed to 1mbps.

root@ip-10-10-230-20:~/Desktop# wget --help | grep 'download'
  -i,  --input-file=FILE           download URLs found in local or external FILE
  -nc, --no-clobber                skip downloads that would download to
  -c,  --continue                  resume getting a partially-downloaded file
       --start-pos=OFFSET          start downloading from zero-based position OFFSET
       --spider                    don't download anything
       --limit-rate=RATE           limit download rate to RATE
[...]

root@ip-10-10-230-20:~/Desktop# wget --help | grep 'limit'
  -t,  --tries=NUMBER              set number of retries to NUMBER (0 unlimits)
       --limit-rate=RATE           limit download rate to RATE

Answer : wget -t file.txt --limit-rate=1

• Read the above. 

No Answer

• How will you seek at 10th byte(in hex) in file.txt and display only 50 bytes ?

Offset 10 -> -s 0xA
display 50 bytes -> length of 50 bytes -> -l 50 -b

Answer : xxd -s 0xA -l 50 -b file.txt

• How to display a n bytes of hexdump in 3 columns with a group of 3 octets per row from file.txt ? (Use flags alphabetically)

Take a look in the table and the quick note just below the table !

Answer : xxd -g 3 -c 3 file.txt

• Which has more precedence over the other -c flag or -g flag ?

The note below the table give us the answer : "[...] -c flag precedes over -g."

Answer : -c

• Download the file and find the value of flag.

root@ip-10-10-230-20:~/Desktop# xxd -p -r flag.txt | cat
flag{wh3sdw0lw1gl9oqasad2fs48as}

Answer : flag{wh3sdw0lw1gl9oqasad2fs48as}

• Press F to pay respect

F : Easy nah ?

Answer : F