how to Generate a specifically formatted string

jamied_uk · 10-13-2022, 05:20 AM

How do I generate codes / strings with a specific format like

aaaAaaaaa1aa

12 chars long in total
Also with no duplicate chars (if pos)

where 1 is a number a is lower case and A is upper case? im using linux and like to use bash but pearl is just as good, I was trying to use crunch but that is way too long becuase of the aaaa crap that crunch spits out, any ideas?

NevemTeve · 10-13-2022, 05:32 AM

As a start, you can generate the lower-case letters this way (in bash):

Code:

for i in {a..z}; do echo $i; done | shuf | tr -d '\n' | cut -b-10

boughtonp · 10-13-2022, 07:27 AM

Why?

There are lots of different methods, but which ones are appropriate depends on what these codes are to be used for.

Is that example the specific format you want (4th char uppercase, 10th numeric), or will there be an arbitrary combination of "aA1" which needs parsing, etc?

Are you trying to generate unique ids, or passwords, or something else?

pan64 · 10-13-2022, 08:14 AM

so you have 5 fields. Generate those fields independently (depending on their requirements) and concatenate the results.

teckk · 10-13-2022, 09:09 AM

Quote:

12 chars long in total
Also with no duplicate chars (if pos)

Real simple example without any effort to make it concise.

Code:

a=({a..z})
b=({A..Z})
c=({0..9})

for i in {1..4}; do
    echo -n ${a["$[RANDOM % ${#a[@]}]"]}
    echo -n ${b["$[RANDOM % ${#b[@]}]"]}
    echo -n ${c["$[RANDOM % ${#c[@]}]"]}
done
echo ""

jamied_uk · 10-13-2022, 09:37 AM

Nice this is exaclty what I was looking for ty your a genius!

boughtonp · 10-13-2022, 10:20 AM

Quote:

Originally Posted by jamied_uk

Nice this is exaclty what I was looking for ty your a genius!

It is not exactly what you're looking for, because it allows duplicates which you claimed to want to avoid.

It is easy to prevent duplicates - and can be done in one line instead of nine - but whether it's a suitable approach depends on what you're doing, which is still unstated.

dugan · 10-13-2022, 11:35 AM

What’s crunch?

jamied_uk · 10-13-2022, 05:21 PM

I made this before i read replies from here and been refining it for a lil while i saw some great answers aswell, heres my final code

https://jnet.forumotion.com/t1886-ka...g-example#2931

As you asked what crunch is its for creating wordlists

Code:

#!/bin/bash
# (c)J~Net 2022
# jnet.club
# https://jnet.forumotion.com/t1887-using-bash-to-generate-keys-in-a-specific-format#2932
#
#
# ./key.sh 1000
#
#  cat keys.txt | grep "jn5W" 
#
echo "Hi $USER, Welcome To Key Gen V5 By J~Net 2022"
echo "Setting Up Pre Reqs!"
# Lets check if you have required apps installed to do this job...
input=`which perl`
if [ $input = "/usr/bin/perl" ]
then
    echo "You Have Perl Installed Already"
else
    echo "Installing Perl"
    sudo apt install -y perl
fi
#
input=`which crunch`
if [ $input = "/usr/bin/crunch" ]
then
    echo "You Have Crunch Installed Already"
else
    echo "Installing Crunch"
    sudo apt install -y crunch
fi
#
if [ -z "$1" ]
then
	echo "How Many keys You Want?"
	read num

else
        num=$1

fi
#
file="wordlists/1.txt"
if [[ -f $file ]]
then
    echo ""
else
    sudo mkdir wordlists
    touch $file
    crunch 3 3 abcdefghijklmnopqrstuvwxyz -d 1 -t @@% | perl -ne 'print unless /([A-Z]).*\1/' > $file
fi
#
file="wordlists/2.txt"
if [[ -f $file ]]
then
    echo ""
else
    sudo mkdir wordlists
    touch $file
    crunch 3 3 abcdefghijklmnopqrstuvwxyz -d 1 -t ,@@ | perl -ne 'print unless /([A-Z]).*\1/' > $file
fi
#
#
file="wordlists/3.txt"
if [[ -f $file ]]
then
    echo ""
else
    sudo mkdir wordlists
    touch $file
    crunch 3 3 abcdefghijklmnopqrstuvwxyz -d 1 -t @@@ | perl -ne 'print unless /([A-Z]).*\1/' > $file
fi
#
file="wordlists/4.txt"
if [[ -f $file ]]
then
    echo ""
else
    sudo mkdir wordlists
    touch $file
    crunch 3 3 abcdefghijklmnopqrstuvwxyz -d 1 -t %@@ | perl -ne 'print unless /([A-Z]).*\1/' > $file
fi
#
i=0
echo "Getting $num Random Wifi keys"
   	
while [ $i -lt $num ]
do
   	echo ""
	i1=`shuf -n 1 wordlists/1.txt`
	i2=`shuf -n 1 wordlists/2.txt`
	i3=`shuf -n 1 wordlists/3.txt`
	i4=`shuf -n 1 wordlists/4.txt`

	echo "$i1$i2$i3$i4" >> keys.txt
	echo "Generating New Wifi Key $i of $num Is: $i1$i2$i3$i4"
	
   ((i++))

done