Crunch password list with exact length and number of letters and numbers known

i am trying to create a wordlist with crunch i only need all possible passwords exactly 20 digits/letters long with exactly 19 letters (a-z) and 1 number (0-9) is there a way to do that?

Sure you would do it like this:

crunch 20 20 abcdefghijklmnopqrs9 > passwordlist.txt

i need the command to make a 20 digit 19 letters one number calculation in the form of for example "abcdefghijklmnopqrst1" (places interchange) but with the complete alphabet and the numbers from 0 to 9. Is this command accurate for that?

If you know where the number is in the password you can download crunch 2.3 from crunch - wordlist generator | Get crunch - wordlist generator at SourceForge.net which supports specifying the locations of letters and numbers.

The number could be at any place in the password thats why i want to create an (19^26)*200 passwords list to have all possible combinations. I am just looking for the right command to exclude all passwords with more than one number.

Purehates command is probably the best way.

Also your formula is wrong. The formula to calculate the size of a wordlist is (x^y)*(y + 1) and you have x and y switched.
It should be num-of-chars ^ length so (27^20)*(20+1). So 890,214,323,779,540,273,800,183,097,221 bytes or 890,214 YB (Yottabytes). I don't think you have enough disk space for such a file.

thanks my mistake. According to one study, all the world's computers store only approximately 160 exabytes. i will try with smaller passwords and let one machine compute for one or two months and hope that i get lucky.

But could you explain the math a little bit?

I thought if i had 19 possible characters and 10 possible numbers with in a 20 digits/letters password and i could eliminate all possibilities i would have 19^26 possible combinations off letters * (10*20) numbers = 2.279.779.037.074.628.864 combinations. So only 2.3 EB (Exabytes).

Where did I get wrong?

Is this what you want?

Code:

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./crunch 20 20 -f charset.lst mixalpha-numeric | egrep '^[a-zA-Z]*[0-9][a-zA-Z]*$'

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All possible alphanumeric passwords exactly 20 characters in length and containing exactly one digit.

Thank you very much. Thats exactly what i wanted.

hi sorry to jump into this thread, but it is relevant to what i am also trying to find out

i want to make a wordlist of only uppercase A - Z and only 8 characters long, after reading the posts in the forum i found crunch and the command i needed to use to get what i want, thanks for that

my question is as follows, a 56gb file (the one i specified in crunch command) was made quite quickly in the crunch folder and the pc is plugging away still 18 hours later filling it with (i hope) all the possible combinations i asked for...

after reading this thread and another it seems that my resulting list should in fact be much, much bigger

am i correct with the following?

(26 ^ 8) * (8 * 1)
208827064576 * 9 = 1879443581184

like in the other post using google to do the diskspace math gives me
(26^8) * 9 bytes = 1.70934398 terabytes

if this is correct then i may as well abort as i have nowhere near this amount of space...