topic Re: want a64l like function in shell script in Operating System - HP-UX

want a64l like function in shell script

arking1981 — Tue, 16 Aug 2011 13:44:00 GMT

Dear all,

please suggest if there is any utility in shell script to do the function of a64l.

I need to convert the 64based ascii password characters to interger.

Any available utility or methods? Please advise.

Thanks and Regards

Kang

Re: want a64l like function in shell script

James R. Ferguson — Tue, 16 Aug 2011 14:04:22 GMT

Hi:

I believe that you are going to have to write your own C code using 'a64l(3C)' :

http://bizsupport.austin.hp.com/bc/docs/support/SupportManual/c02252931/c02252931.pdf

Regards!

...JRF...

Re: want a64l like function in shell script

arking1981 — Wed, 17 Aug 2011 04:28:07 GMT

thanks. but I must deal with it in shell script.

I only need to decode at most 1 character in one time, not too complicated, and I am thinking a couple of possible solutions

1 create an array containing all base64 ascii which is "./0-9A-Za-z", then use cut to extract ervery single char and compare it with input to decide the index, which will be the wanted integer

2 devide 64base ascii into 5 categories

. for 0

/ for 1

0-9: simply plus 2 for 2-11

A-Z: convert it to ASCII(65-90) and minus 53 for 12-37

a-z: convert it to ASCII(97-122) and minus 59 for 38-63

3 use some utility to tell the index of input character in string"./0-9A-Za-z"

I don't know if shell has such an utility. I though about grep, sed, awk and not find any way to do it.

Do you know any tool to achieve such a task?

regards

kang

Re: want a64l like function in shell script

Dennis Handly — Wed, 17 Aug 2011 09:03:29 GMT

>3 use some utility to tell the index of input character in string"./0-9A-Za-z"

>I thought about grep, sed, awk and not find any way to do it.

grep -n can do it but would be expensive. ;-)

But you can use awk's index:

awk -v char=$char '

BEGIN {
print index("./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz", char)-1;
exit 0
} ' /dev/null

Re: want a64l like function in shell script

arking1981 — Wed, 17 Aug 2011 09:27:40 GMT

it is amazing........ thanks a ton. I kudos you, thanks