[OT] bash help

[Mike Wright]

Hey Gurus,

I'm trying to write a bash script.  There are 4 arrays: base10 base16 
base62 base70.

I want to match an array based on two digits provided by argument $1.

e.g.  getArray 70 would select base70

I've looked at substitutions, and {parameter,bash,brace} expansions.

This substitution look possible ${foo/%from/to}	(replace suffix) but 
that led me nowhere.

This looks like it should be *so easy*,

Amy takers?

Mike Wright

btw. this is a great bash cheatsheet  https://devhints.io/bash

[Samuel Sieb]

On 4/17/25 10:21 PM, Mike Wright wrote:
> I'm trying to write a bash script.  There are 4 arrays: base10 base16 
> base62 base70.
>
> I want to match an array based on two digits provided by argument $1.
>
> e.g.  getArray 70 would select base70

This should show what you need.

#/usr/bin/bash

array1=(1 2 3 4)
array2=(5 6 7 8)
array3=(9 10 11 12)

declare -n arr=array${1}
echo ${arr[$2]}

[Mike Wright]

On 4/17/25 23:23, Samuel Sieb wrote:
> declare -n arr=array${1}
> echo ${arr[$2]}

My hat is off to you, good sir.

I'd bumped into declare earlier today but couldn't grasp it in the 
context where it was used.

With your help I now have my password generator working.

pwgen [length] [radix]

I use radix=70 when I'm dealing with the uninformed sites that still 
insist on numbers, upper and lower alpha, and a "special" character.

I guess they never got the memo that a larger character set helps a 
little but a slightly longer password is exponentially stronger.

Thank you,
Mike Wright

[Patrick O'Callaghan]

On Fri, 2025-04-18 at 00:17 -0700, Mike Wright wrote:
> On 4/17/25 23:23, Samuel Sieb wrote:
> > declare -n arr=array${1}
> > echo ${arr[$2]}
>
> My hat is off to you, good sir.
>
> I'd bumped into declare earlier today but couldn't grasp it in the 
> context where it was used.
>
> With your help I now have my password generator working.
>
> pwgen [length] [radix]
>
> I use radix=70 when I'm dealing with the uninformed sites that still 
> insist on numbers, upper and lower alpha, and a "special" character.
>
> I guess they never got the memo that a larger character set helps a 
> little but a slightly longer password is exponentially stronger.

Not specific to your question, but I highly recommend shellcheck as a
way to catch errors and ambiguities in Bash scripts. I've found it to
be very helpful.

dnf info shellcheck

poc

[Joe Zeff]

On 04/17/2025 11:21 PM, Mike Wright wrote:
> btw. this is a great bash cheatsheet https://devhints.io/bash

So is this one: https://tldp.org/LDP/abs/html/