Re: $${a,b} brace expansion flaw.

[alex xmb sw ratchev]

On Sat, Jan 20, 2024, 23:36 Greg Wooledge <greg@wooledge.org> wrote:

> On Sat, Jan 20, 2024 at 11:32:01PM +0100, alex xmb sw ratchev wrote:
> > ~ $ a=BaNaNa ; echo ${a,N}
> > BaNaNa
> > ~ $ a=BaNaNa ; echo ${a,,N}
> > Banana
>
> Yeah, I wasn't 100% correct in my previous message.  The single comma
> form only looks at the first character of the parameter's value.
>

very weird behavior
prolly cause it says , for once/beginning and ,, all
but thers a logic err
if i have a=NaNaNaNa and just wanna change first two N s lowercase ,
${a,NaN} sadly fails ( on more than one char )
where the wont be a ${a,,NaNa} version as its invalid
.. small detail

~ $ a=BaNaNa ; echo ${a,BaN}
BaNaNa

unicorn:~$ a='Baba Banana'
> unicorn:~$ echo "${a,B}"
> baba Banana
> unicorn:~$ a='aBaba Banana'
> unicorn:~$ echo "${a,B}"
> aBaba Banana
>
> I never use these, so I have to re-learn it every time it comes up.
>

good teach .. u aint alone  =))
greets

>