Re: bash conversion trouble.

[Ray Andrews <rayandrews@eastlink.ca>]

On 25/02/17 09:02 AM, Bart Schaefer wrote:
> On Feb 25,  8:24am, Ray Andrews wrote:
> }
> } Just curious: why would that have been changed?
>
> This comes from zsh's original heritage as a bourne-shell-like shell
> intended for students who were trained on BSD csh.  Also this happened
> before ksh was widely available outside an AT&T research lab so there
> was no bourne-shell array syntax to "change".
>
> Exactly why csh adopted 1-based arrays is probably lost to history at
> this point, but I suspect the argument goes something like this.
>
> When invoking a script e.g. "prog this is a test", internally $0 is
> "prog" and the arguments are $1 = this, $2 = is, etc.  Therefore when
> referring to the positional paramters, counting always starts from 1.
> Consequently it "makes sense" to have other arrays also count from 1,
> so that e.g.
>
>      newarray=("$@")
>      if [ "$newarray[1]" = "$1" ]; then echo copied correctly; fi
>
> It's strange to have to adjust thinking to zero-based for other arrays
> when the most obvious default array seems to start at 1.
>
Interesting.  So bash and ksh went one way an zsh and csh went the 
other.  Obviously the decision was made in the context of the time, but 
I'd have expected zsh to go with bash.  One hears nothing but bad things 
about csh.  But it's good to stop looking for some deep logic to it and 
just realize that it's arbitrary. The only real irritation is that it 
isn't consistent.  Yeah, why not just use natural counting?   That 
array[9] is the tenth element has always seemed a bit dumb but I'm used 
to it from C.