Re: ${var: -1:1} vs. ${var:-1:1}

[Ray Andrews <rayandrews@eastlink.ca>]

On 17/11/12 05:31 PM, Bart Schaefer wrote:
> On Nov 17,  2:56pm, Ray Andrews wrote:
> } Subject: Re: ${var: -1:1} vs. ${var:-1:1}
> }
> } > if you don't put a space there then the parser thinks that this the
> } > "${variable:-default} syntax which means "expands to the variable's
> } > content if the variable is set and to 'default' if it is unset".
> } >
> } > So the '1:1' is interpreted as the 'default'. You probably never saw
> } > that result because you were trying to extract the last character from
> } > a string, meaning you always used a variable that was set.
> } >
> } I see.  But it's still lousy syntax IMHO.
>
> Well, the var:-word syntax long predates :N:M for string slicing.  Zsh
> actually can (and always has) used just ${var[-1]} for the last character
> of a string, the :N:M syntax was invented by bash and merely adopted by
> zsh for compatibility.
>
Yeah, I guess it's one of those things where it would be different if 
the whole thing could be rethought, but traditions must be 
accommodated.  I guess if you want a blank sheet of paper, that's when 
you start again with a new shell. But thanks for '${var[-1]}' that's a 
better syntax all around.