Number of non-empty elements

Number of non-empty elements

[Jesper Nygårds]

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Here's a very little thing that's annoying me.

I have a fairly long function where the result is stored in an array called
"mylines".

I want the function to return normally (status zero) if "mylines" contains
at least one non-empty element, and with non-zero otherwise.

This is the best I've come up with so far:

mylines=...

mylines=(${mylines}) # Remove empty elements
return $(( ${#mylines} == 0 ))

I particularly dislike that I have a separate line to remove empty lines.

Is there a more elegant, preferably one-line, solution to achieve this?

Re: Number of non-empty elements

[Daniel Shahaf]

Jesper Nygårds wrote on Tue, Sep 15, 2015 at 19:15:01 +0200:
> I have a fairly long function where the result is stored in an array called
> "mylines".
> 
> I want the function to return normally (status zero) if "mylines" contains
> at least one non-empty element, and with non-zero otherwise.

    return $(( $mylines[(I)?*] > 0 )0

The (I) modifier interprets the key as a pattern and returns the highest
index of a match, or 0 if there was no match.

Re: Number of non-empty elements

[Jesper Nygårds]

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Thank you, Daniel. That works great.


On Tue, Sep 15, 2015 at 11:43 PM, Daniel Shahaf <d.s@daniel.shahaf.name>
wrote:

> Jesper Nygårds wrote on Tue, Sep 15, 2015 at 19:15:01 +0200:
> > I have a fairly long function where the result is stored in an array
> called
> > "mylines".
> >
> > I want the function to return normally (status zero) if "mylines"
> contains
> > at least one non-empty element, and with non-zero otherwise.
>
>     return $(( $mylines[(I)?*] > 0 )0
>
> The (I) modifier interprets the key as a pattern and returns the highest
> index of a match, or 0 if there was no match.
>