Word split

Word split

[Bernd Eggink]

Hi,

I have a problem with word splitting in 3.1.2:

	x='a::b'
	y=(${(s(:)x})

I wanted $y to hold 3 elements, with an empty $y[2], but the result is
an array with 2 elements, 'a' and 'b'. This would be OK if at least 

	y=("${(@s(:)x}")

gave 3 elements, but it doesn't either. This is inconsistent with the
behaviour of

	setopt shwordsplit; IFS=:; y=($x) 

which results in an array of length 3.

Any comments?

	Bernd

--
Bernd Eggink
Regionales Rechenzentrum der Uni Hamburg
eggink@rrz.uni-hamburg.de
http://www.rrz.uni-hamburg.de/eggink/BEggink.html

Re: Word split

[Bart Schaefer]

On Nov 6,  4:49pm, Bernd Eggink wrote:
} Subject: Word split
}
} 	x='a::b'
} 	y=(${(s(:)x})
                  ^
        y=(${(s(:))x})
                  ^
} I wanted $y to hold 3 elements, with an empty $y[2], but the result is
} an array with 2 elements, 'a' and 'b'. This would be OK if at least 
} 
} 	y=("${(@s(:)x}")
                    ^
  	y=("${(@s(:))x}")
                    ^
} gave 3 elements, but it doesn't either.

I thought perhaps this was a problem with using it in the array context,
but ${(ws(:))#x} yeilds 2, so it really is dropping the empty word when
doing the split.

While we're on the subject, is there any chance the manual could get some
more examples added to the parameter expansion section?  It's really not
very easy to understand from the one-line descriptions what something like
${(SI(1)B)x%:} will produce.

"Include the index of the beginning of the match in the result."

Whaddaya mean, "include?"

Well, what you mean is that if you use multiple flags, you get multiple
words in the result:

    zagzig[144] echo ${(SI(1)BE)x%:}
    3 4

But the order of the flags doesn't make any difference:

    zagzig[145] echo ${(SI(1)EB)x%:}
    3 4

And nowhere is it explained what order they're going to show up in:

    zagzig[146] echo ${(SI(1)BR)x%:}
    a:b 3
    zagzig[147] echo ${(SI(1)MR)x%:}
    : a:b
    zagzig[148] echo ${(SI(1)RBM)x%:}
    : a:b 3
    zagzig[149] echo ${(SI(1)RBMN)x%:}
    : a:b 3 1
    zagzig[150] echo ${(SI(1)RBMNE)x%:}
    : a:b 3 4 1

Lots of zsh's features lurk behind this kind of veil of semidocumentation.

-- 
Bart Schaefer                                 Brass Lantern Enterprises
http://www.well.com/user/barts              http://www.brasslantern.com