From: Ross Bamford <rosco@...>
Date: 2005-12-18T22:38:10+09:00
Subject: Re: Spawning

On Sun, 18 Dec 2005 12:58:09 -0000, Stefan Lang <langstefan@gmx.at> wrote:

> On Sunday 18 December 2005 13:43, Steve Litt wrote:
>> On Sunday 18 December 2005 04:46 am, Florian Frank wrote:
>> > Steve Litt wrote:
>> > >I converted the array of arguments to a string, and it worked.
>> > > But it should have worked the other way too. What am I missing?
>> >
>> > exec *argarray
>>
>> Confirmed! Thanks Florian.
>>
>> Now I can run a command with several words quoted together to make
>> one argument.
>>
>> Curious -- what does the asterisk do to make it work when it didn't
>> work without the asterisk. What does the asterisk do? I know it
>> doesn't mean "the contents of this address" -- that's another
>> language :-)
>
> It flattens the array (argarray) into an argument list.
> This means the first element of argarray becomes the first
> argument to exec, the second element of argarray becomes
> the second argument to exec and so on.
>

I've seen it also called the 'splat' operator, and (I think?) David Black  
called it the 'unary unarray' operator, which I a good name for it. It  
doesn't just work with method arguments, and it doesn't just work with  
arrays:

	p = *File.open('/etc/passwd')

gives an array of all the lines in the file. I was most impressed when I  
found that out recently ;)

(p.s. I'm not advocating that method of reading files _at all_ - it's just  
an example)

-- 
Ross Bamford - rosco@roscopeco.remove.co.uk