Re: On using $_ in subroutines

> Bryan Harris wrote:
>> 
>> John W. Krahn wrote:
>>> 
>>> Bryan Harris wrote:
>>>> 
>>>> ... but by modifying $_ I was clobbering $_ elsewhere in the larger
>>>> program!
>>> Yes because $_ is a special global variable.  This effect is called
>>> "action at a distance" which is why it is better to use named lexically
>>> scoped variables instead of $_.
>> 
>> I have the Perl Bookshelf on CD (and perldoc, obviously) -- where can I read
>> more about this?
> 
> perldoc perlvar
> 
> http://shoebox.net/articles/perl-warts.html
> http://en.wikipedia.org/wiki/Action_at_a_distance_(computer_science)

Great info, thanks.

Curiously, perlvar seems to recommend localizing $_ with "local", but I
thought I read somewhere to never use local and only use my.  I still don't
understand how those two are different.



>>>> Oddly, perl won't let me do "my ($_) = shift;", so I'm stuck having to use
>>>> another variable.
>>> Perl 5.10 *will* let you do "my $_".
>> 
>> Why is perl on OS X still at 5.8.8?  It's free, right?  why wouldn't Apple
>> include the latest one?  (I know this isn't an Apple list, just wondering if
>> anyone knows.)
> 
> Perl 5.10 is still at the .0 stage (5.10.0) and a lot of people like to
> wait until software has progressed past the .0 phase.

Makes sense.  What happened to Perl 5.9?

- Bryan




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