Re: [Sheflug] Perl tips

[Alex Hudson <home [at] xxxxxxxxxxxxxx>]

On Mon, Nov 25, 2002 at 03:47:33PM +0000, Dave Mitchell wrote:
> Usually the easiest thing is to build a hash of sort keys first:
> 
>     @files = ...
>     foreach ( [at] files) {
> 	/-(\d\d)-(\d\d)-(\d\d\d\d)$/ or die "bad filename: $_\n";
> 	$dates{$_} = "$3$2$1";
>     }
>     @sorted_files = sort { $dates{$a} cmp $dates{$b} }  [at] files;

Or, you can just write a function:

sub file2num {
	my ($file) = @_;
	return if ($file !~ /-(\d\d)-(\d\d)-(\d{4})$/);
	return "$2$3$4";
}

my @list = sort { file2num($a) <=> file2num($b) } sort  [at] files;

Depending on how long the list is, a function is usually a better idea,
since you could conceivably have a very long list :o)

BTW, I think you want the ufo operator in your example, like mine?

Cheers,

Alex.
___________________________________________________________________

Sheffield Linux User's Group -
http://www.sheflug.co.uk/mailfaq.html

  GNU the choice of a complete generation.