[plug] A question for perl hackers

[Brian Tombleson]

> I am trying to grab the filesize in bytes from a listing like:
>    310272 Aug 21 22:18 inbox
>   5193576 Jul  7 09:45 lyndon
>         0 Aug 12 09:58 mailing lists
>     32720 Jun 10 20:10 mchoice
>     46513 Aug 16 16:18 netvigator
>         0 Aug 21 20:04 outbox
>  10069208 Aug 21 20:04 sent-mail
>   2377093 Aug 21 19:33 trash
>
> As I step through an array with foreach I would like to assign the
filesize
> in bytes (the first number) to a variable.  I need to match:

Well, checking your assumptions you can make that pretty easy ..
Assumptions:
  Format is always consistent : _X_M_D_T_F*
      where: _ is any amount of white space
            X is a number
            M is the month
            D is the day
            T is the time (or year)
            F* is the filename (allowing for spaces and other characters in
the filename).

You could do something like this ..

my @temparr = ();
my $size = 0;
my $filename = "";
foreach $line (@array) {
  @temparr = split(/\s+/,$line,5);
  $size = $temparr[0];
  $filename = $temparr[4];
  print "File ($filename) is of size: $size\n";
}

You could reduce the code much smaller.  Eg.
  my $i,$j,$k;
  foreach $i (@array) {
    ($i,$j,$j,$j,$k) = split($i,5);
    print "File ($k) is of size: $i\n";
  }

.. Or read from standard input instead ..
  my $i,$j,$k;
  while (<>) {
    ($i,$j,$j,$j,$k) = split(5);
    print "File ($k) is of size: $i\n";
  }

If you ONLY want the number ..
  foreach my $i (@array) {
    $i = shift(split($i,5));  # $i contains the file size
  }
If you ONLY want the file name ..
  foreach my $i (@array) {
    $i = pop(split($i,5));  # $i contains the file name
  }
If you ONLY want the Month ..
  foreach my $i (@array) {
    $i = split($i,5)[1];  # $i contains the month
  }

.. but I'd recommend setting out code so it's readable and maintainable
(especially when you're learning).
The aim is not to win at Perl Golf.

HTH.
Brian.