in reply to A whirleygig for a progress indicator for scripts

In the spirit of TMTOWTDI, I thought that using tie might be interesting.

##### Whirley package
package Whirley;
use strict;
my @whirlies = qw!. o 0 O 0 o!;
my $current  = -1;

sub TIESCALAR {
  my $type  = shift;
  my $class = ref $type || $type;
  my $self = {};
  bless $self, $class;
}

sub FETCH {
  my $self = shift;
  my $backspace = $current < 0 ? '' : "\b"; # don't backspace on first
+ go 'round
  $current = 0 if (++$current == @whirlies);
  return $backspace . $whirlies[$current];
}

##### Main package
package Main;
use strict;
$|++;

my $whirley;
tie $whirley, 'Whirley';

print "Please wait: ";
while (1) {
  print $whirley;
  sleep 1;
}

[download]

Cheers,
Shendal

Replies are listed 'Best First'.
Re: Re: A whirleygig for a progress indicator for scripts
by rob_au (Abbot) on Dec 18, 2002 at 12:53 UTC
    Using the Tie::Cycle module, this can be simplified further ...

    use Tie::Cycle;

tie my $whirley, 'Tie::Cycle', [ qw( . o 0 O 0 o ) ];

#   And now for the demonstration ...

++$|;

while (1) {
    print $whirley, "\b";
    sleep 1;
}

    [download]

     

    perl -le 'print+unpack("N",pack("B32","00000000000000000000001000000000"))'

[reply]
[d/l]
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In Section Cool Uses for Perl