http://www.perlmonks.org?node_id=396857


in reply to Progress Bar

(Updated: Something bad happened to the code portion during cut-and-paste to the site. This is now fixed.)

Here's a quick bit of code that provides a simple, object-oriented way to draw progress bars. To use it, just create a progress bar like so:

my $bar = ProgressBar->new( width => 40 );
(Here, our bar will be 40 characters wide.) Then, to draw the bar, just pass in the current count of completed tasks and the total number of tasks:
$bar->draw( 3, 10 );
So, in the above example, we have completed 3 of 10 tasks and the following would be drawn:
============ 30%
A couple of points:

Here's the code:

#!/usr/bin/perl -w { # TGM 2004-10-05 # Progress bar code package ProgressBar; use Class::Struct width => '$', portion => '$', max_val => '$'; use List::Util qw( min ); sub draw { local $| = 1; my ($self, $x, $max_val) = @_; $max_val ||= $self->max_val; my $old_portion = $self->portion || 0; my $new_portion = int( $self->width * $x / $max_val + 0.5 ); print "\b" x ( 6 + $self->width - min( $new_portion, $old_portion ) ) if defined $self->portion; print "=" x ( $new_portion - $old_portion ), " " x ( $self->width - $new_portion ), sprintf " %3d%% ", int( 100 * $x / $max_val + 0.5 ); $self->portion( $new_portion ); } 1; } # DEMO my $pb = ProgressBar->new( width => 40, max_val => 10 ); # show progress 0 to 100% and then back down to 0% again do { $pb->draw( $_ ) ; sleep 1 } for 0 .. 10; do { $pb->draw( 9 - $_ ); sleep 1 } for 0 .. 9; print "\n";
Hope this helps.

Cheers,
Tom