$ perl -Mstrict -Mwarnings -e '
use Smart::Comments;
for (1 .. 500) { ### Running...         done
    qx{ls -l > /dev/null 2>&1};
}
'

##</code><code>##

#!/usr/bin/env perl

use strict;
use warnings;

my $CMD = q{ls -l > /dev/null};

for ([], [q{}], [q{dummy}], [$CMD, 10], [$CMD], [$CMD, 50]) {
    eval {
        run_with_progress(@$_);
    };
    warn $@ if $@;
}

sub run_with_progress {
    print q{-} x 60, qq{\nStarting ...\n};

    my ($cmd, $skip) = @_;

    die q{Nothing to run!} unless $cmd;
    $skip ||= 25;   # Arbitrary

    my @sails = map { "\b$_" } qw{- \ | /};
    my $sail = 0;

    {
        local $| = 1;

        print q{Running:  };

        for (0 .. 1000) {
            system $cmd and die qq{'$cmd' failed! $? : $!};

            print $sails[$sail++ % @sails] if not $_ % $skip;
        }
    }

    print qq{\b*\nFinished.\n};
}

##</code><code>##

$ pm_text_spinner_ryo.pl
------------------------------------------------------------
Starting ...
Nothing to run! at ./pm_text_spinner_ryo.pl line 20.
------------------------------------------------------------
Starting ...
Nothing to run! at ./pm_text_spinner_ryo.pl line 20.
------------------------------------------------------------
Starting ...
Running:  Can't exec "dummy": No such file or directory at ./pm_text_spinner_ryo.pl line 32.
'dummy' failed! -1 : No such file or directory at ./pm_text_spinner_ryo.pl line 32.
------------------------------------------------------------
Starting ...
Running: *
Finished.
------------------------------------------------------------
Starting ...
Running: *
Finished.
------------------------------------------------------------
Starting ...
Running: *
Finished.

##</code><code>##

sub run_with_progress {
    use Smart::Comments;

    ### Starting ...

    my ($cmd, $skip) = @_;

    die q{Nothing to run!} unless $cmd;
    $skip ||= 25;   # Arbitrary

    my @sails = map { ($_) x $skip } qw{- \ | /};
    my $sail = 0;

    for (0 .. 1000) {   ### Running: $sails[$sail++ % @sails]
        system $cmd and die qq{'$cmd' failed! $? : $!};
    }   

    ### Finished.

    no Smart::Comments;

    return;
}

##</code><code>##

$ pm_text_spinner_sc_spin.pl

### Starting ...
Nothing to run! at ./pm_text_spinner_sc_spin.pl line 22.

### Starting ...
Nothing to run! at ./pm_text_spinner_sc_spin.pl line 22.

### Starting ...
Running: -                         Can't exec "dummy": No such file or directory at ./pm_text_spinner_sc_spin.pl line 29.
'dummy' failed! -1 : No such file or directory at ./pm_text_spinner_sc_spin.pl line 29.

### Starting ...
                                                                     

### Finished.

### Starting ...
                                                                     

### Finished.

### Starting ...
                                                                     

### Finished.

##</code><code>##

sub run_with_progress {
    print q{-} x 60, qq{\nStarting ...\n};

    my ($cmd, $skip) = @_;

    die q{Nothing to run!} unless $cmd;
    $skip ||= 25;   # Arbitrary

    use Term::Spinner;
    my $spinner = Term::Spinner::->new();

    print q{Running: };

    for (0 .. 1000) {
        system $cmd and die qq{'$cmd' failed! $? : $!};

        $spinner->advance() if not $_ % $skip;
    }   

    $spinner->finish();
    print qq{\nFinished.\n};
    undef $spinner;

    return;
}