#!/usr/bin/env perl

use strict;
use warnings;

use Tie::File;

my $DEBUG_FILE = 'pm_11134904_log_progress.log';
tie my(@DEBUG_RECORDS), 'Tie::File', $DEBUG_FILE
    or die "Can't tie $DEBUG_FILE: $!";

debug("$0 started.");

for my $step ('A' .. 'C') {
    debug("Start step $step");

    if ($step eq 'B') {
        my @paths = 1 .. 5;
        my $overwrite_last = 0;

        for my $path (@paths) {
            sleep 1;
            my $progress = 100 * $path / @paths;
            my $msg = "Processing step $step Progress: $progress%";
            debug($msg, $overwrite_last++);
            show_log_to_date();
        }
    }
    else {
        debug("Processing step $step ...");
    }

    debug("End step $step");
}

debug("$0 completed.");

untie @DEBUG_RECORDS;

show_log_to_date();

sub debug {
    my ($msg, $overwrite_last) = @_;

    my $log_entry = join ' ', "".localtime, $msg;
    pop @DEBUG_RECORDS if $overwrite_last;
    push @DEBUG_RECORDS, $log_entry;

    return;
}

sub show_log_to_date {
    print '-' x 40, "\n";
    system cat => $DEBUG_FILE;
}

##</code><code>##

$ ./pm_11134904_log_progress.pl
----------------------------------------
Sun Jul 11 10:20:39 2021 ./pm_11134904_log_progress.pl started.
Sun Jul 11 10:20:39 2021 Start step A
Sun Jul 11 10:20:39 2021 Processing step A ...
Sun Jul 11 10:20:39 2021 End step A
Sun Jul 11 10:20:39 2021 Start step B
Sun Jul 11 10:20:40 2021 Processing step B Progress: 20%
----------------------------------------
Sun Jul 11 10:20:39 2021 ./pm_11134904_log_progress.pl started.
Sun Jul 11 10:20:39 2021 Start step A
Sun Jul 11 10:20:39 2021 Processing step A ...
Sun Jul 11 10:20:39 2021 End step A
Sun Jul 11 10:20:39 2021 Start step B
Sun Jul 11 10:20:41 2021 Processing step B Progress: 40%
----------------------------------------
Sun Jul 11 10:20:39 2021 ./pm_11134904_log_progress.pl started.
Sun Jul 11 10:20:39 2021 Start step A
Sun Jul 11 10:20:39 2021 Processing step A ...
Sun Jul 11 10:20:39 2021 End step A
Sun Jul 11 10:20:39 2021 Start step B
Sun Jul 11 10:20:42 2021 Processing step B Progress: 60%
----------------------------------------
Sun Jul 11 10:20:39 2021 ./pm_11134904_log_progress.pl started.
Sun Jul 11 10:20:39 2021 Start step A
Sun Jul 11 10:20:39 2021 Processing step A ...
Sun Jul 11 10:20:39 2021 End step A
Sun Jul 11 10:20:39 2021 Start step B
Sun Jul 11 10:20:43 2021 Processing step B Progress: 80%
----------------------------------------
Sun Jul 11 10:20:39 2021 ./pm_11134904_log_progress.pl started.
Sun Jul 11 10:20:39 2021 Start step A
Sun Jul 11 10:20:39 2021 Processing step A ...
Sun Jul 11 10:20:39 2021 End step A
Sun Jul 11 10:20:39 2021 Start step B
Sun Jul 11 10:20:44 2021 Processing step B Progress: 100%
----------------------------------------
Sun Jul 11 10:20:39 2021 ./pm_11134904_log_progress.pl started.
Sun Jul 11 10:20:39 2021 Start step A
Sun Jul 11 10:20:39 2021 Processing step A ...
Sun Jul 11 10:20:39 2021 End step A
Sun Jul 11 10:20:39 2021 Start step B
Sun Jul 11 10:20:44 2021 Processing step B Progress: 100%
Sun Jul 11 10:20:44 2021 End step B
Sun Jul 11 10:20:44 2021 Start step C
Sun Jul 11 10:20:44 2021 Processing step C ...
Sun Jul 11 10:20:44 2021 End step C
Sun Jul 11 10:20:44 2021 ./pm_11134904_log_progress.pl completed.