Print lines at particular speed (line/sec)

cat-lps.pl

#!/usr/bin/env perl
#
# Cat file to terminal at particular speed of lines per second
# https://superuser.com/a/526249
#
# Usage: cat-lps.pl [lps] [file]...
#

use warnings;
use strict;
use Time::HiRes qw(time);

# auto flush on every output write; so the content will be complete lines
# when the output is redirected to a file.
$| = 1;

my $lps = 300; # default line/second
$lps = shift @ARGV if @ARGV && $ARGV[0] =~ /^(\d+)$/;

my $sleepPerLine = 1.0 / $lps;
my $start = time;

print &&
    select undef, undef, undef, ($start + $sleepPerLine * $. - Time::HiRes::time)
    while <>