#!/usr/bin/perl
use strict;
use warnings;
use feature 'say';

sub myChmop {
    my ($str) = @_;
    chomp $str;
    return $str;
}

sub myCrRemove {
    my ($str) = @_;
    $str =~ s/\r|\n//g;
    return $str;
}

my $str = "abcd\r\n";
my $chompReturn = myChmop($str);
say "[$chompReturn]";

my $crRemoveReturn = myCrRemove($str);
say "[$crRemoveReturn]";

__END__

$ perl test.pl
]abcd
[abcd]