Tip:
$opt->{'encoding'} ? $opt->{'encoding'} : 'utf-8'
is more idiomatically/simply written as
$opt->{encoding} || 'utf-8'
Tip:
if ( length($line) > 0 || $opt->{'empty'} && $opt->{'empty'} eq 'fill'
+ ) {
$final_line = $prefix . $line . $suffix;
}
elsif ( $opt->{'empty'} && $opt->{'empty'} eq 'blank' ) {
$final_line = '';
}
elsif ( $opt->{'empty'} && $opt->{'empty'} eq 'undefined' ) {
$final_line = undef;
}
else {
next;
}
could be simplified to
my $empty = $opt->{empty} || '';
...
if ( length($line) || $empty eq 'fill' ) {
$final_line = $prefix . $line . $suffix;
}
elsif ( $empty eq 'blank' ) {
$final_line = '';
}
elsif ( $empty eq 'undefined' ) {
$final_line = undef;
}
else {
next;
}
But I'd personally setup some variables beforehand.
my $empty = $opt->{empty} || '';
my $trim_empty = !$empty;
my $keep_empty = $empty eq 'fill';
my $empty_replacement = $empty eq 'blank' ? '' : undef;
...
if ( length($line) || $keep_empty ) {
push @array, $prefix . $line . $suffix;
}
elsif ( !$trim_empty ) {
push @array, $empty_replacement;
}