#!/usr/bin/env perl

use 5.012;
use warnings;
use autodie;
use Getopt::Long;

# Replace tabs with 4 spaces

my $verbose = 0;
GetOptions(verbose => \$verbose);
die "Usage: $0 [--verbose] input_path output_path" if @ARGV != 2;
map { die "$_ is not a directory, or does not exist\n" unless -d } @ARGV;

my ($input, $output) = @ARGV;

opendir my ($in_dir), $input;
for (sort grep { -f "$input/$_" } readdir $in_dir) {
    say if $verbose;
    open my $in,  '<', "$input/$_";
    open my $out, '>', "$output/$_";
    while (<$in>) {
        s/\t/    /sg;
        print $out $_;
    }
    close $in;
    close $out;
}
closedir $in_dir;