#!/bin/env perl

# Counts the number of lines in each .txt file.

use 5.10.1;
use warnings;
use strict;

use File::Next;

my $start = shift or die;

use IO::Handle;
pipe(FINDER, COUNTER);
COUNTER->autoflush(1);

my $child_pid;
if ($child_pid = fork()) {
    close COUNTER;

    my $total = 0;
    while ( my $file = <FINDER> ) {
        my $n = 0;
        chomp $file;
        open( my $fh, '<', $file ) or die "Can't open $file: $!\n";
        while ( <$fh> ) {
            ++$n;
        }
        close $fh;
        printf "%5d: %s\n", $n, $file;
        $total += $n;
    }
    waitpid $child_pid, 0;
    say "$total lines of text in $start";
}
else {
    die "cannot fork: $!" unless defined $child_pid;
    close FINDER;
    my $iter = File::Next::files( { descend_filter => sub { $_ ne '.git' }, file_filter => sub { /\.txt/ } }, $start );
    while ( my $file = $iter->() ) {
        say COUNTER $file;
    }
    warn "############ Child is done looking #############\n";
    exit 0;
}