#!/usr/bin/env php
<?php
/**
 * Usage:
 * php aggr.php < 資材ログ.csv > out.csv
 * nkf -Ws -Lw out.csv > 資材ログ.csv
 */

$src = 'php://filter/read=convert.iconv.cp932%2Futf-8/resource=php://stdin';
$file = new SplFileObject($src);
$file->setFlags(SplFileObject::DROP_NEW_LINE);
$lines = [];
foreach ($file as $line) {
    $date = explode(' ', $line, 2)[0];
    $lines[$date] = $line . "\n";
}
file_put_contents('php://stdout', $lines);