delay_buffer

#!/usr/bin/env php
<?php

function helpMessage($exit = 0) {
    echo <<<EOT
Delay output by specified number of seconds.

    -t <float> duration in seconds

EOT;
    exit($exit);
}

$args = getopt("ht:", []);
if (isset($args["h"])) {
    helpMessage();
}

if (!isset($args['t'])) {
    helpMessage(1);
}
$delay_s = (float) $args['t'];

ini_set("memory_limit", "-1");
$start = microtime(true);
$buffer = '';
$is_delay_over = false;
while (($bytes = fread(STDIN, 4096)) || !$is_delay_over) {
    $elapsed = microtime(true) - $start;
    if ($elapsed > $delay_s) {
        if ($is_delay_over && $bytes !== false) {
            echo $bytes;
        } else {
            $is_delay_over = true;

            // not sure if this loop is necessary or if I can just `echo $buffer;` ?
            $buffer_piece_index = 0;
            while ($buffer_piece = substr($buffer, $buffer_piece_index, 4096)) {
                $buffer_piece_index += 4096;
                echo $buffer_piece;
            }
            if ($bytes !== false) {
                echo $bytes;
            }
        }
    } else if ($bytes !== false) {
        $buffer .= $bytes;
    }
}