Redirects things from a CSV of old paths

nginx-server.conf

server {
	server_name example.com www.example.com;
	listen 80;
	
	location / {
		fastcgi_pass    unix:/var/run/php/php7.4-fpm.sock;
		include         fastcgi_params;
		fastcgi_param   SERVER_NAME $host;
		fastcgi_param   SCRIPT_FILENAME /var/www/path/to/router.php;
	}
}

redirect.php

<?php
// Adjust constants as desired.
// CSV must have old URL in first column, new URL in second column.
const CSV_PATH = __DIR__ . "/redirects.csv";
const STATUS_CODE = 303;
const REDIRECT_IF_NO_MATCH = "http://example.com";

$requestUri = $_SERVER["REQUEST_URI"] ?? $argv[1] ?? "/";
$requestUri = parse_url($requestUri, PHP_URL_PATH);
$csv = fopen(CSV_PATH, "r");

while(!feof($csv)) {
	list($from, $to) = fgetcsv($csv);
	$fromPath = parse_url($from, PHP_URL_PATH);

	if($requestUri === $fromPath) {
		header("Location: $to", true, STATUS_CODE);
		exit;
	}
}

header("Location: " . REDIRECT_IF_NO_MATCH, true, STATUS_CODE);
exit;