Add cron script for removing aged extracted comics

cron/.htaccess

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+order allow,deny
+deny from all

cron/README.md

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+## Scripts intended for use by cron
+
+Scripts in this folder are intended to be run by cron, likely as the user running the web server process.
+
+* __clearextracts.php:__ Used to purge the folder used for extracting comics for viewing by clients. It should be run by the web service owner and takes a single parameter for the number of days to keep extracts before removing them.
+  - "su" to root: `sudo su -`
+  - Run crontab as web server owner: `sudo web -c "crontab -e"`
+  - Add crontab line with frequency and days/age parameter
+    - `15 3 * * * /usr/local/bin/php /var/www/htdocs/comics/cron/clearextracts.php 5 1>/dev/null 2>&1`

cron/clearextracts.php

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+<?php
+
+$projectRoot = dirname(dirname(__FILE__));
+
+require "{$projectRoot}/header.php";
+
+if ( $argc != 2 ) {
+    echo "Invalid number of days to keep\n";
+    exit();
+}
+$daysToKeep = intval($argv[1]);
+
+$ed = $projectRoot . "/" . EXTRACTSDIR;
+$now = time();
+$maxAge = $now - (86400*$daysToKeep);
+
+$it = new RecursiveDirectoryIterator($ed, RecursiveDirectoryIterator::SKIP_DOTS);
+$files = new RecursiveIteratorIterator($it, RecursiveIteratorIterator::CHILD_FIRST);
+$validExtensions = array("cbr","cbz");
+foreach ( $files as $file ) {
+    if ( $file->isDir() && in_array($file->getExtension(), $validExtensions) ) {
+        if ( filemtime($file->getRealPath()) <= $maxAge ) {
+            echo "Found aged extracted comic: {$file->getFilename()}\n";
+            exec("rm -rf \"{$file->getRealPath()}\"", $output, $retval);
+        }
+    }
+}