--- /dev/null
+<?php
+
+/*
+ * This file is part of Psy Shell.
+ *
+ * (c) 2012-2017 Justin Hileman
+ *
+ * For the full copyright and license information, please view the LICENSE
+ * file that was distributed with this source code.
+ */
+
+namespace Psy\Readline;
+
+/**
+ * A Readline interface implementation for GNU Readline.
+ *
+ * This is by far the coolest way to do it, but it doesn't work with new PHP.
+ *
+ * Oh well.
+ */
+class GNUReadline implements Readline
+{
+ /** @var string|false */
+ protected $historyFile;
+ /** @var int */
+ protected $historySize;
+ /** @var bool */
+ protected $eraseDups;
+
+ /**
+ * GNU Readline is supported iff `readline_list_history` is defined. PHP
+ * decided it would be awesome to swap out GNU Readline for Libedit, but
+ * they ended up shipping an incomplete implementation. So we've got this.
+ *
+ * @return bool
+ */
+ public static function isSupported()
+ {
+ return function_exists('readline_list_history');
+ }
+
+ /**
+ * GNU Readline constructor.
+ *
+ * @param string|false $historyFile
+ * @param int $historySize
+ * @param bool $eraseDups
+ */
+ public function __construct($historyFile = null, $historySize = 0, $eraseDups = false)
+ {
+ $this->historyFile = ($historyFile !== null) ? $historyFile : false;
+ $this->historySize = $historySize;
+ $this->eraseDups = $eraseDups;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function addHistory($line)
+ {
+ if ($res = readline_add_history($line)) {
+ $this->writeHistory();
+ }
+
+ return $res;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function clearHistory()
+ {
+ if ($res = readline_clear_history()) {
+ $this->writeHistory();
+ }
+
+ return $res;
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function listHistory()
+ {
+ return readline_list_history();
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function readHistory()
+ {
+ // Workaround PHP bug #69054
+ //
+ // If open_basedir is set, readline_read_history() segfaults. This was fixed in 5.6.7:
+ //
+ // https://github.com/php/php-src/blob/423a057023ef3c00d2ffc16a6b43ba01d0f71796/NEWS#L19-L21
+ //
+ if (version_compare(PHP_VERSION, '5.6.7', '>=') || !ini_get('open_basedir')) {
+ readline_read_history();
+ }
+ readline_clear_history();
+
+ return readline_read_history($this->historyFile);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function readline($prompt = null)
+ {
+ return readline($prompt);
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function redisplay()
+ {
+ readline_redisplay();
+ }
+
+ /**
+ * {@inheritdoc}
+ */
+ public function writeHistory()
+ {
+ // We have to write history first, since it is used
+ // by Libedit to list history
+ if ($this->historyFile !== false) {
+ $res = readline_write_history($this->historyFile);
+ } else {
+ $res = true;
+ }
+
+ if (!$res || !$this->eraseDups && !$this->historySize > 0) {
+ return $res;
+ }
+
+ $hist = $this->listHistory();
+ if (!$hist) {
+ return true;
+ }
+
+ if ($this->eraseDups) {
+ // flip-flip technique: removes duplicates, latest entries win.
+ $hist = array_flip(array_flip($hist));
+ // sort on keys to get the order back
+ ksort($hist);
+ }
+
+ if ($this->historySize > 0) {
+ $histsize = count($hist);
+ if ($histsize > $this->historySize) {
+ $hist = array_slice($hist, $histsize - $this->historySize);
+ }
+ }
+
+ readline_clear_history();
+ foreach ($hist as $line) {
+ readline_add_history($line);
+ }
+
+ if ($this->historyFile !== false) {
+ return readline_write_history($this->historyFile);
+ }
+
+ return true;
+ }
+}