<?php
/*
* This file is part of Psy Shell.
*
* (c) 2012-2020 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 = $eraseDups;
// HHVM errors on this, so HHVM doesn't get a readline_name.
if (!\defined('HHVM_VERSION')) {
\readline_info('readline_name', 'psysh');
}
}
/**
* {@inheritdoc}
*/
public function addHistory($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;
}
}