<?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;
use Psy\Util\Str;
/**
* A Libedit-based Readline implementation.
*
* This is largely the same as the Readline implementation, but it emulates
* support for `readline_list_history` since PHP decided it was a good idea to
* ship a fake Readline implementation that is missing history support.
*/
class Libedit extends GNUReadline
{
private $hasWarnedOwnership = false;
/**
* Let's emulate GNU Readline by manually reading and parsing the history file!
*
* @return bool
*/
public static function isSupported()
{
return \function_exists('readline') && !\function_exists('readline_list_history');
}
/**
* {@inheritdoc}
*/
public function listHistory()
{
$history = \file_get_contents($this->historyFile);
if (!$history) {
return [];
}
// libedit doesn't seem to support non-unix line separators.
$history = \explode("\n", $history);
// shift the history signature, ensure it's valid
if (\array_shift($history) !== '_HiStOrY_V2_') {
return [];
}
// decode the line
$history = \array_map([$this, 'parseHistoryLine'], $history);
// filter empty lines & comments
return \array_values(\array_filter($history));
}
/**
* {@inheritdoc}
*/
public function writeHistory()
{
$res = parent::writeHistory();
// Libedit apparently refuses to save history if the history file is not
// owned by the user, even if it is writable. Warn when this happens.
//
// See https://github.com/bobthecow/psysh/issues/552
if ($res === false && !$this->hasWarnedOwnership) {
if (\is_file($this->historyFile) && \is_writable($this->historyFile)) {
$this->hasWarnedOwnership = true;
$msg = \sprintf('Error writing history file, check file ownership: %s', $this->historyFile);
\trigger_error($msg, E_USER_NOTICE);
}
}
return $res;
}
/**
* From GNUReadline (readline/histfile.c & readline/histexpand.c):
* lines starting with "\0" are comments or timestamps;
* if "\0" is found in an entry,
* everything from it until the next line is a comment.
*
* @param string $line The history line to parse
*
* @return string | null
*/
protected function parseHistoryLine($line)
{
// empty line, comment or timestamp
if (!$line || $line[0] === "\0") {
return;
}
// if "\0" is found in an entry, then
// everything from it until the end of line is a comment.
if (($pos = \strpos($line, "\0")) !== false) {
$line = \substr($line, 0, $pos);
}
return ($line !== '') ? Str::unvis($line) : null;
}
}