wp-optimize / vendor / rosell-dk / webp-convert / src / Helpers / FileExists.php

FileExists.php in WP-Optimize – Cache, Compress images, Minify & Clean database to boost page speed & performance 3.2.3, at vendor/rosell-dk/webp-convert/src/Helpers/FileExists.php

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1	<?php
2
3	namespace WebPConvert\Helpers;
4
5	use ExecWithFallback\ExecWithFallback;
6
7	/**
8	* A fileExist function free of deception
9	*
10	* @package WebPConvert
11	* @author Bjørn Rosell <[email protected]>
12	* @since Class available since Release 2.3.0
13	*/
14	class FileExists
15	{
16
17	private static $lastWarning;
18
19	/**
20	* A warning handler that registers that a warning has occured and suppresses it.
21	*
22	* The function is a callback used with "set_error_handler".
23	* It is declared public because it needs to be accessible from the point where the warning is triggered.
24	*
25	* @param integer $errno
26	* @param string $errstr
27	* @param string $errfile
28	* @param integer $errline
29	*
30	* @return void
31	*/
32	public static function warningHandler($errno, $errstr, $errfile, $errline)
33	{
34	self::$lastWarning = [$errstr, $errno];
35
36	// Suppress the warning by returning void
37	return;
38	}
39
40	/**
41	* A well behaved replacement for file_exist that throws upon failure rather than emmitting a warning.
42	*
43	* @throws \Exception If file_exists threw a warning
44	* @return boolean\|null True if file exists. False if it doesn't.
45	*/
46	public static function honestFileExists($path)
47	{
48	// There is a challenges here:
49	// We want to suppress warnings, but at the same time we want to know that it happened.
50	// We achieve this by registering an error handler
51	set_error_handler(
52	array('WebPConvert\Helpers\FileExists', "warningHandler"),
53	E_WARNING \| E_USER_WARNING \| E_NOTICE \| E_USER_NOTICE
54	);
55	self::$lastWarning = null;
56	$found = @file_exists($path);
57
58	// restore previous error handler immediately
59	restore_error_handler();
60
61	// If file_exists returns true, we can rely on there being a file there
62	if ($found) {
63	return true;
64	}
65
66	// file_exists returned false.
67	// this result is only trustworthy if no warning was emitted.
68	if (is_null(self::$lastWarning)) {
69	return false;
70	}
71
72	list($errstr, $errno) = self::$lastWarning;
73	throw new \Exception($errstr, $errno);
74	}
75
76	/**
77	* A fileExist based on an exec call.
78	*
79	* @throws \Exception If exec cannot be called
80	* @return boolean\|null True if file exists. False if it doesn't.
81	*/
82	public static function fileExistsUsingExec($path)
83	{
84	if (!ExecWithFallback::anyAvailable()) {
85	throw new \Exception(
86	'cannot determine if file exists using exec() or similar - the function is unavailable'
87	);
88	}
89
90	// Lets try to find out by executing "ls path/to/cwebp"
91	ExecWithFallback::exec('ls ' . $path, $output, $returnCode);
92	if (($returnCode == 0) && (isset($output[0]))) {
93	return true;
94	}
95
96	// We assume that "ls" command is general available!
97	// As that failed, we can conclude the file does not exist.
98	return false;
99	}
100
101	/**
102	* A fileExist doing the best it can.
103	*
104	* @throws \Exception If it cannot be determined if the file exists
105	* @return boolean\|null True if file exists. False if it doesn't.
106	*/
107	public static function fileExistsTryHarder($path)
108	{
109	try {
110	$result = self::honestFileExists($path);
111	} catch (\Exception $e) {
112	try {
113	$result = self::fileExistsUsingExec($path);
114	} catch (\Exception $e) {
115	throw new \Exception('Cannot determine if file exists or not');
116	} catch (\Throwable $e) {
117	throw new \Exception('Cannot determine if file exists or not');
118	}
119	}
120	return $result;
121	}
122	}
123