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<?php |
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|
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namespace FileUtil; |
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|
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use FileUtil\FileExistsUsingExec; |
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|
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/** |
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* A fileExist function free of deception |
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* |
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* @package FileUtil |
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* @author Bjørn Rosell <[email protected]> |
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*/ |
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class FileExists |
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{ |
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|
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private static $lastWarning; |
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|
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/** |
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* A warning handler that registers that a warning has occured and suppresses it. |
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* |
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* The function is a callback used with "set_error_handler". |
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* It is declared public because it needs to be accessible from the point where the warning is triggered. |
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* |
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* @param integer $errno |
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* @param string $errstr |
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* @param string $errfile |
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* @param integer $errline |
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* |
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* @return void |
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*/ |
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public static function warningHandler($errno, $errstr, $errfile, $errline) |
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{ |
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self::$lastWarning = [$errstr, $errno]; |
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|
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// Suppress the warning by returning void |
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return; |
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} |
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|
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/** |
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* A well behaved replacement for file_exist that throws upon failure rather than emitting a warning. |
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* |
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* @throws \Exception Throws an exception in case file_exists emits a warning |
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* @return boolean True if file exists. False if it doesn't. |
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*/ |
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public static function fileExists($path) |
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{ |
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// There is a challenges here: |
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// We want to suppress warnings, but at the same time we want to know that it happened. |
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// We achieve this by registering an error handler |
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set_error_handler( |
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array('FileUtil\FileExists', "warningHandler"), |
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E_WARNING | E_USER_WARNING | E_NOTICE | E_USER_NOTICE |
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); |
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self::$lastWarning = null; |
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$found = @file_exists($path); |
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|
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// restore previous error handler immediately |
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restore_error_handler(); |
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|
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// If file_exists returns true, we can rely on there being a file there |
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if ($found) { |
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return true; |
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} |
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|
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// file_exists returned false. |
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// this result is only trustworthy if no warning was emitted. |
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if (is_null(self::$lastWarning)) { |
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return false; |
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} |
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|
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list($errstr, $errno) = self::$lastWarning; |
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throw new \Exception($errstr, $errno); |
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} |
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|
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/** |
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* A fileExist doing the best it can. |
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* |
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* @throws \Exception If it cannot be determined if the file exists |
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* @return boolean|null True if file exists. False if it doesn't. |
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*/ |
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public static function fileExistsTryHarder($path) |
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{ |
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try { |
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$result = self::fileExists($path); |
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} catch (\Exception $e) { |
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try { |
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$result = FileExistsUsingExec::fileExists($path); |
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} catch (\Exception $e) { |
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throw new \Exception('Cannot determine if file exists or not'); |
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} catch (\Throwable $e) { |
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throw new \Exception('Cannot determine if file exists or not'); |
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} |
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} |
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return $result; |
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} |
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} |
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|
