How to solve php png garbled problem

Usefileperms()togetfilepermissionsasanintegerandformatitusingsprintf('%o')todisplayUnix-stylepermissionslike0644.Forpracticalaccesschecks,useis_readable(),is_writable(),oris_executable()whichreturntrueifthescriptcanread,write,orexecutethefile.Thesefu

Singleton pattern ensures that a class has only one instance and provides a global access point for scenarios where a single object coordinates the operation of the system, such as database connections or configuration management. 2. Its basic structure includes: private static attribute storage instances, private constructors prevent external creation, private cloning methods prevent copying, and public static methods (such as getInstance()) for obtaining instances. 3. Get a unique instance in PHP by calling getInstance() method, and returns the same object reference no matter how many times it is called. 4. Under the standard PHP request model, thread safety is not necessary to be considered, but synchronization issues need to be paid attention to in long run or multi-threaded environments, and PHP itself does not support native lock mechanism. 5. Although singletons are useful,

Use $argv and $argc to get PHP command line parameters. $argc is the number of parameters and $argv is the parameter array. For example, in phpsscript.phphelloworld, $argv=['script.php','hello','world']; use $argv[1] and other to access specific parameters; use getopt() to handle short options (-f) and long options (--file) in complex scenarios.

Answer: PHP's empty merge operator (??) is used to check whether a variable or array key exists and is not null. If it is true, it returns its value, otherwise it returns the default value. It avoids the use of lengthy isset() checks, is suitable for handling undefined variables and array keys, such as $username=$userInput??'guest', and supports chain calls, such as $theme=$userTheme??$defaultTheme??'dark', which is especially suitable for form, configuration, and user input processing, but only excludes null values, empty strings, 0 or false are considered valid values ​​to return.

Use $_GET to get URL parameters, such as ?name=John&age=25; check existence through isset or empty merge operators, and filter and verify data with filter_input to ensure security.

UsetheZipArchiveclasstocreateaZIPfileinPHPbyinstantiatingtheobject,openingthearchivewithopen(),addingfilesviaaddFile()oraddFromString(),andclosingitwithclose()tosave;alwayscheckopen()returnvalueandensurewritepermissions.

Use the json_encode() function to convert PHP arrays or objects into JSON strings. For example, the associative array ["name"=>"John","age"=>30,"city"=>"NewYork"] outputs {"name":"John","age":30,"city":"NewYork&

htmlspecialchars only escapes key HTML metacharacters such as &"', which is suitable for conventional safe output; htmlentities convert all mappable characters (such as éñ©) into HTML entities, which is suitable for handling non-ASCII text and highly compatibility scenarios.