Detailed introduction to handling exception errors in PHP

1. Error reporting level error_reporting()

error_reporting(int $level);

PHP 5.4 and above E_ALL includes E_STRICT.

PHP Manual All error levels.

Example:

<?php

// 关闭所有PHP错误报告
error_reporting(0);

// Report simple running errors
error_reporting(E_ERROR | E_WARNING | E_PARSE);

// 报告 E_NOTICE也挺好 (报告未初始化的变量
// 或者捕获变量名的错误拼写)
error_reporting(E_ERROR | E_WARNING | E_PARSE | E_NOTICE);

// 除了 E_NOTICE，报告其他所有错误
error_reporting(E_ALL ^ E_NOTICE);

// 报告所有 PHP 错误 (参见 changelog)
error_reporting(E_ALL);

// 报告所有 PHP 错误
error_reporting(-1);

// 和 error_reporting(E_ALL); 一样
ini_set(&#39;error_reporting&#39;, E_ALL);

?>

2. Error handling function set_error_handler()

set_error_handler(function (int $errno, string $errstr, string $errfile, int $errline) {
    // ...
}, $error_types = E_ALL)

specified by the above $error_types The error type will be intercepted by the error handling function (unless the function returns false)

When an error occurs in a statement prefixed with @, the $errno value is 0

The script will continue to execute after the processing function ends (so you need to actively call die() if necessary)

Example:

function handleError($level, $message, $file = '', $line = 0)
{
    if (error_reporting() & $level) {
        throw new ErrorException($message, 0, $level, $file, $line);
    }
    return false;
}

Convert Error Exception

Note: Uncatchable Error

The following level errors cannot be user-defined Function to process:

E_ERROR

<strong>##E_PARSE<span style="font-size: 14px;"></span></strong>

<strong>E_CORE_ERROR<span style="font-size: 14px;"></span></strong>

##E_CORE_WARNING<strong><span style="font-size: 14px;"></span></strong> <strong><span style="font-size: 14px;"></span></strong>

##E_COMPILE_ERROR<strong><span style="font-size: 14px;"></span></strong>

##E_COMPILE_WARNING

<strong><span style="font-size: 14px;"></span></strong>Most E_STRICT generated in the file where the

set_error_handler()

function is called. These uncaught errors can be handled in register_shutdown_function() (but the script will still end)

3. 异常处理函数 set_exception_handler

// < PHP 7
set_exception_handler(&#39;handleException&#39;)


// < PHP 7
handleException(Exception $ex)
{
    echo "Uncaught exception: " , $ex->getMessage(), "\n";
}


// >= PHP 7
handleException(Throwable $ex)
{
    echo "Uncaught exception: " , $ex->getMessage(), "\n";
}

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在用户自定义异常处理函数内部, 可根据情况做一下处理:

日志记录错误

web 渲染错误页面

console 渲染错误提示

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4. PHP 中止时执行函数 

<span style="font-size: 14px;">register_shutdown_function</span>

register_shutdown_function(function () {

}, $para1, $param2, ...)

在用户自定义脚本中止处理函数内部, 可根据情况做一下处理:

判断是否因严重错误而结束脚本(无法被 set_error_handler 捕获的错误中止脚本)

register_shutdown_function('handleShutdown')

function handleShutdown()
{
if (! is_null($error = error_get_last()) && isFatal($error['type'])) {
      // handleException() 函数同时处理 set_exception_handler
      handleException(new \ErrorException(
        $error['message'], $error['type'], 0, $error['file'], $error['line'],
      ));
  }
}

function isFatal($type)
{
  return in_array($type, [E_COMPILE_ERROR, E_CORE_ERROR, E_ERROR, E_PARSE]);
}

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以下错误无法被 set_error_handler 捕获

E_ERROR

E_PARSE

E_CORE_ERROR

E_CORE_WARNING

E_COMPILE_ERROR

E_COMPILE_WARNING

若因为错误而结束脚本, 若是严重错误则可将其转为 异常类, 并由异常处理函数统一处理.

Note:

多次调用 register_shutdown_function 时不会互相覆盖, 而是会按照注册顺序被依次调用.

除非在某个注册的方法内部调用 exit()

Note:

进程被信号 SIGTERM 或 SIGKILL 杀死时中止函数不会被调用. 可通过 pcntl_signal 捕获信号, 再在其中调用 exit() 来进行正常中止。

以上就是关于错误异常的处理，如有错误请指出。不胜感激！

更多相关问题请访问PHP中文网：PHP视频教程

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