What is php custom error log? Detailed explanation of error log example code

If the defined error log needs to be processed in a timely manner in the project, then the output method of the custom error log needs to be modified (log writing, emailing, text messaging)

1. register_shutdown_function(array('phperror','shutdown_function')); //Define the function to be executed after the PHP program is executed.

The function can implement the function to be executed after the program execution is completed. Its function is Follow-up operations upon completion of program execution can be implemented. There may be an execution timeout or forced shutdown when the program is running, but the default prompt in this case is very unfriendly. If you use the register_shutdown_function() function to catch exceptions, you can provide a more friendly error display method. At the same time, Follow-up operations of some functions can be implemented, such as temporary data cleaning after completion of execution, including temporary files, etc.

You can understand the calling conditions like this:

1. When the page is forced to stop by the user
2. When the program code runs out of time
3. When When the PHP code execution is completed, there are exceptions, errors, and warnings in the code execution

2. set_error_handler(array('phperror','error_handler')); //Set a user-defined error handling function

Set the user-defined error handler through the set_error_handler() function, and then trigger the error (through trigger_error()):

3. set_exception_handler(array('phperror','appException')); // Custom exception handling

Before writing logs, we ask ourselves: Why do we sometimes need to record custom logs? Instead of using the system's default logging method?

1. The team needs a log in a unified format for easy management

2. A large number of useless error logs occupy hard disk space, and only meaningful logs need to be recorded.

Then, practice it.

1. Open your php.ini

2. Turn on logging and change

log_errors = Off

to

log_errors = On

3. Save php.ini Exit and restart the web server

4. Add the following code at the front of your code

<?php
//错误处理函数
function myErrorHandler($errno, $errstr, $errfile, $errline)
{
    $log_file = "./php_%s_log_".date("Ymd").".log";//定义日志文件存放目录和文件名
    $template = &#39;&#39;;
    switch ($errno) {
    case E_USER_ERROR:
        $template .= "用户ERROR级错误，必须修复 错误编号[$errno] $errstr ";
        $template .= "错误位置 文件$errfile,第 $errline 行\n";
        $log_file = sprintf($log_file,&#39;error&#39;);
        exit(1);//系统退出
        break;
    case E_USER_WARNING:
        $template .= "用户WARNING级错误，建议修复 错误编号[$errno] $errstr ";
        $template .= "错误位置 文件$errfile,第 $errline 行\n";
        $log_file = sprintf($log_file,&#39;warning&#39;);
        break;
    case E_USER_NOTICE:
        $template .= "用户NOTICE级错误，不影响系统，可不修复 错误编号[$errno] $errstr ";
        $template .= "错误位置 文件$errfile,第 $errline 行\n";
    $log_file = sprintf($log_file,&#39;notice&#39;);
        break;
    default:
        $template .= "未知错误类型: 错误编号[$errno] $errstr  ";
        $template .= "错误位置 文件$errfile,第 $errline 行\n";
        $log_file = sprintf($log_file,&#39;unknown&#39;);
        break;
    }
    file_put_contents($log_file,$template,FILE_APPEND);
    return true;
}
$error_handler = set_error_handler("myErrorHandler");//开启自定义错误日志

5. Try writing an error code after the previous code

echo 1/0;

Check if there is an extra log file under the path you defined? :)

Note: The following levels of errors cannot be handled by user-defined functions: E_ERROR, E_PARSE, E_CORE_ERROR, E_CORE_WARNING, E_COMPILE_ERROR, E_COMPILE_WARNING, and most E_STRICT generated in the file where the set_error_handler() function is called. .

But when you turn on the error logging system (log_error = on in php.ini) and specify the system log file (also error_log=path name in php.ini), and error_reporting is turned on all , the above errors will be recorded in the file you define as a system error log.

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