php出现空白页面

在使用 PHP 程序的过程中,我们经常会碰到页面出现空白,页面出现空白是因为程序运行过程中遇到问题不能正常执行,而 PHP 环境配置信息又阻止向页面输出 PHP 返回的错误信息,遇到这样的问题不要惊慌,只要打开PHP的报错信息,然后根据错误信息提示就能找到问题的原因,然后逐步解决。

下面介绍如何在程序中设置PHP的报错级别:

我们在程序运行的开始利用 error_reporting()函数设置 PHP 的报错级别并返回当前级别。

error_reporting(report_level)

如果参数 level 未指定,当前报错级别将被返回。下面几项是 level 可能的值:

值 常量 描述

1 E_ERROR Fatal run-time errors. Errors that can not be recovered from. Execution of the script is halted

2 E_WARNING Non-fatal run-time errors. Execution of the script is not halted

4 E_PARSE Compile-time parse errors. Parse errors should only be generated by the parser

8 E_NOTICE Run-time notices. The script found something that might be an error, but could also happen when running a script normally

16 E_CORE_ERROR Fatal errors at PHP startup. This is like an E_ERROR in the PHP core

32 E_CORE_WARNING Non-fatal errors at PHP startup. This is like an E_WARNING in the PHP core

64 E_COMPILE_ERROR Fatal compile-time errors. This is like an E_ERROR generated by the Zend Scripting Engine

128 E_COMPILE_WARNING Non-fatal compile-time errors. This is like an E_WARNING generated by the Zend Scripting Engine

256 E_USER_ERROR Fatal user-generated error. This is like an E_ERROR set by the programmer using the PHP function trigger_error()

512 E_USER_WARNING Non-fatal user-generated warning. This is like an E_WARNING set by the programmer using the PHP function trigger_error()

1024 E_USER_NOTICE User-generated notice. This is like an E_NOTICE set by the programmer using the PHP function trigger_error()

2048 E_STRICT Run-time notices. PHP suggest changes to your code to help interoperability and compatibility of the code

4096 E_RECOVERABLE_ERROR Catchable fatal error. This is like an E_ERROR but can be caught by a user defined handle (see also set_error_handler())

8191 E_ALL All errors and warnings, except level E_STRICT (E_STRICT will be part of E_ALL as of PHP 6.0)

例子

任意数目的以上选项都可以用“或”来连接(用 OR 或 |),这样可以报告所有需要的各级别错误。例如,下面的代码关闭了用户自定义的错误和警告,执行了某些操作,然后恢复到原始的报错级别:

//禁用错误报告

error_reporting(0);

//报告运行时错误

error_reporting(E_ERROR | E_WARNING | E_PARSE);

//报告所有错误

error_reporting(E_ALL);

转载:网络