xml_parser_free

(PHP 4, PHP 5, PHP 7, PHP 8)

xml_parser_free — 释放指定的 XML 解析器

描述

xml_parser_free(resource $parser): bool

parser: 指向要释放的 XML 解析器的指针。

如果 parser 参数没有指向一个合法的解析器，该函数将返回 false，否则将释放指定的解析器并返回 true。

add a note

User Contributed Notes 3 notes

down

-1

nidzho ¶

5 years ago


Unset the parser after calling xml_parser_free() to prevent memory leaks:

<?php
xml_parser_free($parser);
unset($parser);
?>

down

-2

dio at edu dot uni-klu dot ac dot at ¶

16 years ago


If you try to free an XML parser while it is still parsing, strange things will happen - your script will "hang" and no output will be sent to the browser. Consider this pseudo-code example:

-------

...
if (!xml_parse($parser)) echo 'XML error';

xml_parser_free($parser);

...

function SomeCallbackWhichWasSetBefore(...)
{
global $parser;

...

if (some_error_happened) xml_parser_free($parser);  //problem!

...

}

------

It would be logical that xml_parse would return false if the parser was freed while parsing, right? Wrong! Instead, everything hangs and no output will be sent out (no matter whether output buffering is on or not). It took me more than an hour to figure out why: you cannot free a parser handle that is currently parsing. A simple solution:

-------

$xml_error = false;
if (!xml_parse($parser))
echo 'XML error (directly from parser)';
else if ($xml_error)
echo 'XML error (from some callback function);

xml_parser_free($parser);

...

function SomeCallbackWhichWasSetBefore(...)
{
global $parser;
global $xml_error;

if ($xml_error)
return;

...

if (some_error_occured)
{
$xml_error = false;
return;
}

...

}

-------

If you use this solution you will have to check for $xml_error in every callback function. Essentially what you're doing is that, in case you want to stop parsing because of an error, you continue until xml_parse() is finished (without actually doing anything) and then free the parser and act on the error.

Of course the underlying problem is that you cannot stop a parser while it is parsing. There should be some function like xml_throw_error() or xml_parser_stop() or whatever, but unfortunately there isn't.

down

-3

php dot net at gwprogramming dot com (George Webb) ¶

18 years ago


I found that with PHP 4.3.4RC1, if you don't call xml_parser_free() before your script ends, some sort of ugliness occurs with the webserver; i.e. the HTTP connection is closed.  (The apache error_log says "exit signal Segmentation fault (11)".)

Usually PHP tends to clean up connections you don't explicitly close (e.g. database connections), but in this case apparently it doesn't.

Some web browsers (MSIE for one) do not actually show this problem, so you may not actually notice it.  Opera 7.11 does show it, which is how I discovered it.

So don't forget to call xml_parser_free() ... always!

add a note

官方地址：https://www.php.net/manual/en/function.xml-parser-free.php

有任何技术问题请点击这里网站运营推广招聘

IT PHP 编程语言 Linux 开发编程科技 Elasticsearch HTML/CSS/XML 网络 JAVA NoSQL 数据库面试 C/C++ Golang Git 算法操作系统正则表达式 Redis 互联网 MySql JavaScript 运维软件国际架构设计 Mac OS TCP/IP Excel Vim Windows Socket Oracle VR MongoDB Python 运营 MemCache 商业硬件电子娱乐设计 nginx 摄影游戏 WordPress HTTP 团建数码电器

php7 安装fileinfo扩展 preg_split — 通过一个正则表达式分隔字符串 php位值,解决 PHP 中 usort 在值相同时改变原始位置的问题 [PHP] inet_pton/inet_ntop IP地址转换函数 array_multisort() 多字段排序 PHPMailer设置utf8 PHPMailer字符集CharSet ADORecordSet对象 PHP 8.1 [鸟哥]PHP_INT_MIN 和 -9223372036854775808 adodb手册 opcache预加载 Composer的Packagist资源 mysql面试题 php中几种注释规范 PHP7 mcrypt替代方案 Packagist / Composer 中国全量镜像 php扩展开发 [原创]诡异的php-fpm超时问题 laravel框架查看sql语句方式支持php7的性能采集扩展

略微加速

PHP官方手册 - 互联网笔记

xml_parser_free

描述

User Contributed Notes 3 notes