Table of Contents
PHP uses the xmllint command to process xml and html, xmllintxml
Home Backend Development PHP Tutorial How PHP uses the xmllint command to process xml and html, xmllintxml_PHP tutorial

How PHP uses the xmllint command to process xml and html, xmllintxml_PHP tutorial

Jul 13, 2016 am 10:11 AM
php xml method

PHP uses the xmllint command to process xml and html, xmllintxml

The example in this article describes how PHP uses the xmllint command to process xml and html. Share it with everyone for your reference. The specific analysis is as follows:

xmllint is a very convenient tool for processing and verifying xml and processing html. Under Linux, you can use this command as long as libxml2 is installed. First, let’s take a look at an example of processing HTML using the --html and --xpath parameters:

An example is as follows:

Copy code The code is as follows:
curl http://www.bkjia.com /ip/?q=8.8.8.8 2>/dev/ null |

In the above example, only the content of the text part is obtained by extracting the result (ul#csstb) after querying the ownership of the IP address on 123cha. The result after executing the above script statement is as follows:

[Your query]:8.8.8.8
Main data of this site:
USA> Auxiliary data of this site: Google Public DNS provided:hypo
United States Google’s free Google Public DNS provides: zwstar reference data 1: United States
Reference data two: United States

Let’s take a look at the usage of other main parameters with examples.


1. --format
This parameter is used to format the xml so that it has good readability.
Suppose there is xml (person.xml) with the following content:

Copy code The code is as follows:
ball30 male
After performing the following operations, the output will be in a more readable xml format:

Copy code The code is as follows:
#xmllint --format person.xml


ball
30
male


2. --noblanks
Contrary to --format, sometimes in order to save transmission volume, we want to remove the blanks in xml. In this case, we can use the --noblanks command.
Assume that the content of xml (person.xml) is as follows

Copy code The code is as follows:

ball
30
male

After executing this parameter operation, the output result is:

Copy code The code is as follows:
#xmllint --noblanks person.xml

ball
3. --schema

Use scheam to verify the correctness of xml files (XML Schema is an XML-based DTD replacement) Assume that there are xml files (person.xml) and scheam files (person.xsd). The contents are as follows
person.xml



Copy code
The code is as follows:
ball
30
male


person.xsd


Copy code
The code is as follows:

   
     
     
     
       
         
           
           
         

       

     

     
       
         
           
           
           
         

       

     

   

按如下命令执行后的结果是:

复制代码 代码如下:
#xmllint --schema person.xsd person.xml

   
      ball
      30
      male
   

person.xml validates 
注:默认情况下,验证后会输出验证的文件内容,可以使用 --noout选项去掉此输出,这样我们可以只得到最后的验证结果。

复制代码 代码如下:
#xmllint --noout --schema person.xsd person.xml

person.xml validates 
下面我们改动person.xml,使这份文件age字段和sex都是不符合xsd定义的。
复制代码 代码如下:
#xmllint --noout --schema person.xsd person.xml
person.xml:4: element age: Schemas validity error : Element 'age': 'not age' is not a valid value of the atomic type 'xs:integer'.
person.xml:5: element sex: Schemas validity error : Element 'sex': [facet 'enumeration'] The value 'test' is not an element of the set {'male', 'female'}.
person.xml:5: element sex: Schemas validity error : Element 'sex': 'test' is not a valid value of the local atomic type.
person.xml fails to validate

可以看到xmllint成功的报出了错误!

4、 关于--schema的输出

在讲输出之前先看下面一个场景,假如你想通过php执行xmllint然后拿到返回结果,你的代码通常应该是这个样子valid.php

复制代码 代码如下:
$command = "xmllint --noout --schema person.xsd person.xml";
exec($command, $output, $retval);
//出错时返回值不为0
if ($retval != 0){
    var_dump($output);
}
else{
    echo "yeah!";
}

We keep the errors in person.xml above.

Execute this code and you will find that the output you get is not an error, but array(0) {}, amazing!
Why is this happening?

Because of xmllint --schema, if an error occurs during verification, the error message will not be displayed through the standard output (stdout), but through the standard error (stderr).

The output parameter of exec can only get the content displayed by the standard output (stdout).
Therefore, in order to get the error message, we need to redirect standard error to standard output and modify the code accordingly:

Copy code The code is as follows:
$command = "xmllint --noout --schema person.xsd person.xml 2>$1";

Execute valid.php again and get the error message successfully!

Examples are as follows:
First create an xml document, named po.xml, with the following content:

Copy code The code is as follows:



                                                                                                                                                                    123 Maple Street
                                                                                                                                                                                                                                                                                                   


                                                                                                                                                                                                                                                                                                                                                                                                                                                                         

Hurry, my lawn is going wild!

         
                                                                                                                                                                                                                  Lawnmower
                                             1
                                                                                                                                                                                                      148.95
                                                                                                                                                                                                               

          
                                     Baby Monitor
                                             1
                                                                                                                                                                                                               39.98
                1999-05-21
        




Then the schema file written for po.xml is named po.xsd and the content is as follows:



Copy code

The code is as follows:

 
 
   Purchase order schema for Example.com.
   Copyright 2000 Example.com. All rights reserved.
 

 

 
 
 
 
  
  
  
  
 

 
 

 
 
  
  
  
  
  
 

  www.jb51.net
 

 
 
  
   
    
     
     
      
       
        
       

      

     

     
     
     
    

    
   

  

 

 

 
 
 
  
 

 


使用 xmllint 对 po.xml 文件进行校验:
复制代码 代码如下:
$ xmllint   -schema po.xsd po.xml
如果无出错信息,就说明校验通过了。

希望本文所述对大家的PHP程序设计有所帮助。

www.bkjia.comtruehttp://www.bkjia.com/PHPjc/928228.htmlTechArticlePHP使用xmllint命令处理xml与html的方法,xmllintxml 本文实例讲述了PHP使用xmllint命令处理xml与html的方法。分享给大家供大家参考。具体分析如下...
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

AI Hentai Generator

AI Hentai Generator

Generate AI Hentai for free.

Hot Article

R.E.P.O. Energy Crystals Explained and What They Do (Yellow Crystal)
2 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Repo: How To Revive Teammates
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌
Hello Kitty Island Adventure: How To Get Giant Seeds
4 weeks ago By 尊渡假赌尊渡假赌尊渡假赌

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

CakePHP Project Configuration CakePHP Project Configuration Sep 10, 2024 pm 05:25 PM

In this chapter, we will understand the Environment Variables, General Configuration, Database Configuration and Email Configuration in CakePHP.

PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian PHP 8.4 Installation and Upgrade guide for Ubuntu and Debian Dec 24, 2024 pm 04:42 PM

PHP 8.4 brings several new features, security improvements, and performance improvements with healthy amounts of feature deprecations and removals. This guide explains how to install PHP 8.4 or upgrade to PHP 8.4 on Ubuntu, Debian, or their derivati

CakePHP Date and Time CakePHP Date and Time Sep 10, 2024 pm 05:27 PM

To work with date and time in cakephp4, we are going to make use of the available FrozenTime class.

CakePHP File upload CakePHP File upload Sep 10, 2024 pm 05:27 PM

To work on file upload we are going to use the form helper. Here, is an example for file upload.

CakePHP Routing CakePHP Routing Sep 10, 2024 pm 05:25 PM

In this chapter, we are going to learn the following topics related to routing ?

Discuss CakePHP Discuss CakePHP Sep 10, 2024 pm 05:28 PM

CakePHP is an open-source framework for PHP. It is intended to make developing, deploying and maintaining applications much easier. CakePHP is based on a MVC-like architecture that is both powerful and easy to grasp. Models, Views, and Controllers gu

How To Set Up Visual Studio Code (VS Code) for PHP Development How To Set Up Visual Studio Code (VS Code) for PHP Development Dec 20, 2024 am 11:31 AM

Visual Studio Code, also known as VS Code, is a free source code editor — or integrated development environment (IDE) — available for all major operating systems. With a large collection of extensions for many programming languages, VS Code can be c

CakePHP Creating Validators CakePHP Creating Validators Sep 10, 2024 pm 05:26 PM

Validator can be created by adding the following two lines in the controller.

See all articles