使用 Perl 解析 XML iLO 响应文件

Question

我的 iLO HP 服务器生成了以下 XML 文件， 你有我如何解析它的任何例子吗？请参阅下面的示例 XML 文件。 我想从中提取风扇速度和温度。

<?xml version="1.0"?>
<GET_EMBEDDED_HEALTH_DATA>
<FANS>
   <FAN>
      <LABEL VALUE = "Fan 1"/>
      <ZONE VALUE = "System"/>
      <STATUS VALUE = "Ok"/>
      <SPEED VALUE = "81" UNIT="Percentage"/>
   </FAN>
   <FAN>
      <LABEL VALUE = "Fan 2"/>
      <ZONE VALUE = "System"/>
      <STATUS VALUE = "Not Installed"/>
      <SPEED VALUE = "n/a" UNIT="n/a"/>
   </FAN>
   <FAN>
      <LABEL VALUE = "Fan 3"/>
      <ZONE VALUE = "System"/>
      <STATUS VALUE = "Ok"/>
      <SPEED VALUE = "81" UNIT="Percentage"/>
   </FAN>
   <FAN>
      <LABEL VALUE = "Fan 4"/>
      <ZONE VALUE = "System"/>
      <STATUS VALUE = "Not Installed"/>
      <SPEED VALUE = "n/a" UNIT="n/a"/>
   </FAN>
   <FAN>
      <LABEL VALUE = "Fan 5"/>
      <ZONE VALUE = "CPU 1"/>
      <STATUS VALUE = "Ok"/>
      <SPEED VALUE = "81" UNIT="Percentage"/>
   </FAN>
   <FAN>
      <LABEL VALUE = "Fan 6"/>
      <ZONE VALUE = "CPU 2"/>
      <STATUS VALUE = "Not Installed"/>
      <SPEED VALUE = "n/a" UNIT="n/a"/>
   </FAN>
</FANS>
<TEMPERATURE>
   <TEMP>
      <LABEL VALUE = "Temp 1"/>
      <LOCATION VALUE = "Ambient"/>
      <STATUS VALUE = "Ok"/>
      <CURRENTREADING VALUE = "32" UNIT="Celsius"/>
      <CAUTION VALUE = "40" UNIT="Celsius"/>
      <CRITICAL VALUE = "45" UNIT="Celsius"/>
   </TEMP>
   <TEMP>
      <LABEL VALUE = "Temp 2"/>
      <LOCATION VALUE = "Memory"/>
      <STATUS VALUE = "Ok"/>
      <CURRENTREADING VALUE = "48" UNIT="Celsius"/>
      <CAUTION VALUE = "110" UNIT="Celsius"/>
      <CRITICAL VALUE = "120" UNIT="Celsius"/>
   </TEMP>
   <TEMP>
      <LABEL VALUE = "Temp 3"/>
      <LOCATION VALUE = "CPU 1"/>
      <STATUS VALUE = "Ok"/>
      <CURRENTREADING VALUE = "30" UNIT="Celsius"/>
      <CAUTION VALUE = "100" UNIT="Celsius"/>
      <CRITICAL VALUE = "100" UNIT="Celsius"/>
   </TEMP>
   <TEMP>
      <LABEL VALUE = "Temp 4"/>
      <LOCATION VALUE = "CPU 1"/>
      <STATUS VALUE = "Ok"/>
      <CURRENTREADING VALUE = "30" UNIT="Celsius"/>
      <CAUTION VALUE = "100" UNIT="Celsius"/>
      <CRITICAL VALUE = "100" UNIT="Celsius"/>
   </TEMP>
   <TEMP>
      <LABEL VALUE = "Temp 5"/>
      <LOCATION VALUE = "I/O Board"/>
      <STATUS VALUE = "Ok"/>
      <CURRENTREADING VALUE = "46" UNIT="Celsius"/>
      <CAUTION VALUE = "63" UNIT="Celsius"/>
      <CRITICAL VALUE = "68" UNIT="Celsius"/>
   </TEMP>
   <TEMP>
      <LABEL VALUE = "Temp 6"/>
      <LOCATION VALUE = "CPU 2"/>
      <STATUS VALUE = "n/a"/>
      <CURRENTREADING VALUE = "n/a" UNIT="n/a"/>
      <CAUTION VALUE = "100" UNIT="Celsius"/>
      <CRITICAL VALUE = "100" UNIT="Celsius"/>
   </TEMP>
   <TEMP>
      <LABEL VALUE = "Temp 7"/>
      <LOCATION VALUE = "CPU 2"/>
      <STATUS VALUE = "n/a"/>
      <CURRENTREADING VALUE = "n/a" UNIT="n/a"/>
      <CAUTION VALUE = "100" UNIT="Celsius"/>
      <CRITICAL VALUE = "100" UNIT="Celsius"/>
   </TEMP>
</TEMPERATURE> 

Answer 1

这取决于，并且像往常一样有很多方法可以做到这一点。主要取决于（实际）文件的大小。如果它很大，我建议在解析之前使用XML::Twig 之类的模块将其切成小块。它很小，就像您的示例文件一样，几乎可以做任何事情。例如XML::LibXML::XPathContext 可以这样做（注意：您会明智地在解析中添加一些错误检查代码并可能事先验证 xml）：

#!/us/bin/perl                                                                                          

use warnings;                                                                                            
use strict;                                                                                              

use XML::LibXML;                                                                                         
use XML::LibXML::XPathContext;                                                                           

my $parser = XML::LibXML->new();                                                                         

my $doc = $parser->parse_file('test.xml');                                                               

my @nodes = $doc->findnodes('//FAN/SPEED');                                                              

foreach my $node(@nodes){                                                                                
  printf("fan: %s %s\n", $node->getAttribute('VALUE'), $node->getAttribute('UNIT'));                     
}   

给出这个输出：

fan: 81 Percentage
fan: n/a n/a
fan: 81 Percentage
fan: n/a n/a
fan: 81 Percentage
fan: n/a n/a 

您可能需要quick intro to XPath