在xmlstarlet中按文本值选择节点

Question

我试图提取'Value'节点的值,其中'Key'节点在bash shell中是'state':

<FrontendStatus xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" version="1.0" serializerVersion="1.1">
<script/>
 <State>
  <String>
   ...
   ...
  </String>
  <String>
   ...
   ...
  </String>
  <String>
   <Key>state</Key>
   <Value>WatchingLiveTV</Value>
  </String>
  <String>
   <Key>studiolevels</Key>
   <Value>1</Value>
  </String>
  <String>
   ...
   ...
  </String>
  <String>
   ...
   ...
  </String>
 </State>
</FrontendStatus>

如果我直接引用节点,我可以提取值:

$ xmlstarlet sel -t -m '/FrontendStatus[1]/State[1]/String[31]' -v Value <status.xml
WatchingLiveTV

但我想通过'Key'节点的值来选择它

Answer 1

这个XPath将选择Value的State基于其Key等于state:

/FrontendStatus/State/String[Key='state']/Value

或者,在xmlstarlet中:

$ xmlstarlet sel -t -m "/FrontendStatus/State/String[Key='state']" -v Value <status.xml

WatchingLiveTV将按要求返回.