Question

I have got an xml file containing some attributes like

<string name="my/ attribute" optional="true">
  <description>some text</description>
  <value>some text again</value>
</string>

I would like to change the value (which does not necessarily have to be “some text again”) by the string “none”. I tried the following on the command line:

 awk '/<string name="my\/ attribute" optional="true">/,/<\/string>/ {sub(/<value>(.*)<\/value>/,"<value>none</value>")}1' my.xml > my_new.xml

This somehow works ok, but the result is as follows:

<string name="my/ attribute" optional="true">
  <description>some text</description>
  <value>some text again<\/value>
</string>

Why is the / (slash) in the tag escaped?

Thanks a lot for your help,

Daniela.

Answer 1

Assuming the inconsistencies in your question that Richard pointed out are accidental:

$ cat input.xml
<string name="my/ attribute" optional="true">
  <description>some text</description>
  <value>some text again</value>
</string>

$ awk '/<string/{doit=1} doit{sub(/<value>[^<]+<\/value>/, "<value>none</value>"); print} /<\/string>/{doit=0}' input.xml 
<string name="my/ attribute" optional="true">
  <description>some text</description>
  <value>none</value>
</string>

$ 

This is WEE bit safer than your script, in that it will handle minified XML (i.e. whitespace removed, all on e line), but it won’t handle <value> that is split over multiple lines.

I do recommend looking in to Perl’s XML::Simple or PHP’s SimpleXML. It won’t be a one-liner, but it will work MUCH more reliably.