Hi,

I'm trying to use the xm_multiline module with nxlog to forward content of a logfile to logstash The log contains different xml elements which are properly indented (opening and closing elements are located at the start of the line) . E.g.

<data
    version="x"
    xmlns:bla="http://www.example.com/bla">
    <val:InfoSet>
      ...
        ...
          ...
    </val:InfoSet>
</data>

<message  ...>
    <ns>bla</ns>
    ...
        ...
</message>

Because the elements have different names, I can only use < and </ to find the start and end line. I was hoping a filter like this should be enough to select the correct lines:

HeaderLine  /^</
EndLine     /^<//

But somehow nxlog gets confused with the / in the regex pattern. I also tried escaping which dindn't help. More testing showed that it needs at least one letter. I tried to specify all letters via regex but that didn't work:

HeaderLine  /^<[a-z]/

Only way that seems to work is to specify all letters in the square braket (with the exception of the lettern, which breaks). 

HeaderLine  /^<[abcdefghijklmopqrstuvwxyz]/    (left out n)

Here all my test results.

These lines worked:

HeaderLine  /^<m/
EndLine     /^</m/

HeaderLine  /^<m/
EndLine     /^<\/m/

HeaderLine  /^<[abcdefghijklm]/
EndLine     /^<\/[abcdefghijklm]/

HeaderLine  /^<[abcdefghijklmo]/
EndLine     /^<\/[abcdefghijklmo]/

HeaderLine  /^<[abcdefghijklmopqrstuvwxyz]/    (left out n)
EndLine     /^<\/[abcdefghijklmopqrstuvwxyz]/

HeaderLine  /^<[abcdefghijklmopqrstuvwxyz]/ (left out n + not escaped
EndLine     /^</[abcdefghijklmopqrstuvwxyz]/

These lines didn't work:

HeaderLine  /^</
EndLine     /^</m/

HeaderLine  /^<[a-z]/
EndLine     /^</m/

HeaderLine  /^<\w/
EndLine     /^</m/

HeaderLine  /^<[abcdefghijklmn]/
EndLine     /^<\/[abcdefghijklmn]/

HeaderLine  /^<[bcdefghijklmn]/
EndLine     /^<\/[bcdefghijklmn]/

HeaderLine  /^<[abcdefghijklmopqrstuvwxyzn]/
EndLine     /^<\/[abcdefghijklmopqrstuvwxyzn]/

HeaderLine  /^<[abcdefghijklmnopqrstuvwxyz]/
EndLine     /^</[abcdefghijklmnopqrstuvwxyz]/

Right now I still have a problem because many of my bessages start with <n. I think this is a bug in the module. Can you confirm so I can open a ticket? Thanks
 

Fyi, this is a duplicate of http://stackoverflow.com/questions/27429234/which-headerline-and-endline-for-multiline-xml-with-different-elements