How to pattern multiline XML using RegEx in NXLog

You should be able to use nxlog's xm_multiline module and specify the regexp in the HeaderLine directive.If you add a capturing rule to the regexp to match the XML part (stuff after the [..]) then you should be able to parse the XML with xm_xml's parse_xml().

There is a similar example here.

Try doing this using a multiline ReGex :

$ perl -0777 -ne 'print $& if !<RESPONSE>.*</RESPONSE>!s' file

Setting the input/output separator as undef (-0777) will slurp the whole file in memory

Output:

<RESPONSE>  <RESPONSE_TEXT>Operation SUCCESSFUL</RESPONSE_TEXT>  <RESULT>OK</RESULT>  <RESULT_CODE>-1</RESULT_CODE>  <TERMINATION_STATUS>SUCCESS</TERMINATION_STATUS>  <COUNTER>221</COUNTER>  <SECONDARY_DATA>12</SECONDARY_DATA>  <MACLABEL_IN_SESSION>P_061</MACLABEL_IN_SESSION>  <SESSION_DURATION>00:00:16</SESSION_DURATION>  <INVOICE_SESSION>XX</INVOICE_SESSION>  <SERIAL_NUMBER>XX</SERIAL_NUMBER></RESPONSE>

In a script :

BEGIN { $/ = undef; $\ = undef; } # input/output separator as undefwhile (defined($_ = <ARGV>)) {    print $& if m[<RESPONSE>.*</RESPONSE>]s;}

from perldoc perlre for modifier 's'

 s   Treat string as single line. That is, change "." to match any     character whatsoever, even a newline, which normally it would not     match.