XpoLog help - Header Pattern
 
General
A header pattern allows the user to define a pattern that appears in the beginning of the log and contains information that is relevant to the rest of the log. For instance, the first lines of a log may contain the date in which the log was created while each log entry contains only the time information. By defining a header pattern with a date mask, XpoLog will display for each entry the complete date/time information.

How to define?
In the 'Log Pattern Administration' screen click on 'advanced' to open the header settings definition. Enter the number of lines that will be scanned to match the
Header pattern and insert in the text area the pattern that describes the header.  

Example
Log Header: LOGGER CREATION DATE :22/6/2003 
Log Header Pattern: LOGGER CREATION DATE :{date,dd/MM/yyyy}
Log pattern without using header pattern: {date,HH:mm:ss.SSS} {priority,INFO;DEBUG;ERROR;WARN}: {string}
Log pattern using header pattern: {date,HH:mm:ss.SSS;dd/MM/yyyy HH:mm:ss} {priority,INFO;DEBUG;ERROR;WARN}: {string}

Note that the date information on each record is determined from the log header.
  Additional links
         XpoLog regular patterns help
         Multi Pattern help