Useful filter hints

LogExpert

Hints and tips for using the filter

The filter function can be a very powerful feature if used in the right way. So be creative in using the filter for your daily work with logfiles! Here are some hints and use cases you might be interested in.

Use a filter on filter tabs

A filter tab window is like a normal logfile window. That means you can use a filter on that window. So you can filter an already filtered content - it's like a filter chain. In combination with the Back Spread and Fore Spread settings you can find issues in your logfiles that would be hard to find with traditional search functions.

Example:

Your customer says: "Sometimes I get an error message when using the function 'PlaySound' in your software". There are no date or time for you to narrow the search. All you have is 15 MBs of logfiles and that improper error message of your customer. The word "error" appears often in the logfile (because it sometimes reflects a normal user error situation). The word "PlaySound" appears very often too (in a non-error context). How to find the sporadic error when using the function "PlaySound"?

·      Use the filter to search for "PlaySound".

·      Before doing the search, adjust the 'Fore Spread' to a value that is usefull to include some log messages around the "PlaySound" log entry. Use 'Back Spread' too, if needed.

·      Use 'Filter to tab' to see the filter results in a new tab window. 

·      Use a new filter on the new tab and search for the word "error"

Now you have all "error" log messages that appear in the near of the "PlaySound" messages.

The range search

Range search is useful for logfile content that is marked by some kind of start and end items (e.g. all kinds of XML tags).

Example:

You have an application that writes XML to some kind of external interface. For diagnostic reasons the output is also written to the logfile:

<output>

  ...some content...

</output>

If you are interested only in the output XML content you can use the range search in the filter. Use "<output>" as first search item and "</output>" as second search item (enable "Range search" in the advanced filter view). The filter result will include all the lines from "<output>" to "</output>".

Locate line in original file

There's an menu item called 'Locate filtered line in original file' in the context menu of every filter tab. When you choose this item you can quickly jump to the appropriate position in your original file tab.