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Introducing LogDiver

LogDiver is a new Mac OS X tool to help you view, filter and diagnose problems with your log files.


LogDiver supports the following features:

  • Importing multiple log files from multiple source applications, with the ability to define new input formats and conversion descriptors.
  • Automatically conversion of timestamps to an appropriate and consistent timezone.
  • Convenient filtering to hide/show specific types of events.

Logdiver screenshot


The Import Dialog allows you to select which log files you would like to import. Upon file selection, LogDiver will attempt to determine what type of log file it is and helpfully suggests which Extractor should be used.

By default, each extractor comes with a default date format that you can override if your log file has localised dates.

Importing a log file

Note that you can multi-select log files, but they must all use the same extractor.


There are three main ways that you can filter events from the main view. The first and best way to filter by timestamp is to use the Timeline Bar to quickly set a starting and ending time filter.

Timeline bar

The second, more granular, way to filter events out is to use the Filter View to build a predicate on a field-by-field basis.


And the third way to control what columns you can see is to Control-Click on the column headings to choose which columns are visible.

Choosing columns

Defining New Extractors

If you are unable to find a pre-built extractor to suit your log file, you can always add your own using the Extractor Editor.

Extractor icon

The Extractor Editor allows to you to define your own log file formats using regular expressions.

Regular expression groups

Using a group-based regular expression that matches your log file format, the Groups table will display as many rows as there are groups in your pattern. You can then allocate each group to the built-in LogDiver field names, and give the column an optional description.

You can also define whether the column is visible by default.

The Severity Map table allows you to enter specific strings that, when assigned to the Severity column, will be mapped to a particular severity type. For example, in some log files an error may be signified by an E in the log file. Any strings that do not have an explicit mapping will use the Unknown severity type.

Severity table

You can also provide a regular expression that will be used to assist the Import Dialog to determine whether your newly created extractor should presented as a suggested extractor. If the currently selected file matches this regular expression, your extractor will be included in the suggested extractor list.

File match regular expression

And lastly, you can optionally provide a regular expression that is used to assist LogDiver to handle log lines that have spilled over onto multiple lines. As LogDiver reads each log line from the input file, if it matches the continuation regular expression, the line will be appended to the previous line instead of being parsed as a new log event.

Continuation regular expression

Defining Your Own Log File Extractors

LogDiver also gives you the ability to define your own log file formats.


LogDiver will be available soon in the Mac App Store, however, I am currently seeking feedback from interested parties for:

  • Beta testing
  • Suggestions for specific file formats that could be included in the initial release.

Please contact me at if you would like to be involved, or to get a copy for beta testing.


  1. Matt Shepherd says:


    I just purchased and downloaded LogDiver from the app store but i dont see the “Extractor Editor” Icon to define new file formats.

    Am i missing something?

    Thanks, Matt

  2. craig says:

    Hi Matt,

    This article is for v1.0 of LogDiver (the principles still apply though). In v2.0, Extractors have been renamed as “File Formats” and there is an icon on the main toolbar called File Formats.

    While the screens have changed slightly, it is very similar to the original.

    Let me know if you need more help –


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