Quite often, developers have text log outputs. In the good case, all logs share the same format, but often there is a strange mix due to historical reasons. Up to a certain level, impulse can parse these mixed logs and display them in a uniform way. But it might be sometimes tricky to configure. Lets assume the following example:

	NOTE     [212 745 133.974 ns] in top.HHShell.m4_top.mDist_dsp_access.r2_top : getX4LegChangeDone happened
    WARNING  [212 745 133.974 ns] in top.HHShell.m4_top.mDist_dsp_access.r4_top : getX4LegChangeDone = 0x1008000
    ISR at 214435176 
    ERROR    [214 435 176.000 ns] in top.HHShell.m4_top.mDist_dsp_wait.entry : Kernel changed state to: OUTPUT
    # Leg ok - wait for next
    NOTE00000[216 735 876.000 ns] in top.F4.generics : Calculated load 47%

Here we got

1. a default format with 'WARNING|NOTE|ERROR|DEBUG [time] where : information'
2. an ISR format with just a timing information
3. and some temporary log that shall be ignored (# Leg ok...)
    

Press "Add" and select "Log Pattern" to create a new log pattern.

A log pattern describes the form and content of one single log line. Regular expressions can be used not only to match text, but also to extract information for further processing. This is done by defining groups of characters and capturing them using the special parenthesis of ( and ) meta characters.

Define the regular expression

To play with regular expression (not always easy), the log pattern dialogue has a field to paste log lines and test them with your expression. The first expression is:

(WARNING|NOTE|ERROR|DEBUG)[\s0]*\[([ 0-9a-z\.]+)\]\s*in\s*([^:]*):\s*(.*)

(WARNING|NOTE|ERROR|DEBUG)

Group 1: log level - one of these options

[\s0]*

optional white-spaces and zeros

\[([ 0-9a-z\.]+)\]

Group 2: time stamp

\s*

optional white-spaces

in\s*([^:]*)

Group 3: logger (location) - starts at 'in' and ends at ':'

\s*

':' and optional white-spaces

(.*)

Group 4: text - remaining line

Name and configure the sample members

Log signals are struct signal with multiple members. Select member names and types for all groups that shall have a member in you log samples (e.g. the message).

Valid member types are:

• Float,
• Integer,
• Text ,
• or Enumeration.

Define the signal naming scheme

Each single sample belongs to one signal. You can organize your samples into one or multiple signals (e.g. a signal per log source). The "Signal/Scope name" section allows to select the signal and scope naming scheme for each log pattern.

In our case the logger group contains an hierarchical name using '.' as separator. If we choose Hierarchy from source value , the reader will create a hierarchy of log signals.
Select the logger group as source group and enter '\.' (regular expression) in field Separator . To differentiate logs and nodes, type in '#' (or whatever you like) in field Leaf Prefix . This is required if a node (e.g top.HHShell) has logs but also sub nodes with logs:

NOTE [212 745 133.974 ns] in top.HHShell : a log 
NOTE [212 745 133.974 ns] in top.HHShell.m4_top : a log

The reader will create folders/scope for all hierarchy nodes and signals for all loggers.

Configure the time-stamp

For the Timestamp group we need some extra information to make the reader able to parse: Select Float value (in this case 212745133.974 ns equals 212745133974 ps), the source group (here Group2), and Parse unit from value in the field Domain unit .

Set the tag group and identification patterns

Add log tags (Fatal, Error, Warning, Success, Info, Debug, Trace) to all samples. The tag modifies the presentation color and can be made visible in the complementary views. The tag patterns are regular expressions. A typical expression for the "Error" tag could be "error|Error|ERR".