Managing Log Files

Logger is part of the CategoryAplTree project.

Overview

This class offers methods useful to write and manage ordinary ANSI log files. In case any non-ANSI chars are part of a message these characters are replaced by question marks. In case you need Unicode log files you can achieve this by setting the encoding property to "UTF8".

By default the class creates a log file with the name "yyyymmdd.log". When a new day puts in an appearance this file is closed and a new one is opened automatically.

Instead of accepting the defaults you can also let the class create "yyyymm.log" files or even "yyyy.log".

Note that the main method, Log, does not do any kind of fancy formatting. It just accepts vectors of any kind as well as text matrices; performance is considered to be paramount. However, the method LogError is different: in the event of errors performance considerations are less important. You won't have millions of errors to log and if you have something else to worry about.

Note that by default the class makes intense use of error trapping to make sure that neither Log nor LogError will effect the hosting application.

Sample session

This code:

 myLogger←⎕NEW #.Logger(,⊂'')
⍝ Exercise the "Log" method"
 myLogger.Log'this is my first entry!'
 myLogger.Log'Even' 'more' 'entries'
 myLogger.Log⊃'A' 'text' 'matrix'
 myLogger.Log 1 2 3
 myLogger.Log('String')(⍳6)('Another string')
 myLogger.Log(1 2)(2 3⍴⍳6) ⍝ causes an error (trapped!)
 {myLogger.Log'Log entry written in a thread'}&⍬
⍝ Exercise the "LogError" method
 msg←'An error has occured'
 rc←0
 myLogger.LogError rc msg  ⍝ This has no effect: rc is 0
 rc←2
 myLogger.LogError rc msg
 more←'A fatal error has occured'(20 1009)((1 2)'FATAL'(2 3⍴⍳6))
 myLogger.LogError rc msg more ⍝ "more" can be any array

Results in this log file:

2011-05-29 07:29:36 *** Log File opened                 
2011-05-29 07:29:36 this is my first entry!             
2011-05-29 07:29:36 Even                                
2011-05-29 07:29:36 more                                
2011-05-29 07:29:36 entries                             
2011-05-29 07:29:36 A                                   
2011-05-29 07:29:36 text                                
2011-05-29 07:29:36 matrix                              
2011-05-29 07:29:36 1 2 3                               
2011-05-29 07:29:36 String                              
2011-05-29 07:29:36 1 2 3 4 5 6                         
2011-05-29 07:29:36 Another string                      
2011-05-29 07:29:36 (2) Log entry written in a thread   
2011-05-29 07:29:36 *** ERROR RC=2; An error has occured
2011-05-29 07:29:36 *** ERROR RC=2; An error has occured
2011-05-29 07:29:36           A fatal error has occured 
2011-05-29 07:29:36           20 1009                   
2011-05-29 07:29:36            1 2  FATAL  1 2 3        
2011-05-29 07:29:36                        4 5 6        

Note that for the log entry written from its own thread the thread number is reported in the log file.

Constructors, fields, properties and methods

]ADOC.List Logger
*** Logger (Class) ***

Constructors:
  make0
  make1(y)
  make2(path_ encoding_)
  make3(path_ encoding_ filenameType_)
  make4(path_ encoding_ filenameType_ debug_)
  make5(path_ encoding_ filenameType_ debug_ timestamp_)
  make6(path_ encoding_ filenameType_ debug_ timestamp_ refToUtils_)
Instance Properties:
  active
  autoReOpen
  debug
  encoding (ReadOnly)
  errorCounter (ReadOnly)
  errorPrefix
  extension
  fileFlag
  filenameDescriptor (ReadOnly)
  filenamePostfix
  filenamePrefix
  filenameType
  filename (ReadOnly)
  path (ReadOnly)
  printToSession
  refToUtils
  timestamp
Instance Methods:
  Close
  r ← FullFilename
  {r} ← LogError y
  {r} ← Log Msg
Shared Methods:
  r ← Copyright
  r ← CreatePropertySpace
  r ← History
  r ← Version

Project Page

For bug reports, future enhancements and a full version history see Logger/ProjectPage

Version Information

Download

You have two options: you can either download the script for usage:

Download Logger script right now

or get the whole thing from the AplWikiRepository, including the development workspace and the script and maybe more for any development or for running the test cases:

svn list svn://aplteam.com/os/dyalog/Logger/tags

If you plan to contribute please note that all stuff published as part of the APLAPL project must follow certain APLAPL-specific standards.

CategoryAplApl