Revision as of 19:35, 19 March 2016

For users: See Tracefile and Stack Trace on how to look up the logging information after some problem occurred.

For developers: See the Logging API documentation, as well. So each module defines its own log_domain. Best way to figure out what to use is to look at the top of the .c file and look for the LOG_MODULE. E.g. print-session.c defines G_LOG_DOMAIN "gnc.printing".

The rest of this page is targeted towards developers.

Logging in GnuCash

GnuCash leverages glib logging, with some historical and convenience macros. Since 2007 GnuCash has an ad-hoc layer on top of glib's "gmessage.h" logging inspired by log4j. In short, messages are logged in a given log-domain and at a specific level. The log-domain is a "."-separated path, and a table of log levels is configured. Between the two, a tree of log-level is established. Log messages are checked against the tree before being emitted.

log.conf

The special file ~/.gnucash/log.conf is checked for at gnucash start up; if present, its contents will configure the logging subsystem. The primary purpose of the configuration file it to setup a specific set of log-levels, though it's also useful for changing the default logging location from /tmp/gnucash.trace to stdout, stderr or another file.

The specific set of log paths that exist are going to be a function of the code at any given point, but some basic patterns will stabilize. As of Feb 13 2007, User:Jsled is using the following to generally raise the log level of the app, but also to get debugging detail about file-backend and U I code changes related to scheduled transactions:

   [levels]
   gnc=message
   
   gnc.bin=info
   gnc.gui=info
   gnc.backend.file=info
   
   gnc.engine.sx=debug
   gnc.app-util.sx=debug
   gnc.backend.file.sx=debug
   gnc.gui.sx=debug
   gnc.gui.frequency=debug
   
   GLib=error
   
   [output]
   to=stderr

Note that these settings are probably not suitable for your purpose, but serve as an example of what's possible.