Dart Logging

Dart logging

The C++ programs in the DART package include a detailed logfile system that can be used to obtain extra information or diagnose problems.

These logging options are accessible via command-line options which can be listed using the --help option (they're right at the top of the list of options, so you may have to scroll back to read them).

Coarse-grained control over which log messages are shown can be achieved by specifying a numeric logging level, e.g. -log 6. Lower logging-levels are more verbose. Level 5 is the default, offering an intermediate level of verbose chattiness. Level 9 prints almost nothing; level 6 prints some messages; level 3 prints lots of stuff; and level 0 prints way more than you need.

Fine-grained control over logging messages can be achieved using the "log-tag" syntax. A description of this syntax can be found via the -loghelp option.

Here are all the logging-related options:

Option	Meaning
-loghelp	print description of log-tag syntax
-logfile <FILE>	send log messages to a file, instead of to standard error
-logcopy <FILE>	send log messages to a file AND to standard error
==-logtime==	add pseudo-XML timestamps to each log message (NB file-directed logging output is automatically timestamped)
==-nologxml==	use plain-text timestamps, instead of XML
-log LEVEL	print log messages down to numeric level LEVEL (e.g. -log 3). Lower log levels are more verbose; 5 is the default, 9 is almost silent.
-q, --quiet	Equivalent to -log 9. Turns off most logging, except errors and major warnings.
-log TAG	print log messages in pieces of code tagged with string TAG (e.g. -log RATE_EM). Using this form may significantly slow things down, since it pulls in a lot of regexp code
-logtags	print a terse list of all valid logging tags (caution: may be out of date...)
-logtaginfo	print a detailed index of all logging tags (caution: may be out of date...)

Logfiles can be examined, filtered and rendered in ANSI terminal color using the fabulous dartlog.pl script, which can be found in dart/perl.

-- Ian Holmes - 18 Jul 2008