This module implements a set of functions for logging messages either to a console or to a file. Every message has a category that acts as a searchable hierarchical tag, and optional parameters that will be substituted into the message by replacing placeholders {1}, {2}, etc. Output have the following format:
[<timestamp>][<category>][<level>] <message after substitutions>For example,
# [2021-10-05T23:15:08][test][INFO] The path 'examples' will be used
log_info(test "The path '{1}' will be used" examples)
# send log messages in `test` to the file `test.log`
log_to_file(test test.log)
# message appended to test.log
log_warn(test "ICU not found")
# enable debug messages
log_level(test DEBUG)
# printed as well - categories maintain parent-child relation
log_info(test.nested "This message should be logged, too.")Notice the parameter examples after the main message in the example above. Use of parameters is entirely optional; they are only for readability.
Controlled logging is useful in debugging, when it's easy to add a lot of calls to message and it's hard to remove them afterwards. This is not needed with this module - just raise the logging level of the corresponding category with either a call to log_level or via
-Dlog.context.<<context name>>.level=ERROR../../cmake/Logging.cmake