The default log handler set up by GLib; [func@GLib.
log_set_default_handler] allows to install an alternate default log handler.
This is used if no log handler has been set for the particular log domain and log level combination. It outputs the message to `stderr`
or `stdout` and if the log level is fatal it calls [func@GLib.BREAKPOINT]. It automatically prints a new-line character after the message,
so one does not need to be manually included in message
.
The behavior of this log handler can be influenced by a number of environment variables:
`stderr` is used for levels [flags@GLib.LogLevelFlags.LEVEL_ERROR], [flags@GLib.LogLevelFlags.LEVEL_CRITICAL], [ flags@GLib.LogLevelFlags.LEVEL_WARNING] and [flags@GLib.LogLevelFlags.LEVEL_MESSAGE]. `stdout` is used for the rest, unless `stderr` was requested by [func@GLib.log_writer_default_set_use_stderr].
This has no effect if structured logging is enabled; see [Using Structured Logging](logging.html#using-structured-logging).
log_domain |
the log domain of the message, or `NULL` for the default `""` application domain |
log_level |
the level of the message |
message |
the message |
unused_data |
data passed from [func@GLib.log] which is unused |