logDefaultHandler
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:
G_MESSAGES_PREFIXED
: A:
-separated list of log levels for which messages should be prefixed by the program name and PID of the application.G_MESSAGES_DEBUG
: A space-separated list of log domains for which debug and informational messages are printed. By default these messages are not printed. If you need to set the allowed domains at runtime, use func@GLib.log_writer_default_set_debug_domains.
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 logging.html#using-structured-logging.
Parameters
the log domain of the message, or NULL
for the default ""
application domain
the level of the message
the message
data passed from func@GLib.log which is unused