[ CCode ( delegate_target = false ) ]
public LogWriterFunc writer_default
Format a structured log message and output it to the default log destination for the platform.
On Linux, this is typically the systemd journal, falling back to `stdout` or `stderr` if running from the terminal or if output is being redirected to a file.
Support for other platform-specific logging mechanisms may be added in future. Distributors of GLib may modify this function to impose their own (documented) platform-specific log writing policies.
As with default_handler, this function drops debug and informational messages unless their log domain (or `all`) is listed in the space-separated `G_MESSAGES_DEBUG` environment variable.
writer_default uses the mask set by set_always_fatal to determine which messages are fatal. When using a custom writer func instead it is up to the writer function to determine which log messages are fatal.
key–value pairs of structured data forming the log message
log level, either from LogLevelFlags, or a user-defined level
number of elements in the
user data passed to set_writer_func
g_log_writer_handled on success, g_log_writer_unhandled otherwise