mirror of
https://gitlab.gnome.org/GNOME/glib.git
synced 2025-05-03 12:36:53 +02:00
a5c0df554e
Thu Sep 7 12:35:35 2000 Owen Taylor <otaylor@redhat.com>
* Some further makefile improvement.
* Restore all the docs that mysteriously vanished earlier.
203 lines
5.7 KiB
Plaintext
203 lines
5.7 KiB
Plaintext
<!-- ##### SECTION Title ##### -->
|
|
Message Output and Debugging Functions
|
|
|
|
<!-- ##### SECTION Short_Description ##### -->
|
|
functions to output messages and help debug applications.
|
|
|
|
<!-- ##### SECTION Long_Description ##### -->
|
|
<para>
|
|
These functions provide support for outputting messages.
|
|
</para>
|
|
|
|
<!-- ##### SECTION See_Also ##### -->
|
|
<para>
|
|
|
|
</para>
|
|
|
|
<!-- ##### FUNCTION g_print ##### -->
|
|
<para>
|
|
Outputs a formatted message via the print handler.
|
|
The default print handler simply outputs the message to stdout.
|
|
</para>
|
|
<para>
|
|
g_print() should not be used from within libraries for debugging messages,
|
|
since it may be redirected by applications to special purpose message
|
|
windows or even files.
|
|
Instead, libraries should use g_log(), or the convenience functions
|
|
g_message(), g_warning() and g_error().
|
|
</para>
|
|
|
|
@format: the message format. See the <function>printf()</function>
|
|
documentation.
|
|
@Varargs: the parameters to insert into the format string.
|
|
|
|
|
|
<!-- ##### FUNCTION g_set_print_handler ##### -->
|
|
<para>
|
|
Sets the print handler.
|
|
Any messages passed to g_print() will be output via the new handler.
|
|
The default handler simply outputs the message to stdout.
|
|
By providing your own handler you can redirect the output, to a GTK
|
|
widget or a log file for example.
|
|
</para>
|
|
|
|
@func: the new print handler.
|
|
@Returns: the old print handler.
|
|
|
|
|
|
<!-- ##### USER_FUNCTION GPrintFunc ##### -->
|
|
<para>
|
|
Specifies the type of the print handler functions.
|
|
These are called with the complete formatted string to output.
|
|
</para>
|
|
|
|
@string: the message to be output.
|
|
|
|
|
|
<!-- ##### FUNCTION g_printerr ##### -->
|
|
<para>
|
|
Outputs a formatted message via the error message handler.
|
|
The default handler simply outputs the message to stderr.
|
|
</para>
|
|
<para>
|
|
g_printerr() should not be used from within libraries. Instead g_log() should
|
|
be used, or the convenience functions g_message(), g_warning() and g_error().
|
|
</para>
|
|
|
|
@format: the message format. See the <function>printf()</function>
|
|
documentation.
|
|
@Varargs: the parameters to insert into the format string.
|
|
|
|
|
|
<!-- ##### FUNCTION g_set_printerr_handler ##### -->
|
|
<para>
|
|
Sets the handler for printing error messages.
|
|
Any messages passed to g_printerr() will be output via the new handler.
|
|
The default handler simply outputs the message to stderr.
|
|
By providing your own handler you can redirect the output, to a GTK
|
|
widget or a log file for example.
|
|
</para>
|
|
|
|
@func: the new error message handler.
|
|
@Returns: the old error message handler.
|
|
|
|
|
|
<!-- ##### MACRO g_return_if_fail ##### -->
|
|
<para>
|
|
Returns from the current function if the expression is not true.
|
|
If the expression evaluates to FALSE, a critical message is logged and
|
|
the function returns. This can only be used in functions which do not return
|
|
a value.
|
|
</para>
|
|
|
|
@expr: the expression to check.
|
|
|
|
|
|
<!-- ##### MACRO g_return_val_if_fail ##### -->
|
|
<para>
|
|
Returns from the current function, returning the value @val, if the expression
|
|
is not true.
|
|
If the expression evaluates to FALSE, a critical message is logged and
|
|
@val is returned.
|
|
</para>
|
|
|
|
@expr: the expression to check.
|
|
@val: the value to return from the current function if the expression is not
|
|
true.
|
|
|
|
|
|
<!-- ##### MACRO g_return_if_reached ##### -->
|
|
<para>
|
|
|
|
</para>
|
|
|
|
|
|
|
|
<!-- ##### MACRO g_return_val_if_reached ##### -->
|
|
<para>
|
|
|
|
</para>
|
|
|
|
@val:
|
|
|
|
|
|
<!-- ##### MACRO g_assert ##### -->
|
|
<para>
|
|
Debugging macro to terminate the application if the assertion fails.
|
|
If the assertion fails (i.e. the expression is not true), an error message
|
|
is logged and the application is terminated.
|
|
</para>
|
|
<para>
|
|
The macro can be turned off in final releases of code by defining
|
|
G_DISABLE_ASSERT when compiling the application.
|
|
</para>
|
|
|
|
@expr: the expression to check.
|
|
|
|
|
|
<!-- ##### MACRO g_assert_not_reached ##### -->
|
|
<para>
|
|
Debugging macro to terminate the application if it is ever reached.
|
|
If it is reached, an error message is logged and the application is terminated.
|
|
</para>
|
|
<para>
|
|
The macro can be turned off in final releases of code by defining
|
|
G_DISABLE_ASSERT when compiling the application.
|
|
</para>
|
|
|
|
|
|
|
|
<!-- ##### FUNCTION g_on_error_query ##### -->
|
|
<para>
|
|
Prompts the user with "[E]xit, [H]alt, show [S]tack trace or [P]roceed".
|
|
This function is intended to be used for debugging use only.
|
|
FIXME: How do you set it up?
|
|
</para>
|
|
<para>
|
|
If Exit is selected, the application terminates with a call to
|
|
<function>_exit(0)</function>.
|
|
</para>
|
|
<para>
|
|
If Halt is selected, the application enters an infinite loop.
|
|
The infinite loop can only be stopped by killing the application,
|
|
or by setting glib_on_error_halt to FALSE (possibly via a debugger).
|
|
</para>
|
|
<para>
|
|
If Stack trace is selected, g_on_error_stack_trace() is called. This
|
|
invokes gdb, which attaches to the current process and shows a stack trace.
|
|
The prompt is then shown again.
|
|
</para>
|
|
<para>
|
|
If Proceed is selected, the function returns.
|
|
</para>
|
|
<para>
|
|
This function may cause different actions on non-unix platforms.
|
|
</para>
|
|
|
|
@prg_name: the program name, needed by gdb for the [S]tack trace option.
|
|
If @prg_name is NULL, g_get_prgname() is called to get the program name
|
|
(which will work correctly if gdk_init() or gtk_init() has been called).
|
|
|
|
|
|
<!-- ##### FUNCTION g_on_error_stack_trace ##### -->
|
|
<para>
|
|
Invokes gdb, which attaches to the current process and shows a stack trace.
|
|
Called by g_on_error_query() when the [S]tack trace option is selected.
|
|
</para>
|
|
<para>
|
|
This function may cause different actions on non-unix platforms.
|
|
</para>
|
|
|
|
@prg_name: the program name, needed by gdb for the [S]tack trace option.
|
|
If @prg_name is NULL, g_get_prgname() is called to get the program name
|
|
(which will work correctly if gdk_init() or gtk_init() has been called).
|
|
|
|
|
|
<!-- ##### MACRO G_BREAKPOINT ##### -->
|
|
<para>
|
|
Inserts a breakpoint instruction into the code (on x86 machines only).
|
|
</para>
|
|
|
|
|
|
|