ewPrint

ew

1998 12-05

NAME

ewPrint - output to file, console, or message window

SYNOPSIS

ewPrint(long source,long type,char *file,long line,long logger,char *format,va_list ap)

ewPrint() will format an error/log message and output it using the global EW_Output ewGlobalOutput or through the standard WBA_Logger mechanism, the latter if logger is non-zero. For a non-zero logger, format is followed by a variable number of arguments which are eventually fed into a near-equivalant of printf(). Note that you should be careful not to unintentially use printf()-style formatting character sequences. For a logger of zero, variable arguments are ignored and format is considered a fixed message.

For specific control and consistant responses, the following enumerations for source should be used:

EW_APP Incident occured in the application itself.

EW_GFX Incident occured in the graphics abstraction.

EW_WINDOW Incident occured in the window handling.

EW_EVENT Incident occured in the event handling.

EW_EW Incident occured in EW (non-specific).

EW_OS Incident occured with the Operating System.

EW_WIDGET Incident occured in the widget library.

The following enumerations for type should be used:

EW_LOG Just information, no real problem.

EW_WARN This incident may cause inaccuracies or future problems.

EW_ERROR This incident will probably cause undesired behavior or additional failures.

EW_FATAL A unrecoverable problem has occured. This currently initiates an equivalent of exit() .

EW_CRASH An intential crash is requested, presumably for debugging. This currently initiates a segmentation fault, usually followed by a core dump or debugger break.
(uses *((long *)0)=0)

The message is text describing the specific problem, preferably stating the function/member in which it occured.

The file and line are the source file and line number where ewPrint() is called. The macro EW_PRINT() determines these automatically and calls ewPrint() .

Additional output formatting is defined in the function ewPrint() itself. This may include OS-dependent error states/messages and secondary actions (such as exit() for EW_FATAL).

The output modes can be customized using the EW_Output member functions of ewGlobalOutput .

EXAMPLES


EW_PRINT(EW_EVENT,EW_WARN,"negative index %d",index)

EW_PRINT(EW_GFX,EW_ERROR,"EW_Window::SetFont(): could not set text alignment")

EW_PRINT(EW_WINDOW,EW_FATAL,"cannot connect to X server")

FILES

wds/error.h Error-handling header file

NOTES

ewPrint() is subject to change. All calls should be routed through EW_PRINT().

Non-log calls to ewPrint can clear errno. If the application needs to use errno, it should read the value prior to calling EW_PRINT().

Many messages originating from within EW and WDS such as widget dumps are upwards to 200 characters wide. Although any terminal width can be used, a 200 column shell is probably clearer.

Many messages optionally use ANSI color codes to clarify complex text or point out important information. White and black are available, but not used, since these are the common background colors. By default, terminal text coloring is on for UNIX and off for Win32.

EW_APP	Incident occured in the application itself.
EW_GFX	Incident occured in the graphics abstraction.
EW_WINDOW	Incident occured in the window handling.
EW_EVENT	Incident occured in the event handling.
EW_EW	Incident occured in EW (non-specific).
EW_OS	Incident occured with the Operating System.
EW_WIDGET	Incident occured in the widget library.

EW_LOG	Just information, no real problem.
EW_WARN	This incident may cause inaccuracies or future problems.
EW_ERROR	This incident will probably cause undesired behavior or additional failures.
EW_FATAL	A unrecoverable problem has occured. This currently initiates an equivalent of exit() .
EW_CRASH	An intential crash is requested, presumably for debugging. This currently initiates a segmentation fault, usually followed by a core dump or debugger break. (uses ((long )0)=0)