[OpenSPARC-T2-DV] / tools / src / nas,5.n2.os.2 / lib / python / man / mann / bgerror.n

'\"
'\" Copyright (c) 1990-1994 The Regents of the University of California.
'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
'\"
'\" See the file "license.terms" for information on usage and redistribution
'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
'\" 
'\" RCS: @(#) $Id: bgerror.n,v 1.4.18.1 2004/10/27 09:35:38 dkf Exp $
'\" 
'\" The definitions below are for supplemental macros used in Tcl/Tk
'\" manual entries.
'\"
'\" .AP type name in/out ?indent?
'\"	Start paragraph describing an argument to a library procedure.
'\"	type is type of argument (int, etc.), in/out is either "in", "out",
'\"	or "in/out" to describe whether procedure reads or modifies arg,
'\"	and indent is equivalent to second arg of .IP (shouldn't ever be
'\"	needed;  use .AS below instead)
'\"
'\" .AS ?type? ?name?
'\"	Give maximum sizes of arguments for setting tab stops.  Type and
'\"	name are examples of largest possible arguments that will be passed
'\"	to .AP later.  If args are omitted, default tab stops are used.
'\"
'\" .BS
'\"	Start box enclosure.  From here until next .BE, everything will be
'\"	enclosed in one large box.
'\"
'\" .BE
'\"	End of box enclosure.
'\"
'\" .CS
'\"	Begin code excerpt.
'\"
'\" .CE
'\"	End code excerpt.
'\"
'\" .VS ?version? ?br?
'\"	Begin vertical sidebar, for use in marking newly-changed parts
'\"	of man pages.  The first argument is ignored and used for recording
'\"	the version when the .VS was added, so that the sidebars can be
'\"	found and removed when they reach a certain age.  If another argument
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'\"
'\" .VE
'\"	End of vertical sidebar.
'\"
'\" .DS
'\"	Begin an indented unfilled display.
'\"
'\" .DE
'\"	End of indented unfilled display.
'\"
'\" .SO
'\"	Start of list of standard options for a Tk widget.  The
'\"	options follow on successive lines, in four columns separated
'\"	by tabs.
'\"
'\" .SE
'\"	End of list of standard options for a Tk widget.
'\"
'\" .OP cmdName dbName dbClass
'\"	Start of description of a specific option.  cmdName gives the
'\"	option's name as specified in the class command, dbName gives
'\"	the option's name in the option database, and dbClass gives
'\"	the option's class in the option database.
'\"
'\" .UL arg1 arg2
'\"	Print arg1 underlined, then print arg2 normally.
'\"
'\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $
'\"
'\"	# Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
.if t .wh -1.3i ^B
.nr ^l \n(.l
.ad b
'\"	# Start an argument description
.de AP
.ie !"\\$4"" .TP \\$4
.el \{\
.   ie !"\\$2"" .TP \\n()Cu
.   el          .TP 15
.\}
.ta \\n()Au \\n()Bu
.ie !"\\$3"" \{\
\&\\$1	\\fI\\$2\\fP	(\\$3)
.\".b
.\}
.el \{\
.br
.ie !"\\$2"" \{\
\&\\$1	\\fI\\$2\\fP
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\&\\fI\\$1\\fP
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..
'\"	# define tabbing values for .AP
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.nr )A 10n
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.\"
.if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n
.nr )C \\n()Bu+\\w'(in/out)'u+2n
..
.AS Tcl_Interp Tcl_CreateInterp in/out
'\"	# BS - start boxed text
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.if n .fi
..
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.nf
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.ie n \l'\\n(^lu\(ul'
.el \{\
.\"	Draw four-sided box normally, but don't draw top of
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.ie !\\n(^b-1 \{\
\h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
.\}
.el \}\
\h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'|0u-1.5n\(ul'
.\}
.\}
.fi
.br
.nr ^b 0
..
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..
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.ev 2
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\h'|\\n(^lu+3n'\L'|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-|\\n(^lu+3n'
.sp -1
.fi
.ev
.\}
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..
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'\"	# page bottom macro.
.de ^B
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.\"	Draw three-sided box if this is the box's first page,
.\"	draw two sides but no top otherwise.
.ie !\\n(^b-1 \h'-1.5n'\L'|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c
.el \h'-1.5n'\L'|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'|0u'\c
.\}
.if \\n(^v \{\
.nr ^x \\n(^tu+1v-\\n(^Yu
\kx\h'-\\nxu'\h'|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'|0u'\c
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.bp
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.de DS
.RS
.nf
.sp
..
'\"	# DE - end display
.de DE
.fi
.RE
.sp
..
'\"	# SO - start of list of standard options
.de SO
.SH "STANDARD OPTIONS"
.LP
.nf
.ta 5.5c 11c
.ft B
..
'\"	# SE - end of list of standard options
.de SE
.fi
.ft R
.LP
See the \\fBoptions\\fR manual entry for details on the standard options.
..
'\"	# OP - start of full description for a single option
.de OP
.LP
.nf
.ta 4c
Command-Line Name:	\\fB\\$1\\fR
Database Name:	\\fB\\$2\\fR
Database Class:	\\fB\\$3\\fR
.fi
.IP
..
'\"	# CS - begin code excerpt
.de CS
.RS
.nf
.ta .25i .5i .75i 1i
..
'\"	# CE - end code excerpt
.de CE
.fi
.RE
..
.de UL
\\$1\l'|0\(ul'\\$2
..
.TH bgerror n 7.5 Tcl "Tcl Built-In Commands"
.BS
'\" Note:  do not modify the .SH NAME line immediately below!
.SH NAME
bgerror \- Command invoked to process background errors
.SH SYNOPSIS
\fBbgerror \fImessage\fR
.BE

.SH DESCRIPTION
.PP
The \fBbgerror\fR command doesn't exist as built-in part of Tcl.  Instead,
individual applications or users can define a \fBbgerror\fR
command (e.g. as a Tcl procedure) if they wish to handle background
errors.
.PP
A background error is one that occurs in an event handler or some
other command that didn't originate with the application.
For example, if an error occurs while executing a command specified
with the \fBafter\fR command, then it is a background error.
For a non-background error, the error can simply be returned up
through nested Tcl command evaluations until it reaches the top-level
code in the application; then the application can report the error
in whatever way it wishes.  When a background error occurs, the
unwinding ends in the Tcl library and there is no obvious way for Tcl
to report the error.
.PP
When Tcl detects a background error, it saves information about the
error and invokes the \fBbgerror\fR command later as an idle event
handler. Before invoking \fBbgerror\fR, Tcl restores the
\fBerrorInfo\fR and \fBerrorCode\fR variables to their values at the
time the error occurred, then it invokes \fBbgerror\fR with the error
message as its only argument.  Tcl assumes that the application has
implemented the \fBbgerror\fR command, and that the command will
report the error in a way that makes sense for the application.  Tcl
will ignore any result returned by the \fBbgerror\fR command as long
as no error is generated.
.PP
If another Tcl error occurs within the \fBbgerror\fR command (for
example, because no \fBbgerror\fR command has been defined) then Tcl
reports the error itself by writing a message to stderr.
.PP
If several background errors accumulate before \fBbgerror\fR is
invoked to process them, \fBbgerror\fR will be invoked once for each
error, in the order they occurred.  However, if \fBbgerror\fR returns
with a break exception, then any remaining errors are skipped without
calling \fBbgerror\fR.
.PP
Tcl has no default implementation for \fBbgerror\fR. However, in
applications using Tk there is a default \fBbgerror\fR procedure which
posts a dialog box containing the error message and offers the user a
chance to see a stack trace showing where the error occurred.  In
addition to allowing the user to view the stack trace, the dialog
provides an additional application configurable button which may be
used, for example, to save the stack trace to a file.  By default,
this is the behavior associated with that button.  This behavior can
be redefined by setting the option database values
\fB*ErrorDialog.function.text\fR, to specify the caption for the
function button, and \fB*ErrorDialog.function.command\fR, to specify
the command to be run.  The text of the stack trace is appended to the
command when it is evaluated.  If either of these options is set to
the empty string, then the additional button will not be displayed in
the dialog.
.PP
If you are writing code that will be used by others as part of a
package or other kind of library, consider avoiding \fBbgerror\fR.
The reason for this is that the application programmer may also want
to define a \fBbgerror\fR, or use other code that does and thus will
have trouble integrating your code.
.SH "EXAMPLE"
This \fBbgerror\fR procedure appends errors to a file, with a timestamp.
.CS
proc bgerror {message} {
    set timestamp [clock format [clock seconds]]
    set fl [open mylog.txt {WRONLY CREAT APPEND}]
    puts $fl "$timestamp: bgerror in $::argv '$message'"
    close $fl
}
.CE

.SH "SEE ALSO"
after(n), tclvars(n)

.SH KEYWORDS
background error, reporting
Commit	Line	Data
86530b38 AT	1	'\"
	2	'\" Copyright (c) 1990-1994 The Regents of the University of California.
	3	'\" Copyright (c) 1994-1996 Sun Microsystems, Inc.
	4	'\"
	5	'\" See the file "license.terms" for information on usage and redistribution
	6	'\" of this file, and for a DISCLAIMER OF ALL WARRANTIES.
	7	'\"
	8	'\" RCS: @(#) $Id: bgerror.n,v 1.4.18.1 2004/10/27 09:35:38 dkf Exp $
	9	'\"
	10	'\" The definitions below are for supplemental macros used in Tcl/Tk
	11	'\" manual entries.
	12	'\"
	13	'\" .AP type name in/out ?indent?
	14	'\" Start paragraph describing an argument to a library procedure.
	15	'\" type is type of argument (int, etc.), in/out is either "in", "out",
	16	'\" or "in/out" to describe whether procedure reads or modifies arg,
	17	'\" and indent is equivalent to second arg of .IP (shouldn't ever be
	18	'\" needed; use .AS below instead)
	19	'\"
	20	'\" .AS ?type? ?name?
	21	'\" Give maximum sizes of arguments for setting tab stops. Type and
	22	'\" name are examples of largest possible arguments that will be passed
	23	'\" to .AP later. If args are omitted, default tab stops are used.
	24	'\"
	25	'\" .BS
	26	'\" Start box enclosure. From here until next .BE, everything will be
	27	'\" enclosed in one large box.
	28	'\"
	29	'\" .BE
	30	'\" End of box enclosure.
	31	'\"
	32	'\" .CS
	33	'\" Begin code excerpt.
	34	'\"
	35	'\" .CE
	36	'\" End code excerpt.
	37	'\"
	38	'\" .VS ?version? ?br?
	39	'\" Begin vertical sidebar, for use in marking newly-changed parts
	40	'\" of man pages. The first argument is ignored and used for recording
	41	'\" the version when the .VS was added, so that the sidebars can be
	42	'\" found and removed when they reach a certain age. If another argument
	43	'\" is present, then a line break is forced before starting the sidebar.
	44	'\"
	45	'\" .VE
	46	'\" End of vertical sidebar.
	47	'\"
	48	'\" .DS
	49	'\" Begin an indented unfilled display.
	50	'\"
	51	'\" .DE
	52	'\" End of indented unfilled display.
	53	'\"
	54	'\" .SO
	55	'\" Start of list of standard options for a Tk widget. The
	56	'\" options follow on successive lines, in four columns separated
	57	'\" by tabs.
	58	'\"
	59	'\" .SE
	60	'\" End of list of standard options for a Tk widget.
	61	'\"
	62	'\" .OP cmdName dbName dbClass
	63	'\" Start of description of a specific option. cmdName gives the
	64	'\" option's name as specified in the class command, dbName gives
65	'\" the option's name in the option database, and dbClass gives
66	'\" the option's class in the option database.
67	'\"
68	'\" .UL arg1 arg2
69	'\" Print arg1 underlined, then print arg2 normally.
70	'\"
71	'\" RCS: @(#) $Id: man.macros,v 1.4 2000/08/25 06:18:32 ericm Exp $
72	'\"
73	'\" # Set up traps and other miscellaneous stuff for Tcl/Tk man pages.
74	.if t .wh -1.3i ^B
75	.nr ^l \n(.l
76	.ad b
77	'\" # Start an argument description
78	.de AP
79	.ie !"\\$4"" .TP \\$4
80	.el \{\
81	. ie !"\\$2"" .TP \\n()Cu
82	. el .TP 15
83	.\}
84	.ta \\n()Au \\n()Bu
85	.ie !"\\$3"" \{\
86	\&\\$1 \\fI\\$2\\fP (\\$3)
87	.\".b
88	.\}
89	.el \{\
90	.br
91	.ie !"\\$2"" \{\
92	\&\\$1 \\fI\\$2\\fP
93	.\}
94	.el \{\
95	\&\\fI\\$1\\fP
96	.\}
97	.\}
98	..
99	'\" # define tabbing values for .AP
100	.de AS
101	.nr )A 10n
102	.if !"\\$1"" .nr )A \\w'\\$1'u+3n
103	.nr )B \\n()Au+15n
104	.\"
105	.if !"\\$2"" .nr )B \\w'\\$2'u+\\n()Au+3n
106	.nr )C \\n()Bu+\\w'(in/out)'u+2n
107	..
108	.AS Tcl_Interp Tcl_CreateInterp in/out
109	'\" # BS - start boxed text
110	'\" # ^y = starting y location
111	'\" # ^b = 1
112	.de BS
113	.br
114	.mk ^y
115	.nr ^b 1u
116	.if n .nf
117	.if n .ti 0
118	.if n \l'\\n(.lu\(ul'
119	.if n .fi
120	..
121	'\" # BE - end boxed text (draw box now)
122	.de BE
123	.nf
124	.ti 0
125	.mk ^t
126	.ie n \l'\\n(^lu\(ul'
127	.el \{\
128	.\" Draw four-sided box normally, but don't draw top of
129	.\" box if the box started on an earlier page.
130	.ie !\\n(^b-1 \{\
131	\h'-1.5n'\L'\|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\l'\|0u-1.5n\(ul'
132	.\}
133	.el \}\
134	\h'-1.5n'\L'\|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\l'\|0u-1.5n\(ul'
135	.\}
136	.\}
137	.fi
138	.br
139	.nr ^b 0
140	..
141	'\" # VS - start vertical sidebar
142	'\" # ^Y = starting y location
143	'\" # ^v = 1 (for troff; for nroff this doesn't matter)
144	.de VS
145	.if !"\\$2"" .br
146	.mk ^Y
147	.ie n 'mc \s12\(br\s0
148	.el .nr ^v 1u
149	..
150	'\" # VE - end of vertical sidebar
151	.de VE
152	.ie n 'mc
153	.el \{\
154	.ev 2
155	.nf
156	.ti 0
157	.mk ^t
158	\h'\|\\n(^lu+3n'\L'\|\\n(^Yu-1v\(bv'\v'\\n(^tu+1v-\\n(^Yu'\h'-\|\\n(^lu+3n'
159	.sp -1
160	.fi
161	.ev
162	.\}
163	.nr ^v 0
164	..
165	'\" # Special macro to handle page bottom: finish off current
166	'\" # box/sidebar if in box/sidebar mode, then invoked standard
167	'\" # page bottom macro.
168	.de ^B
169	.ev 2
170	'ti 0
171	'nf
172	.mk ^t
173	.if \\n(^b \{\
174	.\" Draw three-sided box if this is the box's first page,
175	.\" draw two sides but no top otherwise.
176	.ie !\\n(^b-1 \h'-1.5n'\L'\|\\n(^yu-1v'\l'\\n(^lu+3n\(ul'\L'\\n(^tu+1v-\\n(^yu'\h'\|0u'\c
177	.el \h'-1.5n'\L'\|\\n(^yu-1v'\h'\\n(^lu+3n'\L'\\n(^tu+1v-\\n(^yu'\h'\|0u'\c
178	.\}
179	.if \\n(^v \{\
180	.nr ^x \\n(^tu+1v-\\n(^Yu
181	\kx\h'-\\nxu'\h'\|\\n(^lu+3n'\ky\L'-\\n(^xu'\v'\\n(^xu'\h'\|0u'\c
182	.\}
183	.bp
184	'fi
185	.ev
186	.if \\n(^b \{\
187	.mk ^y
188	.nr ^b 2
189	.\}
190	.if \\n(^v \{\
191	.mk ^Y
192	.\}
193	..
194	'\" # DS - begin display
195	.de DS
196	.RS
197	.nf
198	.sp
199	..
200	'\" # DE - end display
201	.de DE
202	.fi
203	.RE
204	.sp
205	..
206	'\" # SO - start of list of standard options
207	.de SO
208	.SH "STANDARD OPTIONS"
209	.LP
210	.nf
211	.ta 5.5c 11c
212	.ft B
213	..
214	'\" # SE - end of list of standard options
215	.de SE
216	.fi
217	.ft R
218	.LP
219	See the \\fBoptions\\fR manual entry for details on the standard options.
220	..
221	'\" # OP - start of full description for a single option
222	.de OP
223	.LP
224	.nf
225	.ta 4c
226	Command-Line Name: \\fB\\$1\\fR
227	Database Name: \\fB\\$2\\fR
228	Database Class: \\fB\\$3\\fR
229	.fi
230	.IP
231	..
232	'\" # CS - begin code excerpt
233	.de CS
234	.RS
235	.nf
236	.ta .25i .5i .75i 1i
237	..
238	'\" # CE - end code excerpt
239	.de CE
240	.fi
241	.RE
242	..
243	.de UL
244	\\$1\l'\|0\(ul'\\$2
245	..
246	.TH bgerror n 7.5 Tcl "Tcl Built-In Commands"
247	.BS
248	'\" Note: do not modify the .SH NAME line immediately below!
249	.SH NAME
250	bgerror \- Command invoked to process background errors
251	.SH SYNOPSIS
252	\fBbgerror \fImessage\fR
253	.BE
254
255	.SH DESCRIPTION
256	.PP
257	The \fBbgerror\fR command doesn't exist as built-in part of Tcl. Instead,
258	individual applications or users can define a \fBbgerror\fR
259	command (e.g. as a Tcl procedure) if they wish to handle background
260	errors.
261	.PP
262	A background error is one that occurs in an event handler or some
263	other command that didn't originate with the application.
264	For example, if an error occurs while executing a command specified
265	with the \fBafter\fR command, then it is a background error.
266	For a non-background error, the error can simply be returned up
267	through nested Tcl command evaluations until it reaches the top-level
268	code in the application; then the application can report the error
269	in whatever way it wishes. When a background error occurs, the
270	unwinding ends in the Tcl library and there is no obvious way for Tcl
271	to report the error.
272	.PP
273	When Tcl detects a background error, it saves information about the
274	error and invokes the \fBbgerror\fR command later as an idle event
275	handler. Before invoking \fBbgerror\fR, Tcl restores the
276	\fBerrorInfo\fR and \fBerrorCode\fR variables to their values at the
277	time the error occurred, then it invokes \fBbgerror\fR with the error
278	message as its only argument. Tcl assumes that the application has
279	implemented the \fBbgerror\fR command, and that the command will
280	report the error in a way that makes sense for the application. Tcl
281	will ignore any result returned by the \fBbgerror\fR command as long
282	as no error is generated.
283	.PP
284	If another Tcl error occurs within the \fBbgerror\fR command (for
285	example, because no \fBbgerror\fR command has been defined) then Tcl
286	reports the error itself by writing a message to stderr.
287	.PP
288	If several background errors accumulate before \fBbgerror\fR is
289	invoked to process them, \fBbgerror\fR will be invoked once for each
290	error, in the order they occurred. However, if \fBbgerror\fR returns
291	with a break exception, then any remaining errors are skipped without
292	calling \fBbgerror\fR.
293	.PP
294	Tcl has no default implementation for \fBbgerror\fR. However, in
295	applications using Tk there is a default \fBbgerror\fR procedure which
296	posts a dialog box containing the error message and offers the user a
297	chance to see a stack trace showing where the error occurred. In
298	addition to allowing the user to view the stack trace, the dialog
299	provides an additional application configurable button which may be
300	used, for example, to save the stack trace to a file. By default,
301	this is the behavior associated with that button. This behavior can
302	be redefined by setting the option database values
303	\fB*ErrorDialog.function.text\fR, to specify the caption for the
304	function button, and \fB*ErrorDialog.function.command\fR, to specify
305	the command to be run. The text of the stack trace is appended to the
306	command when it is evaluated. If either of these options is set to
307	the empty string, then the additional button will not be displayed in
308	the dialog.
309	.PP
310	If you are writing code that will be used by others as part of a
311	package or other kind of library, consider avoiding \fBbgerror\fR.
312	The reason for this is that the application programmer may also want
313	to define a \fBbgerror\fR, or use other code that does and thus will
314	have trouble integrating your code.
315	.SH "EXAMPLE"
316	This \fBbgerror\fR procedure appends errors to a file, with a timestamp.
317	.CS
318	proc bgerror {message} {
319	set timestamp [clock format [clock seconds]]
320	set fl [open mylog.txt {WRONLY CREAT APPEND}]
321	puts $fl "$timestamp: bgerror in $::argv '$message'"
322	close $fl
323	}
324	.CE
325
326	.SH "SEE ALSO"
327	after(n), tclvars(n)
328
329	.SH KEYWORDS
330	background error, reporting