+++ /dev/null
-'\"
-'\" Copyright (c) 1992-1994 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.
-'\"
-.TH Tcl_BackgroundError 3 7.5 Tcl "Tcl Library Procedures"
-.so man.macros
-.BS
-.SH NAME
-Tcl_BackgroundException, Tcl_BackgroundError \- report Tcl exception that occurred in background processing
-.SH SYNOPSIS
-.nf
-\fB#include <tcl.h>\fR
-.sp
-\fBTcl_BackgroundException\fR(\fIinterp, code\fR)
-.sp
-\fBTcl_BackgroundError\fR(\fIinterp\fR)
-.SH ARGUMENTS
-.AS Tcl_Interp *interp
-.AP Tcl_Interp *interp in
-Interpreter in which the exception occurred.
-.AP int code in
-The exceptional return code to be reported.
-.BE
-
-.SH DESCRIPTION
-.PP
-This procedure is typically invoked when a Tcl exception (any
-return code other than TCL_OK) occurs during
-.QW "background processing"
-such as executing an event handler.
-When such an exception occurs, the condition is reported to Tcl
-or to a widget or some other C code, and there is not usually any
-obvious way for that code to report the exception to the user.
-In these cases the code calls \fBTcl_BackgroundException\fR with an
-\fIinterp\fR argument identifying the interpreter in which the
-exception occurred, and a \fIcode\fR argument holding the return
-code value of the exception. The state of the interpreter, including
-any error message in the interpreter result, and the values of
-any entries in the return options dictionary, is captured and
-saved. \fBTcl_BackgroundException\fR then arranges for the event
-loop to invoke at some later time the command registered
-in that interpreter to handle background errors by the
-\fBinterp bgerror\fR command, passing the captured values as
-arguments.
-The registered handler command is meant to report the exception
-in an application-specific fashion. The handler command
-receives two arguments, the result of the interp, and the
-return options of the interp at the time the error occurred.
-If the application registers no handler command, the default
-handler command will attempt to call \fBbgerror\fR to report
-the error. If an error condition arises while invoking the
-handler command, then \fBTcl_BackgroundException\fR reports the
-error itself by printing a message on the standard error file.
-.PP
-\fBTcl_BackgroundException\fR does not invoke the handler command immediately
-because this could potentially interfere with scripts that are in process
-at the time the error occurred.
-Instead, it invokes the handler command later as an idle callback.
-.PP
-It is possible for many background exceptions to accumulate before
-the handler command is invoked. When this happens, each of the exceptions
-is processed in order. However, if the handler command returns a
-break exception, then all remaining error reports for the
-interpreter are skipped.
-.PP
-The \fBTcl_BackgroundError\fR routine is an older and simpler interface
-useful when the exception code reported is \fBTCL_ERROR\fR. It is
-equivalent to:
-.PP
-.CS
-Tcl_BackgroundException(interp, TCL_ERROR);
-.CE
-
-.SH KEYWORDS
-background, bgerror, error, interp
OSDN Git Service
