diff options
Diffstat (limited to 'doc/BackgdErr.3')
| -rw-r--r-- | doc/BackgdErr.3 | 32 |
1 files changed, 18 insertions, 14 deletions
diff --git a/doc/BackgdErr.3 b/doc/BackgdErr.3 index 1ac84c4..315e3b9 100644 --- a/doc/BackgdErr.3 +++ b/doc/BackgdErr.3 @@ -5,7 +5,7 @@ '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. '\" -'\" RCS: @(#) $Id: BackgdErr.3,v 1.3 2000/04/14 23:01:48 hobbs Exp $ +'\" RCS: @(#) $Id: BackgdErr.3,v 1.4 2004/11/20 00:17:31 dgp Exp $ '\" .so man.macros .TH Tcl_BackgroundError 3 7.5 Tcl "Tcl Library Procedures" @@ -34,25 +34,29 @@ In these cases the code calls \fBTcl_BackgroundError\fR with an \fIinterp\fR argument identifying the interpreter in which the error occurred. At the time \fBTcl_BackgroundError\fR is invoked, the interpreter's result is expected to contain an error message. -\fBTcl_BackgroundError\fR will invoke the \fBbgerror\fR -Tcl command to report the error in an application-specific fashion. -If no \fBbgerror\fR command exists, or if it returns with an error condition, -then \fBTcl_BackgroundError\fR reports the error itself by printing -a message on the standard error file. +\fBTcl_BackgroundError\fR will invoke the command registered +in that interpreter to handle background errors by the +\fBinterp bgerror\fR command. +The registered handler command is meant to report the error +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_BackgroundError\fR reports the +error itself by printing a message on the standard error file. .PP -\fBTcl_BackgroundError\fR does not invoke \fBbgerror\fR immediately +\fBTcl_BackgroundError\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 \fBbgerror\fR later as an idle callback. -\fBTcl_BackgroundError\fR saves the values of the \fBerrorInfo\fR and -\fBerrorCode\fR variables and restores these values just before -invoking \fBbgerror\fR. +Instead, it invokes the handler command later as an idle callback. .PP It is possible for many background errors to accumulate before -\fBbgerror\fR is invoked. When this happens, each of the errors -is processed in order. However, if \fBbgerror\fR returns a +the handler command is invoked. When this happens, each of the errors +is processed in order. However, if the handle command returns a break exception, then all remaining error reports for the interpreter are skipped. .SH KEYWORDS -background, bgerror, error +background, bgerror, error, interp |