diff options
Diffstat (limited to 'doc/error.n')
| -rw-r--r-- | doc/error.n | 36 |
1 files changed, 20 insertions, 16 deletions
diff --git a/doc/error.n b/doc/error.n index 20bdbfe..c05f8b9 100644 --- a/doc/error.n +++ b/doc/error.n @@ -4,11 +4,9 @@ '\" '\" See the file "license.terms" for information on usage and redistribution '\" of this file, and for a DISCLAIMER OF ALL WARRANTIES. -'\" -'\" RCS: @(#) $Id: error.n,v 1.9 2005/05/10 18:33:59 kennykb Exp $ -'\" -.so man.macros +'\" .TH error n "" Tcl "Tcl Built-In Commands" +.so man.macros .BS '\" Note: do not modify the .SH NAME line immediately below! .SH NAME @@ -23,14 +21,14 @@ Returns a \fBTCL_ERROR\fR code, which causes command interpretation to be unwound. \fIMessage\fR is a string that is returned to the application to indicate what went wrong. .PP -The \fB-errorinfo\fR return option of an interpreter is used +The \fB\-errorinfo\fR return option of an interpreter is used to accumulate a stack trace of what was in progress when an error occurred; as nested commands unwind, -the Tcl interpreter adds information to the \fB-errorinfo\fR +the Tcl interpreter adds information to the \fB\-errorinfo\fR return option. If the \fIinfo\fR argument is present, it is -used to initialize the \fB-errorinfo\fR return options and +used to initialize the \fB\-errorinfo\fR return options and the first increment of unwind information -will not be added by the Tcl interpreter. +will not be added by the Tcl interpreter. In other words, the command containing the \fBerror\fR command will not appear in the stack trace; in its place will be \fIinfo\fR. @@ -39,36 +37,42 @@ with the \fBcatch\fR command: if a caught error cannot be handled successfully, \fIinfo\fR can be used to return a stack trace reflecting the original point of occurrence of the error: +.PP .CS -\fBcatch {...} errMsg +catch {...} errMsg set savedInfo $::errorInfo \&... -error $errMsg $savedInfo\fR +\fBerror\fR $errMsg $savedInfo .CE +.PP When working with Tcl 8.5 or later, the following code should be used instead: +.PP .CS -\fBcatch {...} errMsg options +catch {...} errMsg options \&... -return -options $options $errMsg\fR +return -options $options $errMsg .CE .PP If the \fIcode\fR argument is present, then its value is stored -in the \fB-errorcode\fR return option. The \fB-errorcode\fR +in the \fB\-errorcode\fR return option. The \fB\-errorcode\fR return option is intended to hold a machine-readable description of the error in cases where such information is available; see the \fBreturn\fR manual page for information on the proper format for this option's value. .SH EXAMPLE +.PP Generate an error if a basic mathematical operation fails: +.PP .CS if {1+2 != 3} { \fBerror\fR "something is very wrong with addition" } .CE - .SH "SEE ALSO" catch(n), return(n) - .SH KEYWORDS -error +error, exception +'\" Local Variables: +'\" mode: nroff +'\" End: |