error - Generate an error
error message ?info? ?code?
error(1t) Tcl Built-In Commands error(1t)
______________________________________________________________________________
NAME
error - Generate an error
SYNOPSIS
error message ?info? ?code?
______________________________________________________________________________
DESCRIPTION
Returns a TCL_ERROR code, which causes command interpretation to be
unwound. Message is a string that is returned to the application to
indicate what went wrong.
The -errorinfo 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 -errorinfo
return option. If the info argument is present, it is used to initial-
ize the -errorinfo return options and the first increment of unwind
information will not be added by the Tcl interpreter. In other words,
the command containing the error command will not appear in the stack
trace; in its place will be info. Historically, this feature had been
most useful in conjunction with the catch command: if a caught error
cannot be handled successfully, info can be used to return a stack
trace reflecting the original point of occurrence of the error:
catch {...} errMsg
set savedInfo $::errorInfo
...
error $errMsg $savedInfo
When working with Tcl 8.5 or later, the following code should be used
instead:
catch {...} errMsg options
...
return -options $options $errMsg
If the code argument is present, then its value is stored in the
-errorcode return option. The -errorcode return option is intended to
hold a machine-readable description of the error in cases where such
information is available; see the return manual page for information on
the proper format for this option's value.
EXAMPLE
Generate an error if a basic mathematical operation fails:
if {1+2 != 3} {
error "something is very wrong with addition"
}
ATTRIBUTES
See attributes(7) for descriptions of the following attributes:
+---------------+------------------+
|ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+---------------+------------------+
|Availability | runtime/tcl-8 |
+---------------+------------------+
|Stability | Uncommitted |
+---------------+------------------+
SEE ALSO
catch(n), return(n)
KEYWORDS
error, exception
NOTES
Source code for open source software components in Oracle Solaris can
be found at https://www.oracle.com/downloads/opensource/solaris-source-
code-downloads.html.
This software was built from source available at
https://github.com/oracle/solaris-userland. The original community
source was downloaded from http://prdownloads.sourceforge.net/tcl/tcl-
core8.6.7-src.tar.gz.
Further information about this software can be found on the open source
community website at https://www.tcl.tk/.
Tcl error(1t)