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Tcl Error Command

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Tcl has no default implementation for bgerror. This variable is intended to hold a machine-readable description of the error in cases where such information is available; see the tclvars manual page for information on the proper format for When a Tcl command or procedure encounters an error during its execution, the global variable errorInfo is set, and an error condition is generated. throw }There is no throw command in Tcl [editors note: Of course there is one nowadays], so it is handled by unknown, which tries to load it from auto_index, and if have a peek here

When the return code from the script is 0 (TCL_OK), the value stored in resultVarName is the value returned from script. DESCRIPTION Returns a TCL_ERROR code, which causes command interpretation to be unwound. However, in applications using Tk there is a default bgerror procedure which posts a dialog box containing the error message and offers the user a chance to see a stack trace 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 More hints

Tcl Error Python

wiki.tcl.tk error Updated 2016-10-02 07:45:53 by dkf ▲ error, a built-in Tcl command, triggers an error state. error message ?info? ?code? return (2) The return code of the procedure is 2 (TCL_RETURN).

In C, you would have received a NULL pointer, and without checking that, Segmentation Fault would be right around the corner. In either case, a message will be placed in errorInfo, and the proc will generate an error. If supplied, info is used to seed the errorInfo value, and code becomes the errorCode, which is otherwise NONE.error is short for return -level 0 -code error, which is not the Tcl Throw Error EXAMPLE Generate an error if a basic mathematical operation fails: if {1+2 != 3} { error "something is very wrong with addition" } SEE ALSO catch, return, tclvars KEYWORDS error, errorCode,

DESCRIPTION EXCEPTIONAL RETURN CODES ok (or 0) error (1) return (2) break (3) continue (4) value EXAMPLES SEE ALSO KEYWORDS NAME return - Return from a procedure SYNOPSIS return ?-code code? Tcl Error Handling 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 However, the -code option may be used to generate an exceptional return from the procedure. http://wiki.tcl.tk/error If another Tcl error occurs within the bgerror command (for example, because no bgerror command has been defined) then Tcl reports the error itself by writing a message to stderr.

If the info argument is provided and is non-empty, it is used to initialize the global variable errorInfo. Tcl Warning return -options $options $errMsg If the code argument is present, then its value is stored in the -errorcode return option. When the catch statement is compiled, the script is compiled as well and any syntax errors will generate a Tcl error. When a background error occurs, the unwinding ends in the Tcl library and there is no obvious way for Tcl to report the error.

Tcl Error Handling

The catch command returns 0 if there is no error, and 1 if there is an error. https://www.tcl.tk/man/tcl8.4/TclCmd/error.htm Copyright © 1994-1996 Sun Microsystems, Inc. Tcl Error Python error (1) Error return: the return code of the procedure is 1 (TCL_ERROR). Tcl Return Error EXAMPLE This bgerror procedure appends errors to a file, with a timestamp.

The procedure command behaves in its calling context as if it were the command error result. navigate here The procedure command behaves in its calling context as if it were the command break. When in doubt, just use error.Show discussionDKF: I find that it is best to use error (or throw) when it is an internal problem of the code, and return -code error If not, the error is placed in varName. Tcl Error Code

Generates an error condition and forces the Tcl call stack to unwind, with error information being added at each step. When Tcl detects a background error, it saves information about the error and invokes the bgerror command later as an idle event handler. 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 Check This Out NAME bgerror - Command invoked to process background errors SYNOPSIS bgerror message DESCRIPTION The bgerror command doesn't exist as built-in part of Tcl.

break (3) The return code of the procedure is 3 (TCL_BREAK). Errorinfo Tcl Note that catch catches all exceptions, including those generated by break and continue as well as errors. The procedure command behaves in its calling context as if it were the command continue.

The other exceptional return codes are returned by the return, break, and continue commands and in other special situations as documented.

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Typically the info value is supplied from the value left in errorInfo after a catch command trapped an error within the procedure. 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 Copyright © 1994-1996 Sun Microsystems, Inc. this contact form 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

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