FreeBSD Manual Pages
Tcl_Cancel(3) Tcl Library Procedures Tcl_Cancel(3) ________________________________________________________________________________ NAME Tcl_CancelEval, Tcl_Canceled - cancel Tcl scripts SYNOPSIS #include <tcl.h> int Tcl_CancelEval(interp, resultObjPtr, clientData, flags) int Tcl_Canceled(interp, flags) ARGUMENTS Tcl_Interp *interp (in) Interpreter in which to cancel the script. Tcl_Obj *resultObjPtr (in) Error message to use in the cancellation, or NULL to use a default message. If not NULL, this object will have its reference count decremented before Tcl_CancelEval returns. int flags (in) OR'ed combination of flag bits that spec- ify additional options. For Tcl_CancelE- val, only TCL_CANCEL_UNWIND is currently supported. For Tcl_Canceled, only TCL_LEAVE_ERR_MSG and TCL_CANCEL_UNWIND are currently supported. ClientData clientData (in) Currently reserved for future use. It should be set to NULL. ________________________________________________________________________________ DESCRIPTION Tcl_CancelEval cancels or unwinds the script in progress soon after the next invocation of asynchronous handlers, causing TCL_ERROR to be the re- turn code for that script. This function is thread-safe and may be called from any thread in the process. Tcl_Canceled checks if the script in progress has been canceled and returns TCL_ERROR if it has. Otherwise, TCL_OK is returned. Extensions can use this function to check to see if they should abort a long running command. This function is thread sensitive and may only be called from the thread the interpreter was created in. FLAG BITS Any OR'ed combination of the following values may be used for the flags ar- gument to procedures such as Tcl_CancelEval: TCL_CANCEL_UNWIND This flag is used by Tcl_CancelEval and Tcl_Canceled. For Tcl_CancelEval, if this flag is set, the script in progress is canceled and the evaluation stack for the interpreter is unwound. For Tcl_Canceled, if this flag is set, the script in progress is considered to be can- celed only if the evaluation stack for the interpreter is being unwound. TCL_LEAVE_ERR_MSG This flag is only used by Tcl_Canceled; it is ignored by other procedures. If an error is returned and this bit is set in flags, then an error message will be left in the interpreter's result, where it can be retrieved with Tcl_GetObjResult or Tcl_GetStringResult. If this flag bit is not set then no error message is left and the interpreter's result will not be modified. SEE ALSO interp(n), Tcl_Eval(3), TIP 285 KEYWORDS cancel, unwind Tcl 8.6 Tcl_Cancel(3)
NAME | SYNOPSIS | ARGUMENTS | DESCRIPTION | SEE ALSO | KEYWORDS
Want to link to this manual page? Use this URL:
<https://man.freebsd.org/cgi/man.cgi?query=Tcl_CancelEval.tcl86&sektion=3&manpath=FreeBSD+Ports+15.1.quarterly>