error(n)						       Tcl Built-In Commands							  error(n)

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NAME

       error - Generate an error

SYNOPSIS

       error message ?info? ?code?
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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 initialize 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"
	      }

SEE ALSO

       catch(n), return(n)

KEYWORDS

       error

Tcl																	  error(n)