Tcl_WrongNumArgs(3) Tcl Library Procedures Tcl_WrongNumArgs(3)
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NAME
Tcl_WrongNumArgs - generate standard error message for wrong number of arguments
SYNOPSIS
#include <tcl.h>
Tcl_WrongNumArgs(interp, objc, objv, message)
ARGUMENTS
Tcl_Interp interp (in) Interpreter in which error will be reported: error message
gets stored in its result object.
int objc (in) Number of leading arguments from objv to include in error mes-sage. message.
sage.
Tcl_Obj *CONST objv[] (in) Arguments to command that had the wrong number of arguments.
CONST char *message (in) Additional error information to print after leading arguments
from objv. This typically gives the acceptable syntax of the
command. This argument may be NULL.
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DESCRIPTION
Tcl_WrongNumArgs is a utility procedure that is invoked by command procedures when they discover that
they have received the wrong number of arguments. Tcl_WrongNumArgs generates a standard error mes-sage message
sage and stores it in the result object of interp. The message includes the objc initial elements of
objv plus message. For example, if objv consists of the values foo and bar, objc is 1, and message
is ``fileName count'' then interp's result object will be set to the following string:
wrong # args: should be "foo fileName count"
If objc is 2, the result will be set to the following string:
wrong # args: should be "foo bar fileName count"
Objc is usually 1, but may be 2 or more for commands like string and the Tk widget commands, which
use the first argument as a subcommand.
Some of the objects in the objv array may be abbreviations for a subcommand. The command
Tcl_GetIndexFromObj will convert the abbreviated string object into an indexObject. If an error
occurs in the parsing of the subcommand we would like to use the full subcommand name rather than the
abbreviation. If the Tcl_WrongNumArgs command finds any indexObjects in the objv array it will use
the full subcommand name in the error message instead of the abbreviated name that was originally
passed in. Using the above example, lets assume that bar is actually an abbreviation for barfly and
the object is now an indexObject because it was passed to Tcl_GetIndexFromObj. In this case the
error message would be:
wrong # args: should be "foo barfly fileName count"
SEE ALSO
Tcl_GetIndexFromObj
KEYWORDS
command, error message, wrong number of arguments
Tcl 8.0 Tcl_WrongNumArgs(3)
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