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Tcl_WrongNumArgs(3tcl) Tcl Library Procedures Tcl_WrongNumArgs(3tcl) 





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 value.

  
Tcl_Size objc (in)

  
Number of leading arguments from objv to include in error
    message.

  
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.
    
    

    

  








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
    message and stores it in the result value 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 value 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 values in the objv array may be abbreviations
    for a subcommand. The command Tcl_GetIndexFromObj will convert the
    abbreviated string value 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, let us assume that
    bar is actually an abbreviation for barfly and the value 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"








REFERENCE COUNT MANAGEMENT


The objv argument to Tcl_WrongNumArgs should be the
    exact arguments passed to the command or method implementation function that
    is calling Tcl_WrongNumArgs. As such, all values referenced in it
    should have reference counts greater than zero; this is usually a
  non-issue.






SEE ALSO


Tcl_GetIndexFromObj(3tcl)






KEYWORDS


command, error message, wrong number of arguments







  

    8.0
    Tcl