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 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 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, let us 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