ARGS
Command Line Argument Retrieval


ARGS is a MATLAB program which demonstrates command line argument retrieval.

In particular, ARGS is a demonstration of the NARGIN function, which counts command line arguments and the VARARGIN function, which allows the user to specify that a routine has a variable number of input arguments.

If a MATLAB function takes input arguments, such as

        function value = summer ( alpha, beta )
      
then there are two ways of supplying some or all the argument values when invoking the function.

We can call with commandline arguments:

        value = summer
        or
        value = summer 2
        or
        value = summer 2 4
      
or with functional arguments:
        value = summer ( )
        or
        value = summer ( 2 )
        or
        value = summer ( 2, 4 )
      
as long as the arguments are processed correctly.

In the commandline form, the arguments will be given to the function as character strings, which must be re-interpreted as numbers. A convenient way to allow the user to use either way of invoking the function requires that the function include a check as to the type of value it has been given. For example, to handle ALPHA, we might write

        if ( nargin < 1 )
          alpha = input ( 'Enter value of alpha: ' );
        elseif ( ischar ( alpha ) )
          alpha = str2num ( alpha );
        end
      

Licensing:

The computer code and data files made available on this web page are distributed under the GNU LGPL license.

Languages:

ARGS is available in a C version and a C++ version and a FORTRAN77 version and a FORTRAN90 version and a JAVA version and a MATLAB version.

Source Code:

Examples and Tests:

You can go up one level to the MATLAB source codes.


Last revised on 21 April 2013.