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Sagar R. Shah > Getopt-CallingName-1.18 > Getopt::CallingName



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Module Version: 1.18   Source  


Getopt::CallingName - Script duties delegation based upon calling name


 use Getopt::CallingName;
           name_prefix => 'tv_',
           args        => \@my_array,


Sometimes you can have a script that can run in two or more 'modes' of operation. Apart from an option to specify the mode, the command line options are the same/very similar. Much of the code used by the various modes is common.

As an application user interface decision, it may be more useful/helpful to be able to call the script by two or more names - i.e. one for each mode. This cuts out the command line option for specifying the mode.

In some cases it might be appropriate just to move all the code, or at least all the common code, into a module and have separate wrapper perl scripts. The problem with this approach is either you end up duplicating command line option handling in each of the wrapper scripts or you end up moving the command line option handling into a module also. The former case introduces maintenance burden [or perhaps an excuse to use TT2 to generate your wrappers ;-)]. The latter case can feel like a distortion/displacement of the code.

Getopt::CallingName provides another alternative. The idea is that you create symbolic links to your actual script (which you might want to give a generic name). Each symbolic link corresponds to the name/mode with which you call the script. Within your script, after any common setup/options handling you call subroutine call_name to call the appropriate script subroutine for the mode.


Public Class Methods


            args          => $ra_args,
            name_prefix   => $name_prefix,
            method_prefix => $method_prefix,
            method_suffix => $method_suffix,

call_name accepts the following optional arguments:

  method_prefix - string to prepend to the calculated method name

  method_suffix - string to append to the calculated method name

  name_prefix - string to chop off the front  of the script name when calculating
               the method  name.  Useful if all  your  modes have a common
               prefix (tv_record, tv_play ...)

  args         - reference to an array which should be passed to the called sub.

call_name returns whatever the called subroutine returns.

call_name checks the subroutine it is going to call to ensure it exists. If it does not exist, call name throws an 'exception' using Carp::croak.


Private Class Methods


            name_prefix   => $name_prefix,
            method_prefix => $method_prefix,
            method_suffix => $method_suffix,

Returns the $PROGRAM_NAME after removing any path, prefix (optional) and extension. Adds and optional method prefix and/or suffix as specified.


To install this module type the following:

   perl Makefile.PL
   make test
   make install


This module works only with perl v5.6 and higher. I am more than happy to backport to an earlier perl 5.x if someone using an old perl would like to make use of my module. Mail me and ask me to do the work [or even better do it yourself and send in a patch! ;-)]

This module requires these other modules and libraries:


The first is required for its operation. The second is for testing purposes

This module has these optional dependencies:

 Test::Pod (0.95 or higher)

These are both just requried for testing purposes.



None known at time of writing. To report a bug or request an enhancement use CPAN's excellent Request Tracker:


This source is part of a SourceForge project which always has the latest sources in svn.


Sagar R. Shah


Copyright 2003-2007, Sagar R. Shah, All rights reserved

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

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