Data::CTable::Script - CTable virtual subclass to support shell scripts


        ## Call from a shell script:
        use      Data::CTable::Script;
        exit    !Data::CTable::Script->script();

        ## But more likely, you'll want to subclass first:
        use      Data::CTable::MyScript;
        exit    !Data::CTable::MyScript->script();

This is an OO implementation of the outermost structure and utlility routines that would be needed by most any perl/shell script that wants to use Data::CTable functionality.

See Data::CTable::Lister for a sample subclass that uses this superstructure to implement a command-line tool that makes a table containing file listings and then lets the user manipulate it using various command-line options and then output it in various interesting ways.

See Data::CTable for the superclass.


See the Data::CTable home page:


Chris Thorman <>

Copyright (c) 1995-2002 Chris Thorman. All rights reserved.

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


        $Class->usage()                     ## Don't subclass
        $Class->usage_message($ScriptName)  ## Subclass this

usage() figures out the name of the script being called and passes it to usage_message (designed to be sublcassed), which can the print the message including the name of the script.


Specification for command-line option parsing for the script. Meant to be subclassed.

Should return a hash mapping GetOpt::Long-style specifications to default values. This base class implementation returns the following spec entries. Subclasses could replace these entirely or add to them:

        ## Common options
        "help"                  =>      0 ,
        "verbose"               =>      0 ,
        ## Which fields are included in output
        "fields=s"              =>      [],
        ## Sorting
        "sort=s"                =>      [],
        ## Output method
        "output=s"              =>      [],

In the above specs "=s" means a string argument, and [] means multiple values are allowed and will be collected in an array, whose initial contents are empty. 0 means the option defaults to off; a default of foo => 1 would allow the --nofoo switch to turn off the foo option.


Class method: main entry point for the script. Parses options, presents usage(), instantiates an object and lets it do its work. Returns a Boolean success value. (A perl script should exit() the opposite of this value: i.e. exit(0) means success.)


Main entry point for the script. Instantiates an object and lets it do its work. Returns a reference to a scalar which will be printed before the script exits. (Pass \ '' for no output).


Internal method to process command-line options using GetOpt::Long and a few enhancements, most importantly: any multi-valued field is post-processed to treat any values separated by commas or spaces as multiple values.