# Getopt::Simple - perldoc - [phpMan]

## NAME
    "[Getopt::Simple](https://www.chedong.com/phpMan.php/perldoc/Getopt%3A%3ASimple/markdown)" - Provide a simple wrapper around [Getopt::Long](https://www.chedong.com/phpMan.php/perldoc/Getopt%3A%3ALong/markdown).

## SYNOPSIS
            use [Getopt::Simple](https://www.chedong.com/phpMan.php/perldoc/Getopt%3A%3ASimple/markdown);

            # Or ...
            # use [Getopt::Simple](https://www.chedong.com/phpMan.php/perldoc/Getopt%3A%3ASimple/markdown) qw($switch);

            my($options) =
            {
            help =>
                    {
                    type    => '',
                    env     => '-',
                    default => '',
    #               verbose => '',      # Not needed on every key.
                    order   => 1,
                    },
            username =>
                    {
                    type    => '=s',    # As per [Getopt::Long](https://www.chedong.com/phpMan.php/perldoc/Getopt%3A%3ALong/markdown).
                    env     => '$USER', # Help text.
                    default => $ENV{'USER'} || 'RonSavage', # In case $USER is undef.
                    verbose => 'Specify the username on the remote machine',
                    order   => 3,       # Help text sort order.
                    },
            password =>
                    {
                    type    => '=s',
                    env     => '-',
                    default => 'password',
                    verbose => 'Specify the password on the remote machine',
                    order   => 4,
                    },
            };

            my($option) = [Getopt::Simple](https://www.chedong.com/phpMan.php/perldoc/Getopt%3A%3ASimple/markdown) -> new();

            if (! $option -> getOptions($options, "Usage: testSimple.pl [options]") )
            {
                    exit(-1);       # Failure.
            }

            print "username: $$option{'switch'}{'username'}. \n";
            print "password: $$option{'switch'}{'password'}. \n";

            # Or, after 'use [Getopt::Simple](https://www.chedong.com/phpMan.php/perldoc/Getopt%3A%3ASimple/markdown) qw($switch);' ...
            # print "username: $$switch{'username'}. \n";
            # print "password: $$switch{'password'}. \n";

## DESCRIPTION
    "[Getopt::Simple](https://www.chedong.com/phpMan.php/perldoc/Getopt%3A%3ASimple/markdown)" is a pure Perl module.

    The "[Getopt::Simple](https://www.chedong.com/phpMan.php/perldoc/Getopt%3A%3ASimple/markdown)" module provides a simple way of specifying:

    *   Command line switches

    *   Type information for switch values

    *   Default values for the switches

    *   Help text per switch

## Distributions
    This module is available both as a Unix-style distro (*.tgz) and an ActiveState-style distro
    (*.ppd). The latter is shipped in a *.zip file.

    See <http://savage.net.au/Perl-modules.html> for details.

    See <http://savage.net.au/Perl-modules/html/installing-a-module.html> for help on unpacking and
    installing each type of distro.

## Constructor and initialization
### new

    This is the class's contructor.

    Usage: [Getopt::Simple](https://www.chedong.com/phpMan.php/perldoc/Getopt%3A%3ASimple/markdown) -> new().

    This method does not take any parameters.

## The dumpOptions() function
### dumpOptions

### dumpOptions

## The getOptions() function
    The getOptions() function takes 4 parameters:

    *   A hash ref defining the command line switches

        The structure of this hash ref is defined in the next section.

        This parameter is mandatory.

    *   A string to display as a help text heading

        This parameter is mandatory.

    *   A Boolean. 0 = (Default) Use case-sensitive switch names. 1 = Ignore case

        This parameter is optional.

    *   A Boolean. 0 = Return after displaying help. 1 = (Default) Terminate with [exit(0)](https://www.chedong.com/phpMan.php/man/exit/0/markdown) after
        displaying help

        This parameter is optional.

### getOptions

## The hash ref of command line switches
    *   Each key in the hash ref is the name of a command line switch

    *   Each key points to a hash ref which defines the nature of that command line switch

        The keys and values of this nested hash ref are as follows.

        *   default => 'Some value'

            This key, value pair is mandatory.

            This is the default value for this switch.

            Examples:

                    default => '/users/home/dir'
                    default => $ENV{'REMOTEHOST'} || '127.0.0.1'

        *   env => '-' || 'Some short help text'

            This key, value pair is mandatory.

            This is help test, to indicate that the calling program can use an environment variable
            to set the default value of this switch.

            Use '-' to indicate that no environment variable is used.

            Examples:

                    env => '-'
                    env => '$REMOTEHOST'

            Note the use of ' to indicate we want the $ to appear in the output.

        *   type => 'Types as per [Getopt::Long](https://www.chedong.com/phpMan.php/perldoc/Getopt%3A%3ALong/markdown)'

            This key, value pair is mandatory.

            This is the type of the command line switch, as defined by [Getopt::Long](https://www.chedong.com/phpMan.php/perldoc/Getopt%3A%3ALong/markdown).

            Examples:

                    type => '=s'
                    type => '=s@',

        *   verbose => 'Some long help text'

            This key, value pair is optional.

            This is long, explanatory help text which is displayed below the help containing the
            three columns of text: switch name, env value, default value.

            Examples:

                    verbose => 'Specify the username on the remote machine',
                    verbose => 'Specify the home directory on the remote machine'

        *   order => \d+

            This key, value pair is mandatory.

            This is the sort order used to force the help text to display the switches in a specific
            order down the page.

            Examples:

                    order => 1
                    order => 9

## The helpOptions() function
### helpOptions

### helpOptions

The $$classRef{'switch'} hash reference
    Command line option values are accessed in your code by dereferencing the hash reference
    $$classRef{'switch'}. Two examples are given above, under synopsis.

    Alternately, you can use the hash reference $switch. See below.

The $switch hash reference
    Command line option values are accessed in your code by dereferencing the hash reference
    $switch. Two examples are given above, under synopsis.

    Alternately, you can use the hash reference $$classRef{'switch'}. See above.

WARNING re Perl bug
    As always, be aware that these 2 lines mean the same thing, sometimes:

    *   $self -> {'thing'}

    *   $self->{'thing'}

    The problem is the spaces around the ->. Inside double quotes, "...", the first space stops the
    dereference taking place. Outside double quotes the scanner correctly associates the $self token
    with the {'thing'} token.

    I regard this as a bug.

## AUTHOR
    "[Getopt::Simple](https://www.chedong.com/phpMan.php/perldoc/Getopt%3A%3ASimple/markdown)" was written by Ron Savage *<<ron@savage.net.au>>* in 1997.

## LICENCE
    Australian copyright (c) 1997-2002 Ron Savage.

            All Programs of mine are 'OSI Certified Open Source Software';
            you can redistribute them and/or modify them under the terms of
            The Artistic License, a copy of which is available at:
            <http://www.opensource.org/licenses/index.html>

