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Simple command line option parsing for Ruby
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= Description
  Implements a simple Getopt::Std class for command line parsing, as well
  as a Getopt::Long class for more advanced command line parsing.

= Installation

  gem install getopt
   
= Synopsis
== Getopt::Std

  require 'getopt/std'
	
  # Look for -o with argument, and -I and -D boolean arguments
  opt = Getopt::Std.getopts("o:ID")

  if opt["I"]
    # Do something if -I passed
		
  if opt["D"]
    # Do something if -D passed
		
  if opt["o"]
    case opt["o"]
      # blah, blah, blah
    end
  end

== Getopt::Long

  require 'getopt/long'

  opt = Getopt::Long.getopts(
    ["--foo", "-f", Getopt::BOOLEAN],
    ["--bar", "-b", Getopt::REQUIRED]
  )
   
  # Or, to save your fingers some typing:
  #
  # require "getopt/long"
  # include Getopt
  # opt = Long.getopts(
  #    ["--foo", "-f", BOOLEAN],
  #    ["--bar", "-b", REQUIRED]
  # )

  if opt["foo"]
    # Do something if --foo or -f passed

  if opt["b"]
    # Do something if --bar or -b passed

= Class Methods

Std.getopts(switches)

  Takes a series of single character switches that can be accepted on the
  command line.  Those characters followed by a ':' require an argument. The
  rest are considered boolean switches.  Returns a hash, with the switches
  as the key (sans the leading '-').  For boolean switches, the value is
  either true or false.  Switches that were not passed on the command line
  do not appear in the hash.

  In the event that a switch that accepts an argument appears multiple times
  the value for that key becomes an array of values.

Long.getopts(switches)

  Takes an array of switches beginning with "--" followed by one or more
  alphanumeric or hyphen characters, or "-" followed by a single character.
  The type of argument, if any, can be specified as BOOLEAN, OPTIONAL,
  REQUIRED or INCREMENT.

  The array should be in the form:

  # long form, short form (alias), option type
  ["--long", "-l", Getopt::OPTION]

  Note that only the long form is required.  If the short form is not
  specified, it will automatically be set to the first letter of the long
  switch.  If multiple long switches with the same first character are
  listed without short switches, only the first long switch gets the short
  switch alias.

  If the argument type is not specified, the default is BOOLEAN.

  For the truly lazy, you can also pass a string of long switches (with
  no short switches or argument types). 

  See the 'examples' directory for more examples.

= Getopt::Long argument types

REQUIRED
  If the option is specified on the command line, it must be followed by
  a non-blank argument.  This argument cannot be another switch. If this
  switch appears multiple times, the values are collected into an array.

BOOLEAN
  If the option is specified on the command line, its value is set to true.
  It must not be followed by a non-blank argument, excluding other switches.
  Attempting to pass a boolean switch more than once will raise an error.

OPTIONAL
  If the option is specified on the command line, it may or may not accept
  an argument, excluding other valid switches.  If an argument is present,
  it's value is set to that argument.  If an argument is not present, it's
  value is set to nil.

INCREMENT
  If the option is specified on the command line, its value is incremented
  by one for each appearance on the command line, or set to 1 if it appears
  only once.

= Future Plans
  Add support for negatable options so that you can do "--no-foo", for
  example.

  Add support for numeric types, so that you don't have to manually convert
  strings to numbers.

  Allow shortcut characters for the option types, e.g. "?" for BOOLEAN, "+"
  for INCREMENT, etc.

= Known Issues

== Getopt::Std

  You cannot squish switches that require arguments with the argument itself.
  For example, if you do Getopt::Std.getopts("o:ID"), it will not parse
  "-IDohello" properly.  Instead, you must do "-IDo hello".  Or, you can just
  separate the argument, e.g. "-I -D -o hello".

== Getopt::Long

  If you mix and match compressed switches with separate, optional switches
  the optional switch will be set to true instead of nil if it separated
  from the compressed switches.
   
== Reporting Issues

  If you find any other issues, please log them on the project
  page at https://github.com/djberg96/getopt.

= Other Stuff

  Neither class attempts to be POSIX compliant in any way, shape or form.
  And I don't care!

= Notes From the Author

  My main gripe with the getoptlong library currently in the standard library
  is that it doesn't return a hash, yet gives you partial hash behavior.  This
  was both confusing and annoying, since the first thing I do (along with
  everyone else) is collect the results into a hash for later processing.

  My main gripe with the optparse library (also in the standard library) is
  that it treats command line processing like event processing.  It's too
  complex, when 90% of the time all you want to do is slurp the command line
  options into a hash.

  So, I did something utterly novel with this library.  I collected the command
  line options ... (wait for it) ... into a hash!  Then I give that hash to
  you, aliases and all.  I did get some ideas from Perl's Getopt::Long library,
  but this is in no way a port of that module (which supports POSIX parsing, GNU
  parsing, more option types, etc).  My goal was to provide the functionality
  that I felt would cover the vast majority of common cases, yet still provide
  a little extra spice with switch types (REQUIRED, OPTIONAL, etc).

  There are a few extra things I plan to add (see the 'Future Plans' above) but
  I do not plan on this library ever becoming as feature rich as, say, Perl's
  Getopt::Long module.
   
  If you plan to write a full fledged command line application, e.g. you plan
  on implementing a full help system, gobs of command line options and tons of
  switches, consider Jim Freeze's 'commandline' gem.

= Warranty
  This package is provided "as is" and without any express or
  implied warranties, including, without limitation, the implied
  warranties of merchantability and fitness for a particular purpose.

= License
  Artistic 2.0

= Copyright
  (C) 2005-2016, Daniel J. Berger
  All Rights Reserved

= Author
  Daniel J. Berger
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