# Converted from openEuler /usr/share/ruby/shellwords.rb
# Upstream ruby code is accessible at
# https://github.com/ruby/ruby/blob/master/lib/shellwords.rb
#
# Copyright (C) 1993-2013 Yukihiro Matsumoto. All rights reserved.
#
# Redistribution and use in source and binary forms, with or without
# modification, are permitted provided that the following conditions
# are met:
# 1. Redistributions of source code must retain the above copyright
#    notice, this list of conditions and the following disclaimer.
# 2. Redistributions in binary form must reproduce the above copyright
#    notice, this list of conditions and the following disclaimer in the
#    documentation and/or other materials provided with the distribution.
#
# THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
# ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
# ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
# OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
# OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
# SUCH DAMAGE.
#
# frozen-string-literal: true
##
# == Manipulates strings like the UNIX Bourne shell
#
# This module manipulates strings according to the word parsing rules
# of the UNIX Bourne shell.
#
# The shellwords() function was originally a port of shellwords.pl,
# but modified to conform to the Shell & Utilities volume of the IEEE
# Std 1003.1-2008, 2016 Edition [1].
#
# === Usage
#
# You can use Shellwords to parse a string into a Bourne shell friendly Array.
#
#   require 'shellwords'
#
#   argv = Shellwords.split('three blind "mice"')
#   argv #=> ["three", "blind", "mice"]
#
# Once you've required Shellwords, you can use the #split alias
# String#shellsplit.
#
#   argv = "see how they run".shellsplit
#   argv #=> ["see", "how", "they", "run"]
#
# Be careful you don't leave a quote unmatched.
#
#   argv = "they all ran after the farmer's wife".shellsplit
#        #=> ArgumentError: Unmatched double quote: ...
#
# In this case, you might want to use Shellwords.escape, or its alias
# String#shellescape.
#
# This method will escape the String for you to safely use with a Bourne shell.
#
#   argv = Shellwords.escape("special's.txt")
#   argv #=> "special\\'s.txt"
#   system("cat " + argv)
#
# Shellwords also comes with a core extension for Array, Array#shelljoin.
#
#   argv = %w{ls -lta lib}
#   system(argv.shelljoin)
#
# You can use this method to create an escaped string out of an array of tokens
# separated by a space. In this example we used the literal shortcut for
# Array.new.
#
# === Authors
# * Wakou Aoyama
# * Akinori MUSHA <knu@iDaemons.org>
#
# === Contact
# * Akinori MUSHA <knu@iDaemons.org> (current maintainer)
#
# === Resources
#
# 1: {IEEE Std 1003.1-2008, 2016 Edition, the Shell & Utilities volume}[http://pubs.opengroup.org/onlinepubs/9699919799/utilities/contents.html]
#
# === original comment END <above is come from /usr/share/ruby/shellwords.rb>

module Shellwords
  # Splits a string into an array of tokens in the same way the UNIX
  # Bourne shell does.
  #
  #   argv = Shellwords.split('here are "two words"')
  #   argv #=> ["here", "are", "two words"]
  #
  # Note, however, that this is not a command line parser.  Shell
  # metacharacters except for the single and double quotes and
  # backslash are not treated as such.
  #
  #   argv = Shellwords.split('ruby my_prog.rb | less')
  #   argv #=> ["ruby", "my_prog.rb", "|", "less"]
  #
  # String#shellsplit is a shortcut for this function.
  #
  #   argv = 'here are "two words"'.shellsplit
  #   argv #=> ["here", "are", "two words"]
  def self.shellsplit(line)
    words = Array(String).new
    field = String.new
    line.scan(/\G\s*(?>([^\s\\\'\"]+)|'([^\']*)'|"((?:[^\"\\]|\\.)*)"|(\\.?)|(\S))(\s|\z)?/m) do |m|
      word, sq, dq, esc, garbage, sep = m[1]?, m[2]?, m[3]?, m[4]?, m[5]?, m[6]?

      raise "Unmatched double quote: #{line.inspect}" if garbage
      # 2.2.3 Double-Quotes:
      #
      #   The <backslash> shall retain its special meaning as an
      #   escape character only when followed by one of the following
      #   characters when considered special:
      #
      #   $ ` " \ <newline>
      find = (word || sq || (dq && dq.gsub(/\\([$`"\\\n])/, "\\1")) || (esc && esc.gsub(/\\(.)/, "\\1")))
      field = field + find if find
      if sep
        words  << field
        field = String.new
      end
    end
    words
  end

  def self.shellwords(line)
    shellsplit(line)
  end

  def self.split(line)
    shellsplit(line)
  end

  # Escapes a string so that it can be safely used in a Bourne shell
  # command line.  +str+ can be a non-string object that responds to
  # +to_s+.
  #
  # Note that a resulted string should be used unquoted and is not
  # intended for use in double quotes nor in single quotes.
  #
  #   argv = Shellwords.escape("It's better to give than to receive")
  #   argv #=> "It\\'s\\ better\\ to\\ give\\ than\\ to\\ receive"
  #
  # String#shellescape is a shorthand for this function.
  #
  #   argv = "It's better to give than to receive".shellescape
  #   argv #=> "It\\'s\\ better\\ to\\ give\\ than\\ to\\ receive"
  #
  #   # Search files in lib for method definitions
  #   pattern = "^[ \t]*def "
  #   open("| grep -Ern #{pattern.shellescape} lib") { |grep|
  #     grep.each_line { |line|
  #       file, lineno, matched_line = line.split(':', 3)
  #       # ...
  #     }
  #   }
  #
  # It is the caller's responsibility to encode the string in the right
  # encoding for the shell environment where this string is used.
  #
  # Multibyte characters are treated as multibyte characters, not as bytes.
  #
  # Returns an empty quoted String if +str+ has a length of zero.
  def self.shellescape(str)
    str = str.to_s

    # An empty argument will be skipped, so return empty quotes.
    return "''".dup if str.empty?

    str = str.dup

    # Treat multibyte characters as is.  It is the caller's responsibility
    # to encode the string in the right encoding for the shell
    # environment.
    str = str.gsub(/([^A-Za-z0-9_\-.,:\/@\n])/, "\\\\\\1")

    str = str.gsub(/'/, "\\'")
    str = str.gsub(/ /, "\\ ")

    # A LF cannot be escaped with a backslash because a backslash + LF
    # combo is regarded as a line continuation and simply ignored.
    str = str.gsub(/\n/, "'\\n'")

    return str
  end

  def self.escape(str)
    shellescape(str)
  end

  # Builds a command line string from an argument list, +array+.
  #
  # All elements are joined into a single string with fields separated by a
  # space, where each element is escaped for the Bourne shell and stringified
  # using +to_s+.
  #
  #   ary = ["There's", "a", "time", "and", "place", "for", "everything"]
  #   argv = Shellwords.join(ary)
  #   argv #=> "There\\'s a time and place for everything"
  #
  # Array#shelljoin is a shortcut for this function.
  #
  #   ary = ["Don't", "rock", "the", "boat"]
  #   argv = ary.shelljoin
  #   argv #=> "Don\\'t rock the boat"
  #
  # You can also mix non-string objects in the elements as allowed in Array#join.
  #
  #   output = `#{['ps', '-p', $$].shelljoin}`
  #
  def self.shelljoin(array)
    array.map { |arg| shellescape(arg) }.join(' ')
  end

  def self.join(array)
    shelljoin(array)
  end
end

class String
  # call-seq:
  #   str.shellsplit => array
  #
  # Splits +str+ into an array of tokens in the same way the UNIX
  # Bourne shell does.
  #
  # See Shellwords.shellsplit for details.
  def shellsplit
    Shellwords.split(self)
  end

  # call-seq:
  #   str.shellescape => string
  #
  # Escapes +str+ so that it can be safely used in a Bourne shell
  # command line.
  #
  # See Shellwords.shellescape for details.
  def shellescape
    Shellwords.escape(self)
  end
end

class Array
  # call-seq:
  #   array.shelljoin => string
  #
  # Builds a command line string from an argument list +array+ joining
  # all elements escaped for the Bourne shell and separated by a space.
  #
  # See Shellwords.shelljoin for details.
  def shelljoin
    Shellwords.join(self)
  end
end

# crystal test case
#puts Shellwords.shellsplit("three blind \"mice\"")
# => ["three", "blind", "mice"]
#puts  Shellwords.shellsplit("see how they run")
# => ["see", "how", "they", "run"]
#puts  Shellwords.shellsplit("they all ran after the farmer's wife")
# => Unhandled exception
#puts  Shellwords.shellsplit("here are \"two words\"")
# => ["here", "are", "two words"]
#puts  Shellwords.shellwords("ruby my_prog.rb | less")
# => ["ruby", "my_prog.rb", "|", "less"]

#puts Shellwords.shellescape("special's.txt")
# => special\\'s.txt
#puts Shellwords.shellescape("It's better to give than to receive")
# => It\\'s\\ better\\ to\\ give\\ than\\ to\\ receive
#puts Shellwords.shellescape(nil)
# =>  ''
#puts Shellwords.shellescape("test\n")
# => test'\n'

# ary = ["There's", "a", "time", "and", "place", "for", "everything"]
# argv = Shellwords.shelljoin(ary)
#p argv #=> "There\\\\'s a time and place for everything"
#puts argv #=> "There\\'s a time and place for everything"

# ary = ["Don't", "rock", "the", "boat"]
# argv = ary.shelljoin
# argv #=> "Don\\'t rock the boat"

# $$ is ruby current process id. crystal do not has this global name
# output = `#{["ps", "-p", "$$"].shelljoin}`
#  output = `#{['ps', '-p', $$].shelljoin}`

