# 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]
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 shellsplit(line)
words = []
field = String.new
line.scan(/\G\s*(?>([^\s\\\'\"]+)|'([^\']*)'|"((?:[^\"\\]|\\.)*)"|(\\.?)|(\S))(\s|\z)?/m) do
|word, sq, dq, esc, garbage, sep|
raise ArgumentError, "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>
field << (word || sq || (dq && dq.gsub(/\\([$`"\\\n])/, '\\1')) || esc.gsub(/\\(.)/, '\\1'))
if sep
words << field
field = String.new
end
end
words
end
alias shellwords shellsplit
module_function :shellsplit, :shellwords
class << self
alias split shellsplit
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 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.gsub!(/[^A-Za-z0-9_\-.,:+\/@\n]/, "\\\\\\&")
# A LF cannot be escaped with a backslash because a backslash + LF
# combo is regarded as a line continuation and simply ignored.
str.gsub!(/\n/, "'\n'")
return str
end
module_function :shellescape
class << self
alias escape shellescape
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 shelljoin(array)
array.map { |arg| shellescape(arg) }.join(' ')
end
module_function :shelljoin
class << self
alias join shelljoin
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
