Module: Bulldog::Util::Shellwords

Defined in:
lib/bulldog/util.rb

Class Method Summary collapse

Class Method Details

.escape(str) ⇒ Object

Escapes a string so that it can be safely used in a Bourne shell command line.

Note that a resulted string should be used unquoted and is not intended for use in double quotes nor in single quotes.

open("| grep #{Shellwords.escape(pattern)} file") { |pipe|
  # ...
}



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# File 'lib/bulldog/util.rb', line 43

def escape(str)
  # An empty argument will be skipped, so return empty quotes.
  return "''" if str.empty?

  str = str.dup

  # Process as a single byte sequence because not all shell
  # implementations are multibyte aware.
  str.gsub!(/([^A-Za-z0-9_\-.,:\/@\n])/n, "\\\\\\1")

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

  return str
end

.join(array) ⇒ Object

Builds a command line string from an argument list array joining all elements escaped for Bourne shell and separated by a space.

open('|' + Shellwords.join(['grep', pattern, *files])) { |pipe|
  # ...
}



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# File 'lib/bulldog/util.rb', line 70

def join(array)
  array.map { |arg| escape(arg) }.join(' ')
end