gistfile1.rb

UNESCAPES = {
    'a' => "\x07", 'b' => "\x08", 't' => "\x09",
    'n' => "\x0a", 'v' => "\x0b", 'f' => "\x0c",
    'r' => "\x0d", 'e' => "\x1b", "\\\\" => "\x5c",
    "\"" => "\x22", "'" => "\x27"
}

puts UNESCAPES.keys.join
#exit

def unescape_literal(str)
  # Escape all the things
  str.gsub(/\\(?:([#{UNESCAPES.keys.join}])|u([\da-fA-F]{4}))|\\0?x([\da-fA-F]{2})/) {
    if $1
      if $1 == '\\' then '\\' else UNESCAPES[$1] end
    elsif $2 # escape \u0000 unicode
      ["#$2".hex].pack('U*')
    elsif $3 # escape \0xff or \xff
      [$3].pack('H2')
    end
  }
end

# Parse a command line style list of arguments that can be optionally
# delimited by '' or "" quotes, and return it as an array of arguments.
#
# Strings delimited by "" are unescaped by converting escape characters
# such as \n \x.. to their value according to the unescape_literal() function.
#
# Example of line that this function can parse:
#
# "Hello World\n" other arguments 'this is a single argument'
#
# The above example will return an array of four strings.
def unescape_line(line)
    argv = []
    arg = ""
    inquotes = false
    pos = 0
    while pos < line.length
        char = line[pos..pos] # Current character
        isspace = char =~ /\s/

        # Skip empty spaces if we are between strings
        if !inquotes && isspace
            if arg.length != 0
                argv << arg
                arg = ""
            end
            pos += 1
            next
        end

        # Append current char to string
        arg << char
        pos += 1

        if arg.length == 1 && (char == '"' || char == '\'')
            inquotes = char
        elsif arg.length > 1 && inquotes && char == inquotes
            inquotes = false
        end
    end
    # Put the last argument into the array
    argv << arg if arg.length != 0

    # We need to make some post-processing.
    # For strings delimited by '' we just strip initial and final '.
    # For strings delimited by "" we call unescape_literal().
    # This is not perfect but should be enough for redis.io interactive
    # editing.
    argv.map {|x|
        if x[0..0] == '"'
            unescape_literal(x[1..-2])
        elsif x[0..0] == '\''
            x[1..-2]
        else
            x
        end
    }
end

while true
    print "prompt> "
    STDOUT.flush
    line = STDIN.gets
    puts unescape_line(line).join(",")
end