DZone Snippets: tiny code

Generate short URLs using Ruby

jrobertson (James Robertson) — Thu, 14 Feb 2008 05:00:18 GMT

This Ruby code generates shortened URLs. It has the added feature that it will not allow words to be created accidentally eg. swear words.



#!/usr/bin/ruby



class ShortUrl

  def initialize()

    @chars = ('a'..'z').to_a + ('1'..'9').to_a + ('A'..'Z').to_a

    @array_size = @chars.size

    @h = Hash.new

    @chars.each {|c| @h[c] = '0'}

    vowels = %w(a e i o u A E I O U 4 3 1 0)

    vowels.each {|v| @h[v] = '1'}

    nums = %w(2 5 6 7 8 9)

    nums.each {|n| @h[n] = '2'}

    @count = 0

    @a = Array.new(7, -1)

    @k = 0

  end 



  def iterate_chars(array_size)

    (0..array_size).each {|i| 

      increment_index(@k)

      convert_to_chars()

    }

  end

  

  def convert_to_chars()

    buffer = ''

    @a.each {|i|

      buffer << @chars[i] if i >= 0

    }

    a = buffer.reverse.scan(/./)

    k = a.length  

    if  (k > 1)  

      if ((@h[a[k-2]] + @h[a[k-1]]) != '10')

        puts buffer.reverse 

      end

    else

      puts buffer.reverse

    end

  end



  def get_short_url(count)

    if count >  @array_size

      new_count = count - @array_size

      iterate_chars(@array_size)

      get_short_url(new_count)

    else

      iterate_chars(count)

    end

  end

  

  def increment_a(i)

    if @a[i] < @array_size - 1

      @a[i] = @a[i] + 1

      return i 

    else

      @a[i] = 0

      return i += 1

    end 

  end



  def increment_index(k)

    old_k = k

    k = increment_a(k)

    

    if k != old_k

      increment_index(k)

    else

      k = 0

    end

    k

  end



end



if __FILE__ == $0

  su = ShortUrl.new  

  su.get_short_url(222761)

end

Note: You will most likely see the " `convert_to_chars': stack level too deep (SystemStackError)" error message after around 253950 iterations, I'm presuming this is expected due to the memory constraints of the language. However 253k short urls is enough for linking my website to itself.

tiny.conf

mcandre (Andrew Pennebaker) — Sun, 24 Jun 2007 17:10:03 GMT

// Configuration for tiny.py



config = "tiny.conf"

service = "urltea"

urltea url = "http://urltea.com/api/text/?url="

tinyurl url = "http://tinyurl.com/api-create.php?"

description delimeter = "?"

description = ""

tea.py

mcandre (Andrew Pennebaker) — Fri, 22 Jun 2007 18:54:14 GMT

// Converts long URLs to tiny URLs with URLTea.



#!/usr/bin/env python



__author__="Andrew Pennebaker (andrew.pennebaker@gmail.com)"

__date__="22 Jun 2007"

__copyright__="Copyright 2007 Andrew Pennebaker"

__license__="GPL"

__version__="0.0.1"

__URL__="http://urltea.com/to8"

__credits__="http://tinyurl.com/yswqg3"



import sys, urllib, getopt



CREATE_URL="http://urltea.com/api/text/?url="

COMMENT_DELIMETER="?"



def tiny(url, description=""):

	global CREATE_URL

	global COMMENT_DELIMETER



	try:

		encodedurl=CREATE_URL+urllib.urlencode({"url":url})

		instream=urllib.urlopen(encodedurl)

		tinyurl=instream.read()

		instream.close()



		if len(tinyurl)==0:

			return url



		if len(description)>0:

			tinyurl+=COMMENT_DELIMETER+description



		return tinyurl

	except IOError, e:

		raise "Could not connect."



def usage():

	print "Usage: %s    ..." % (sys.argv[0])

	print "-d|--description "

	print "-h|--help (usage)"



	sys.exit()



def main():

	systemArgs=sys.argv[1:]

	oplist, args=[], []



	comment=""



	try:

		optlist, args=getopt.getopt(systemArgs, "d:h", ["description=", "help"])

	except:

		usage()



	for option, value in optlist:

		if option=="-h" or option=="--help":

			usage()

		elif option=="-d" or option=="--description":

			comment=value



	if len(args)<1:

		usage()



	for u in args:

		print tiny(u, comment)



if __name__=="__main__":

	try:

		main()

	except KeyboardInterrupt, e:

		pass

tiny.py

mcandre (Andrew Pennebaker) — Fri, 22 Jun 2007 18:32:06 GMT



#!/usr/bin/env python



"""Converts long URLs to tiny URLs, with either tinyurl, urltea, or a custom url."""



__author__="Andrew Pennebaker (andrew.pennebaker@gmail.com)"

__date__="22 Jun 2007 - 24 Jun 2007"

__copyright__="Copyright 2007 Andrew Pennebaker"

__license__="GPL"

__version__="0.0.1"

__URL__="http://snippets.dzone.com/posts/show/4195"

__credits__="http://lateral.netmanagers.com.ar/weblog/2007/04/08.html#BB548"



import sys, getopt, urllib



import configreader



def tiny(url, settings):

	try:

		encodedurl=settings["posting url"]+urllib.urlencode({"url":url})

		instream=urllib.urlopen(encodedurl)

		tinyurl=instream.read()

		instream.close()



		if len(tinyurl)==0:

			return url



		if settings["service"]=="urltea" and len(settings["description"])>0:

				tinyurl+=settings["description delimeter"]+settings["description"]



		return tinyurl

	except IOError, e:

		raise "Could not connect."



def usage():

	print "Usage: %s [options]    ..." % (sys.argv[0])

	print "\nDefaults to urlTea unless specified in options or a config file."

	print "\n-s|--service [tinyurl|urltea]"

	print "-u|--custom-url "

	print "-d|--description  May only be used with urltea."

	print "-c|--config "

	print "-h|--help (usage)"



	sys.exit()



def main():

	systemArgs=sys.argv[1:]

	oplist, args=[], []



	settings={

		"config":"tiny.conf",

		"service":"urltea",

		"urltea url":"http://urltea.com/api/text/?url=",

		"tinyurl url":"http://tinyurl.com/api-create.php?",

		"description delimeter":"?",

		"description":""

	}



	try:

		optlist, args=getopt.getopt(systemArgs, "s:u:d:c:h", ["service=", "custom-url=", "description=", "config=", "help"])

	except:

		usage()



	for option, value in optlist:

		if option=="-c" or option=="--config":

			settings["config"]=value



	try:

		configreader.load(open(settings["config"], "r"), settings)

	except IOError, e:

		pass



	for option, value in optlist:

		if option=="-h" or option=="--help":

			usage()

		elif option=="-s" or option=="--service":

			settings["service"]=value

		elif option=="-d" or option=="--description":

			settings["description"]=value



	if settings["service"]!="urltea" and len(settings["description"])>0:

		usage()



	try:

		settings["posting url"]=settings[settings["service"]+" url"]

	except:

		usage()



	for option, value in optlist:

		if option=="-u" or option=="--custom-url":

			settings["posting url"]=value



	if len(args)<1:

		usage()



	for u in args:

		print tiny(u, settings)



if __name__=="__main__":

	try:

		main()

	except KeyboardInterrupt, e:

		pass

simple IRC bot written in Ruby

413x () — Tue, 28 Mar 2006 16:10:26 GMT

A simple IRC bot written in Ruby. It's only 100 lines long!



#!/usr/local/bin/ruby



require "socket"



# Don't allow use of "tainted" data by potentially dangerous operations

$SAFE=1



# The irc class, which talks to the server and holds the main event loop

class IRC

    def initialize(server, port, nick, channel)

        @server = server

        @port = port

        @nick = nick

        @channel = channel

    end

    def send(s)

        # Send a message to the irc server and print it to the screen

        puts "--> #{s}"

        @irc.send "#{s}\n", 0 

    end

    def connect()

        # Connect to the IRC server

        @irc = TCPSocket.open(@server, @port)

        send "USER blah blah blah :blah blah"

        send "NICK #{@nick}"

        send "JOIN #{@channel}"

    end

    def evaluate(s)

        # Make sure we have a valid expression (for security reasons), and

        # evaluate it if we do, otherwise return an error message

        if s =~ /^[-+*\/\d\s\eE.()]*$/ then

            begin

                s.untaint

                return eval(s).to_s

            rescue Exception => detail

                puts detail.message()

            end

        end

        return "Error"

    end

    def handle_server_input(s)

        # This isn't at all efficient, but it shows what we can do with Ruby

        # (Dave Thomas calls this construct "a multiway if on steroids")

        case s.strip

            when /^PING :(.+)$/i

                puts "[ Server ping ]"

                send "PONG :#{$1}"

            when /^:(.+?)!(.+?)@(.+?)\sPRIVMSG\s.+\s:[\001]PING (.+)[\001]$/i

                puts "[ CTCP PING from #{$1}!#{$2}@#{$3} ]"

                send "NOTICE #{$1} :\001PING #{$4}\001"

            when /^:(.+?)!(.+?)@(.+?)\sPRIVMSG\s.+\s:[\001]VERSION[\001]$/i

                puts "[ CTCP VERSION from #{$1}!#{$2}@#{$3} ]"

                send "NOTICE #{$1} :\001VERSION Ruby-irc v0.042\001"

            when /^:(.+?)!(.+?)@(.+?)\sPRIVMSG\s(.+)\s:EVAL (.+)$/i

                puts "[ EVAL #{$5} from #{$1}!#{$2}@#{$3} ]"

                send "PRIVMSG #{(($4==@nick)?$1:$4)} :#{evaluate($5)}"

            else

                puts s

        end

    end

    def main_loop()

        # Just keep on truckin' until we disconnect

        while true

            ready = select([@irc, $stdin], nil, nil, nil)

            next if !ready

            for s in ready[0]

                if s == $stdin then

                    return if $stdin.eof

                    s = $stdin.gets

                    send s

                elsif s == @irc then

                    return if @irc.eof

                    s = @irc.gets

                    handle_server_input(s)

                end

            end

        end

    end

end



# The main program

# If we get an exception, then print it out and keep going (we do NOT want

# to disconnect unexpectedly!)

irc = IRC.new('efnet.skynet.be', 6667, 'Alt-255', '#cout')

irc.connect()

begin

    irc.main_loop()

rescue Interrupt

rescue Exception => detail

    puts detail.message()

    print detail.backtrace.join("\n")

    retry

end

Source: rubystuff.org

uP2P — micro P2P file sharing application

413x () — Tue, 28 Mar 2006 15:45:07 GMT



#!/bin/sh

# uP2P.sh 0.0.1, 436 characters (excluding comments)

[ $3 ]&&export W=$1 H="$2 $3" K=`mktemp`;Z=/dev/null;e(){ echo "$*";};n(){

nc $* 2>$Z;};x(){ nc -lp ${H#* } -e $1 &>$Z <$Z&};f(){ cat $K|while read h;do

e $W $1 "$2"|n $h;done };case $# in 4)e $W s "$4"|n $H|while read h p f; do

e $W g "$f"|n $h $p>"$f";done;;5)e $H>$K;e $W d $H|n $4 $5>>$K;x $0;;0)x $0

read w c r;[ $W = $w ]&&case $c in s)f l "$r";;g)cat "$r";;a)e $r>>$K;;d)cat $K

f a "$r";;l)ls|grep "$r"|sed "s/^/$H /";;esac;;esac

Source: uP2P, mentioned here

six line peer-to-peer client/server in ruby

413x () — Tue, 28 Mar 2006 15:39:33 GMT

slonik AZ wrote:

> slashdot published an article on someone's

> 15 lines long Peer-2-Peer application

> http://developers.slashdot.org/article.pl?sid=04/12/15/1953227

> Another person followed up with a 9 line equivalent Perl code.

> I wonder what an equivalent Ruby program would look like?

I did this 9.5 hours ago. Compared to the python one it is not

vulnerable to File stealing attacks (a client can request a file

../foobar and ~/foobar from the python server and will get it back

AFAIK) and 6 lines long. It is however vulnerable to the DRb style

.instance_eval exploits. I will fix this shortly, but I might have to

use 7 lines then.



# Server: ruby p2p.rb password server server-uri merge-servers

# Sample: ruby p2p.rb foobar server druby://localhost:1337 druby://foo.bar:1337

# Client: ruby p2p.rb password client server-uri download-pattern

# Sample: ruby p2p.rb foobar client druby://localhost:1337 *.rb

require'drb';F,D,C,P,M,U,*O=File,Class,Dir,*ARGV;def s(p)F.split(p[/[^|].*/])[-1

]end;def c(u);DRbObject.new((),u)end;def x(u)[P,u].hash;end;M=="client"&&c(U).f(

x(U)).each{|n|p,c=x(n),c(n);(c.f(p,O[0],0).map{|f|s f}-D["*"]).each{|f|F.open(f,

"w"){|o|o<t==0&&D[s(a)]||t==1&&F.read(s(a))||p(a))end;def y()(p(U)+p).each{|u|c(u).f(x(u),

p(U))rescue()};self;end;private;def p(x=[]);O.push(*x).uniq!;O;end}.new.y;sleep)

Source: p2p.rb (Florian Gross), mentioned here