elb-create-lb

elastic load balancing gotcha:

elb-create-lb TheNameMustBeginWithCapitalLetterAndShouldNotIncludeDotsOrUnderscore..

For example, elb-create-lb ExampleCom is ok

elb-create-lb example.com is not.

windows batch file to convert videos to mp3

save this as tomp3.bat

@echo off

setlocal

set filename=%~n1
set filepath=%~df1
set dirname=%~dp1
set dumpfile=%dirname%\audiodump.wav
set outfile=%dirname%\%filename%.mp3
mplayer -ao pcm:fast -af volnorm -vo null -vc null "%filepath%" -dumpfile "%dumpfile%"
lame -h "%dumpfile%" -o "%outfile%"
del "%dumpfile%"
pause
endlocal

and drag and drop the movie to the batch file

clojure tab completion on windows

windows sucks because it does.

so, clji.bat:

@echo off
setlocal
set CLOJURE_HOME=%~dp0\clojure
set CLASS_PATH=%CLOJURE_HOME%\jline-0.9.94.jar;%CLOJURE_HOME%\clojure.jar;%CLOJURE_HOME%\clojure-contrib.jar
java -Djline.words="%CLOJURE_HOME%\all_names.txt" -cp "%CLASS_PATH%" jline.ConsoleRunner clojure.main %*
endlocal

clj.bat:

@echo off
setlocal
set CLOJURE_HOME=%~dp0\clojure
set CLASS_PATH=%CLOJURE_HOME%\jline-0.9.94.jar;%CLOJURE_HOME%\clojure.jar;%CLOJURE_HOME%\clojure-contrib.jar
IF (%1)==() (
    java -Djline.words="%CLOJURE_HOME%\all_names.txt" -cp "%CLASS_PATH%" jline.ConsoleRunner clojure.main
) ELSE (
    java -Djline.words="%CLOJURE_HOME%\all_names.txt" -cp "%CLASS_PATH%" clojure.main %1 -- %*
)
endlocal

clji.bat always starts repl. clj.bat starts repl when no argument is passed. otherwise, it runs the first argument (should be .clj script). it expects there's clojure/ directory at the same level of the batch files. the directory should have some jar files (clojure.jar, clojure-contrib.jar, jline..) and also clojure/ contains allnames.txt that is generated by allnames.clj:

(def all-names (concat (map (fn [p] (keys (ns-publics (find-ns p))))
    '(clojure.core clojure.set clojure.xml clojure.zip))))

(println (apply str
    (interleave (reduce concat all-names)
                (repeat "\n"))))

to run it:

$ clj all_names.clj > all_names.txt

now, modified ConsoleRunner.java (from http://jline.sf.net) that'll actually use all_names.txt:

/*
 * Copyright (c) 2002-2007, Marc Prud'hommeaux. All rights reserved.
 *
 * This software is distributable under the BSD license. See the terms of the
 * BSD license in the documentation provided with this software.
 */
package jline;

import java.io.*;
import java.util.*;

/**
 *  <p>
 *  A pass-through application that sets the system input stream to a
 *  {@link ConsoleReader} and invokes the specified main method.
 *  </p>
 *  @author  <a href="mailto:mwp1@cornell.edu">Marc Prud'hommeaux</a>
 */
public class ConsoleRunner {
    public static final String HISTORY = "jline.history";
    public static final String WORDS = "jline.words";

    public static String[] getWords(String wordsFile) {
        List result = new ArrayList();
        try {
            BufferedReader input = new BufferedReader(
                new FileReader(wordsFile)
            );
            try {
                String line = null;
                while (null != (line = input.readLine())) {
                    result.add(line);
                }
            } finally {
                input.close();
            }
        } catch (FileNotFoundException err) {
            err.printStackTrace();
        } catch (IOException err) {
            err.printStackTrace();
        }
        String[] array = new String[result.size()];
        result.toArray(array);
        return array;
    }

    public static void main(final String[] args) throws Exception {
        String historyFileName = null;

        List argList = new ArrayList(Arrays.asList(args));

        if (argList.size() == 0) {
            usage();

            return;
        }

        historyFileName = System.getProperty(ConsoleRunner.HISTORY, null);

        // invoke the main() method
        String mainClass = (String) argList.remove(0);

        // setup the inpout stream
        ConsoleReader reader = new ConsoleReader();

        if (historyFileName != null) {
            reader.setHistory(new History (new File
                (System.getProperty("user.home"),
                    ".jline-" + mainClass
                        + "." + historyFileName + ".history")));
        } else {
            reader.setHistory(new History(new File
                (System.getProperty("user.home"),
                    ".jline-" + mainClass + ".history")));
        }

        String wordsFileName = System.getProperty(WORDS, null);
        if (null != wordsFileName) {
            //List list = new ArrayList();
            //list.add(new SimpleCompletor(getWords(wordsFileName)));
            //list.add(new FileNameCompletor());
            //list.add(new NullCompletor());
            Completor completor =
                new MultiCompletor(new Completor[] {
                    new SimpleCompletor(getWords(wordsFileName))
                    , new FileNameCompletor()
                });
            reader.addCompletor(
                new ArgumentCompletor(new Completor[] {
                    completor
                    , completor
                }, new SExpr())
            );
        } else {
        }

        String completors = System.getProperty
            (ConsoleRunner.class.getName() + ".completors", "");
        List completorList = new ArrayList();


        for (StringTokenizer tok = new StringTokenizer(completors, ",");
            tok.hasMoreTokens();) {
            completorList.add
                ((Completor) Class.forName(tok.nextToken()).newInstance());
        }

        if (completorList.size() > 0) {
            reader.addCompletor(new ArgumentCompletor(completorList));
        }

        //reader.setCompletionHandler(new CandidateListCompletionHandler());

        ConsoleReaderInputStream.setIn(reader);

        try {
            Class.forName(mainClass).
                getMethod("main", new Class[] { String[].class }).
                invoke(null, new Object[] { argList.toArray(new String[0]) });
        } finally {
            // just in case this main method is called from another program
            ConsoleReaderInputStream.restoreIn();
        }
    }

    private static void usage() {
        System.out.println("Usage: \n   java " + "[-Djline.history='name'] "
            + "[-Djline.words=<path to words file for autocompletion>] "
            + ConsoleRunner.class.getName()
            + " <target class name> [args]"
            + "\n\nThe -Djline.history option will avoid history"
            + "\nmangling when running ConsoleRunner on the same application."
            + "\n\nargs will be passed directly to the target class name.");
    }
}

class SExpr
        extends ArgumentCompletor.AbstractArgumentDelimiter {
    public boolean isDelimiterChar(String buffer, int pos) {
        String c = buffer.substring(pos, pos+1);
        return c.matches("[^\\w-*<>=?]");
    }
}

if -Djline.words=path/to/file/that/has/word/list is passed, it'll use that file to do tab completion. it's quick and dirty. i don't get how jline works. somehow, i had to pass completor (new MultiCompletor(...)) twice to ArgumentCompletor so that tab completion works into middle of line. Also, SExpr is argument delimiter that considers things other than [\w-*<>=?] a delimiter.

so, run mvn package to build jline jar. then put jline jar file under clojure/. then clj.bat and clji.bat would work.

i always spend time to set up development environment then lose interest :P

edl2srt.py

tried make subtitle using mplayer. thankfully, mplayer has -edlfile option. so, using that, I can cue when subtitle should change.

given the following:

subtitle.txt

hello!
how are you?
bye

I can play mplayer -edlfile subtitle.edl movie.avi . and as I play the movie, I press i to cue for new subtitle text from subtitle.txt. Then,

python edl2srt.py subtitle.edl -t subtitle.txt > movie.srt
mplayer movie.avi -sub movie.srt

will play movie.avi with subtitle.

You can get comma separated cue seconds (seconds when i was pressed):

python edl2srt.py subtitle.edl

EDL to srt script is here: It needs optfunc module.

#!/usr/bin/python

# LICENSE: public domain.

"""converts edl file to srt.
EDL (Edit Decision List) file: http://www.mplayerhq.hu/DOCS/HTML/en/edl.html
SRT file: http://forum.doom9.org/archive/index.php/t-73953.html

requires optfunc found at: http://github.com/simonw/optfunc/tree/master"""

def split_float(f):
    i = int(f)
    return i, f - i
def split_float_str(fstr):
    l = fstr.split('.')
    return l[0], l[1]

def sec_to_hour_min_sec(seconds):
    m,sec = divmod(seconds, 60)
    hour,min = divmod(m, 60)
    return (hour,min,sec)

def timestamp(seconds):
    f = float(seconds)
    i,frac = split_float(f)
    hour,min,sec = sec_to_hour_min_sec(i)
    return (hour, min, sec, int(frac*100))

def to_timestamp(seconds, format="%(hour)s:%(min)s:%(sec)s,%(millisec)s"):
    hour,min,sec,millisec = timestamp(seconds)
    return format % {"hour":hour, "min":min, "sec":sec, "millisec":millisec}

class ED(object):
    "edit decision"
    def __init__(self, sec_from=0.0, sec_to=0.0, flag=0):
        self.sec_from = float(sec_from)
        self.sec_to = float(sec_to)
        self.flag = int(flag)

    def to_tuple(self):
        return (self.sec_from, self.sec_to, self.flag)

    def to_pair(self):
        return (self.sec_from, self.sec_to)

class EDL(object):
    def __init__(self, filename=None):
        self.edl = self.read_edl(filename) if filename else []

    def read_edl(self, filename):
        f = open(filename, "r")
        l = []
        for line in f:
            x = line.split()
            l.append(ED(x[0], x[1], x[2]))
        return l


    def seconds(self):
        l = []
        for ed in self.edl:
            l.extend([ed.sec_from, ed.sec_to])
        return l

    def second_pairs(self):
        l = []
        for x in self.edl:
            l.append(x.to_pair())
        return l

class Text(object):
    def __init__(self, filename=None):
        self.text = self.read_text(filename) if filename else []

    def __len__(self):
        return len(self.text)

    def __getitem__(self, key):
        return self.text[key]

    def __str__(self):
        return '\n'.join(self.text)

    def read_text(self, filename):
        f = open(filename, "r")
        l = []
        for line in f:
            x = line.strip()
            if x:
                l.append(x)
        f.close()
        return l

class Subtitle(object):
    def __init__(self, index=0, time_from=0, time_to=0, text=""):
        self.index = index
        self.time_from = to_timestamp(time_from)
        self.time_to = to_timestamp(time_to)
        self.text = text

    def __str__(self):
        return """%u
%s --> %s
%s""" % (self.index, self.time_from, self.time_to, self.text)


def insert_end(seconds, limit=3.0, gap=0.001):
    def delta(x,y):
        d = y - x
        return limit if d > limit else d
    return [(x, x + delta(x,y) - gap) for x,y in zip(seconds, seconds[1:])]

def make_srt(edl, text):
    index = 1
    sec_pairs = insert_end(edl.seconds())

    srt = []
    for i,(sec_from,sec_to) in enumerate(sec_pairs):
        t = text[i] if len(text) > i else None
        srt.append(Subtitle(i+1, sec_from, sec_to, t))
    return srt

def edl2srt(edlname, txtname=None):
    """Usage: %prog edlfile [-t textfile]
    edlfile specification is at:
        http://www.mplayerhq.hu/DOCS/HTML/en/edl.html
    textfile should contain subtitles delimited by new line.

Example
    mplayer a.avi -edlfile a.edl
        during movie play, press i to insert a cue to change subtitle
        defined in a.txt
    %prog a.edl -t a.txt > a.srt
    mplayer a.avi -sub a.srt"""
    edl = EDL(edlname)
    if txtname is None:
        print(','.join([str(x) for x in edl.seconds()]))
    else:
        txt = Text(txtname)
        print '\n\n'.join([str(x) for x in make_srt(edl, txt)])

if __name__ == "__main__":
    import optfunc
    optfunc.run(edl2srt)

tried make subtitle using mplayer.
thankfully, mplayer has -edlfile option.
so, using that, I can cue when subtitle should change.

given the following:

subtitle.txt

    hello!
    how are you?
    bye

I can play `mplayer -edlfile subtitle.edl movie.avi` . and as I play the movie,
I press **i** to cue for new subtitle text from subtitle.txt.
Then,

    python edl2srt.py subtitle.edl -t subtitle.txt > movie.srt
    mplayer movie.avi -sub movie.srt

will play movie.avi with subtitle.

You can get comma separated cue seconds (seconds when **i** was pressed):

    python edl2srt.py subtitle.edl

EDL to srt script is here:
It needs optfunc module.

    #!/usr/bin/python

    # LICENSE: public domain.

    """converts edl file to srt.
    EDL (Edit Decision List) file: http://www.mplayerhq.hu/DOCS/HTML/en/edl.html
    SRT file: http://forum.doom9.org/archive/index.php/t-73953.html

    requires optfunc found at: http://github.com/simonw/optfunc/tree/master"""

    def split_float(f):
        i = int(f)
        return i, f - i
    def split_float_str(fstr):
        l = fstr.split('.')
        return l[0], l[1]

    def sec_to_hour_min_sec(seconds):
        m,sec = divmod(seconds, 60)
        hour,min = divmod(m, 60)
        return (hour,min,sec)

    def timestamp(seconds):
        f = float(seconds)
        i,frac = split_float(f)
        hour,min,sec = sec_to_hour_min_sec(i)
        return (hour, min, sec, int(frac*100))

    def to_timestamp(seconds, format="%(hour)s:%(min)s:%(sec)s,%(millisec)s"):
        hour,min,sec,millisec = timestamp(seconds)
        return format % {"hour":hour, "min":min, "sec":sec, "millisec":millisec}

    class ED(object):
        "edit decision"
        def __init__(self, sec_from=0.0, sec_to=0.0, flag=0):
            self.sec_from = float(sec_from)
            self.sec_to = float(sec_to)
            self.flag = int(flag)

        def to_tuple(self):
            return (self.sec_from, self.sec_to, self.flag)

        def to_pair(self):
            return (self.sec_from, self.sec_to)

    class EDL(object):
        def __init__(self, filename=None):
            self.edl = self.read_edl(filename) if filename else []

        def read_edl(self, filename):
            f = open(filename, "r")
            l = []
            for line in f:
                x = line.split()
                l.append(ED(x[0], x[1], x[2]))
            return l


        def seconds(self):
            l = []
            for ed in self.edl:
                l.extend([ed.sec_from, ed.sec_to])
            return l

        def second_pairs(self):
            l = []
            for x in self.edl:
                l.append(x.to_pair())
            return l

    class Text(object):
        def __init__(self, filename=None):
            self.text = self.read_text(filename) if filename else []

        def __len__(self):
            return len(self.text)

        def __getitem__(self, key):
            return self.text[key]

        def __str__(self):
            return '\n'.join(self.text)

        def read_text(self, filename):
            f = open(filename, "r")
            l = []
            for line in f:
                x = line.strip()
                if x:
                    l.append(x)
            f.close()
            return l

    class Subtitle(object):
        def __init__(self, index=0, time_from=0, time_to=0, text=""):
            self.index = index
            self.time_from = to_timestamp(time_from)
            self.time_to = to_timestamp(time_to)
            self.text = text

        def __str__(self):
            return """%u
    %s --> %s
    %s""" % (self.index, self.time_from, self.time_to, self.text)


    def insert_end(seconds, limit=3.0, gap=0.001):
        def delta(x,y):
            d = y - x
            return limit if d > limit else d
        return [(x, x + delta(x,y) - gap) for x,y in zip(seconds, seconds[1:])]

    def make_srt(edl, text):
        index = 1
        sec_pairs = insert_end(edl.seconds())

        srt = []
        for i,(sec_from,sec_to) in enumerate(sec_pairs):
            t = text[i] if len(text) > i else None
            srt.append(Subtitle(i+1, sec_from, sec_to, t))
        return srt

    def edl2srt(edlname, txtname=None):
        """Usage: %prog edlfile [-t textfile]
        edlfile specification is at:
            http://www.mplayerhq.hu/DOCS/HTML/en/edl.html
        textfile should contain subtitles delimited by new line.

    Example
        mplayer a.avi -edlfile a.edl
            during movie play, press i to insert a cue to change subtitle
            defined in a.txt
        %prog a.edl -t a.txt > a.srt
        mplayer a.avi -sub a.srt"""
        edl = EDL(edlname)
        if txtname is None:
            print(','.join([str(x) for x in edl.seconds()]))
        else:
            txt = Text(txtname)
            print '\n\n'.join([str(x) for x in make_srt(edl, txt)])

    if __name__ == "__main__":
        import optfunc
        optfunc.run(edl2srt)

fundep

FunctionalDependencies example:

> {-# LANGUAGE GeneralizedNewtypeDeriving
>     , FunctionalDependencies
>     , MultiParamTypeClasses #-}

> module Test where

> import Control.Monad.State
> import Control.Monad.Identity

> class (Monad m) => MonadFoo a m | m -> a where
> -- class (Monad m) => MonadFoo a m  where
>     -- save :: m [a]
>     save :: m ()

save has type (MonadFoo a m) => m () . And, although Foo (see below) is an instance of MonadFoo Char, GHC complains that there is No instance for (MonadFoo a Foo) arising from a use of 'save', if functional dependencies isn't used (see commented out code above).

One way to get around is to make save :: m [a] and explicitly annotate each usage of save with :: Foo String (see commented out code of action).

But, using functional dependencies, one can say that m uniquely identifies a. So, GHC will instantiate a with Char on Foo's save, since Foo is an instance of MonadFoo Char.

>     restore :: m [a]
>     push :: a -> m ()

> newtype FooT m a = FooT {
>     runFooT :: (StateT (String, Int) m) a
>     } deriving (Monad, Functor, MonadState (String, Int))

> instance (Monad m) => MonadFoo Char (FooT m) where
>     save = do
>         (current, _) <- get
>         put (current, 0)
>         -- return current
>     restore = do
>         (current, n) <- get
>         put (drop n current, 0)
>         return $ take n current
>     push x = do
>         (current, n) <- get
>         put (x : current, n + 1)

> newtype Foo a = Foo {
>     runFoo :: FooT Identity a
>     } deriving (Monad, Functor
>         , MonadState (String, Int), MonadFoo Char)

> action :: Foo String
> action = do
>     push 'a'
>     save
>     -- save :: Foo String
>     push 'b'
>     push 'c'
>     restore
> test = runIdentity $ runStateT (runFooT (runFoo action)) ("", 0)

FunctionalDependencies example:

> {-# LANGUAGE GeneralizedNewtypeDeriving
>     , FunctionalDependencies
>     , MultiParamTypeClasses #-}

> module Test where

> import Control.Monad.State
> import Control.Monad.Identity

> class (Monad m) => MonadFoo a m | m -> a where
> -- class (Monad m) => MonadFoo a m  where
>     -- save :: m [a]
>     save :: m ()

save has type (MonadFoo a m) => m () .
And, although Foo (see below) is an instance of MonadFoo Char,
GHC complains that there is No instance for (MonadFoo a Foo)
arising from a use of 'save', if functional dependencies isn't used
(see commented out code above).

One way to get around is to make save :: m [a] and explicitly annotate
each usage of save with :: Foo String (see commented out code of action).

But, using functional dependencies, one can say that m uniquely identifies a.
So, GHC will instantiate a with Char on Foo's save,
since Foo is an instance of MonadFoo Char.

>     restore :: m [a]
>     push :: a -> m ()

> newtype FooT m a = FooT {
>     runFooT :: (StateT (String, Int) m) a
>     } deriving (Monad, Functor, MonadState (String, Int))

> instance (Monad m) => MonadFoo Char (FooT m) where
>     save = do
>         (current, _) <- get
>         put (current, 0)
>         -- return current
>     restore = do
>         (current, n) <- get
>         put (drop n current, 0)
>         return $ take n current
>     push x = do
>         (current, n) <- get
>         put (x : current, n + 1)

> newtype Foo a = Foo {
>     runFoo :: FooT Identity a
>     } deriving (Monad, Functor
>         , MonadState (String, Int), MonadFoo Char)

> action :: Foo String
> action = do
>     push 'a'
>     save
>     -- save :: Foo String
>     push 'b'
>     push 'c'
>     restore
> test = runIdentity $ runStateT (runFooT (runFoo action)) ("", 0)

/*

: doub dup + ;
: quad doub doub ;

: swap ( a b -- b a ) ;
: dup ( a -- a a ) ;
: pop ( a -- ) ;
: + ( int int -- int ) ;

int doub(int a)
{
    return a + a;
}

int quad(int a)
{
    return doub(doub(a));
}

*/


#include <iostream>
#include <vector>
#include <string>

struct Object
{
};

typedef Object* ObjectPtr;

struct Int : public Object
{
    int val;
};

typedef Int* IntPtr;

#define DEREF_Int(x) (*static_cast<IntPtr>(x))

std::ostream& operator<<(std::ostream& os, Int const& i)
{
    os<<i.val;
    return os;
}


struct String : public Object
{
    std::string val;
};

typedef String* StringPtr;

#define DEREF_String(x) (*static_cast<StringPtr>(x))

std::ostream& operator<<(std::ostream& os, String const& i)
{
    os<<i.val;
    return os;
}

int main()
{
    std::vector<ObjectPtr> vec;
    Int i;
    i.val = 42;
    vec.push_back(&i);
    String s;
    s.val = "hello world!";
    vec.push_back(&s);
    std::cout<<DEREF_Int(vec[0])<<std::endl
        <<DEREF_String(vec[1])<<std::endl;
    return 0;
}

no!!!!!!!!!!!!!!!!!! I could not install firefox addons for sometime now. I was able to on my Windows machine.. But not on Linux.. Then I found this: http://ubuntuforums.org/showpost.php?p=3965149&postcount=21 So, I disabled ipv6 on firefox and now I can install addons. However, Windows' Firefox can install addons with ipv6 enabled.. Weird..............

ATS WHEEEEEEEEEEE

ATS looks cool.

So... to link things that use math functions, you use -lm.

To compile http://www.ats-lang.org/TUTORIAL/contents/basics.dats, you should do the same because it uses sqrt math function.

atscc basics.dats -lm

And I am writing ats.vim

" Vim syntax file
" Language:   ats

if version < 600
  syntax clear
elseif exists("b:current_syntax")
  finish
endif

:runtime! syntax/c.vim
:unlet b:current_syntax

syn case match

" Keywords
syn keyword atsKeyword implement begin end staload
syn keyword atsKeyword prefix postfix infix infixl infixr op nonfix
syn keyword atsKeyword val and fun fn lam fix rec
syn keyword atsKeyword if then else let in where
syn keyword atsKeyword symintr overload with
syn keyword atsKeyword typedef datatype sortdef
syn keyword atsKeyword case of

syn keyword atsSorts bool char int prop type view viewtype

syn keyword atsTypes string float double

" Comments
syn match atsLineComment /\/\/.*$/
syn region atsFileComment start=/\/\/\/\// end=/\%$/
syn region atsMLComment start=/(\*/ end=/\*)/ contains=atsMLComment
syn region atsCComment start=/\/\*/ end=/\*\//

" Literals
syn keyword atsBoolean true false


if version >= 508 || !exists("did_c_syn_inits")
  if version < 508
    let did_c_syn_inits = 1
    command -nargs=+ HiLink hi link <args>
  else
    command -nargs=+ HiLink hi def link <args>
  endif
  HiLink atsLineComment Comment
  HiLink atsFileComment Comment
  HiLink atsMLComment Comment
  HiLink atsCComment Comment
  HiLink atsKeyword Keyword
  HiLink atsSorts Type
  HiLink atsTypes Type
  delcommand HiLink
endif

let b:current_syntax = "ats"

Things to look at:

• http://github.com/doublec/cf/tree/master
• above is from this
• http://www.call-with-current-continuation.org/fp/

Speaking of concatenative language, I was trying to do something like this: http://www.bluishcoder.co.nz/xyjs/xylistener.html, which is from this post. Lol I just copied it over and tried to do something... http://wekeywiki.googlepages.com/ascl-listener.html. But I gave up on it.. Anyways, it's another TODO thing :(

v8 not build on x86_64

Stupid Google, why would your v8 not build on 64bit system?

scons mode=release library=shared prefix=/usr wordsize=64 || return 1

g++ -o obj/release/third_party/jscre/pcre_compile.os -c -march=x86-64 -mtune=generic -O2 -pipe -ansi -w -O3 -fomit-frame-pointer -m32 -fno-rtti -fno-exceptions -ansi -w -O3 -fomit-frame-pointer -m32 -fPIC -DENABLE_LOGGING_AND_PROFILING -DSUPPORT_UTF8 -DNO_RECURSE -DSUPPORT_UCP

Look at that dreadful -m32 ...

back to archlinux

stupid windows it doesnt' let me fucking build llvm and hssdl doesn't work well on fucking windows fuck fuck fuck.
so, pacman -Syu then
pacman -Sf zsh #for http://www.archlinux.org/news/421/
rm /usr/lib/klibc/include/asm #for http://www.archlinux.org/news/411/
Then,

Section "ServerFlags"
 Option  "AllowEmptyInput" "false"
EndSection

for http://www.archlinux.org/news/424/