Unicode

Pulling your hairs over some i18n bug or you fix it but are not able to explain what. This is little help in getting fair idea about unicode/codecs/encoding/decoding etc.

Quick tips:

a. It does not make sense to have a string without knowing what encoding it uses.
b. Utf-8 is a way of storing string of Unicode code points.
c. Encoding: Transforming a unicode object into a sequence of bytes
d. Decoding: Recreating the unicode object from the sequence of bytes is known as decoding. There are many different methods for how this transformation can be done (these methods are also called encodings).

Now
Must Read 1. http://www.joelonsoftware.com/articles/Unicode.html
Must Read 2. http://stackoverflow.com/questions/447107/whats-the-difference-between-encode-decode-python-2-x
Continue reading 1: http://farmdev.com/talks/unicode/
Continue reading 2: http://diveintopython.org/xml_processing/unicode.html
Continue reading 3:http://stackoverflow.com/questions/440320/unicode-vs-str-decode-for-a-utf8-encoded-byte-string-python-2-x

Tata Indicom USB Modem on Linux

cat /etc/wvdial.conf

[Dialer Defaults]
Init1 = ATZ
Init2 = ATQ0 V1 E1 S0=0 &C1 &D2 +FCLASS=0
Modem Type = USB Modem
Baud = 460800
New PPPD = yes
Modem = /dev/ttyACM0
ISDN = 0
Stupid mode = 1
Phone = #777
Password = internet
Username = internet


Don’t understand above. Um ok but I am too lazy to explain.

LinkedIn backlash

Linkedin is one of the few sites that has certainly impressed me with it’s clever design. I would rate it very highly for professional networking. It has one very popular feature “recommendations”. Well while I am not against recommending or get recommended by, as I have done both in past. But I see people who
think that more and more people they have in their list (no matter how they know well each other professionally) and more recommendations they have received (mostly by requesting others) would make their prospects better. Umm oh, I wonder why are they are madly behind this. I receive a quite
a few requests often. Some morning you check your emails and you see that some colleague in your company 2 years ago sends you a mail with subject “can you endorse me?”. And the email says something
similar.

Dear ,
I’m sending this to ask you for a brief recommendation of my work that I can include in my LinkedIn profile. If you have any questions, let me know.

Thanks in advance for helping me out.

-

Now this above guy could be someone I don’t know that well how well he/she is skilled. But now I can’t deny the request so in a day or two I would look at some other recommendations available for my other LinkedIn friends, copy some matter and send what is requested for. He happily accepts and send me a nice Thank you email. I see people who worked completely unrelated departments and has probably no ability to judge other’s work, go praising out of good relationships. May be what should happen on Orkut testimonials or somewhere similar.

Does these people who have tens and hundreds of people in network and so many recommendations have no work other than hopping the jobs and sending such requests.

Next time I interview a guy with many endorsements , I would probably more cautious hiring him.

My open source projects

  • Syncer: A event daemon based on Pyro.
  • Stockie: A personal portfolio manager for an Investor
Will soon write more about these projects.

Qemu networking setup

          
------------        ----------
|           |      |  Guest  |
| Host  ----+------+-----    |
|      |    | Hub  |     |   |
|      |tap0|      |tap1 |   |
|      |-----+-----+-----|   |
| eth0      |      |         |
|   |       |      |         |
----+-------       ----------
 |
(Internet)

Host
* Add a hub
# vde_switch  -x -d -tap tap0 -tap tap1
* Assign ip to host's nic
# ifconfig tap0 192.168.1.1
* Setup ip forwarding
Modify /etc/sysctl.conf
net.ipv4.ip_forward=1
* Setup masquerading
# iptables -t nat -A POSTROUTING -o eth0 -j MASQUERADE
* Fire qemu
# vdeqemu -m 1024 -localtime /vm//jos_8.04_01/jos_8.04_01.img

Guest
# ifconfig eth0 192.168.1.2
# route add default gw 192.168.1.1
# vi /etc/resolv.com
# ping google.com

Configuring your ubuntu for faster internet access

While there is a lot already written here my quick howto


$ sudo bash
# apt-get install dnsmasq squid
# echo "listen-address=127.0.0.1" >> /etc/dnsmasq.conf
# vi /etc/dhcp3/dhclient.conf # # vi /etc/resolv.conf  # Add nameserver 127.0.0.1 
# /etc/init.d/dnsmasq restart
# vi /etc/squid/squid.conf 

http_port 3128
visible_hostname localhost

acl all src 0.0.0.0/0.0.0.0

cache_effective_user proxy
cache_effective_group proxy

http_access allow all
icp_access allow all

positive_dns_ttl 1 month
negative_dns_ttl 1 minute
httpd_accel_port 80
httpd_accel_with_proxy on
httpd_accel_uses_host_header on

cache_dir ufs /cache 400 16 256
cache_store_log none         


# mkdir /cache # I have this dir on reizerfs partition
# chown proxy.proxy /cache

# /etc/init.d/squid restart


Configure your browser to use 127.0.0.1:8080.
Also read detailed dnsmasq setup article http://ubuntu.wordpress.com/2006/08/02/local-dns-cache-for-faster-browsing/

Youtube flash videos to DivX (on Linux)

This how I convert flash
I usually use Firefox VideoHelper Addon to download youtube videos. To play them on my Philips DVP5986K DVD player from USB drive, I need to convert it to DivX.

mencoder /home/shon/Desktop/file-864260998.flv -ovc lavc -oac mp3lame -ffourcc DX50 -o out.avi

Using DOT language to produce Flowchart

much better than struggling with the graphical tools.


shon@ubuntu:~$ cat test.dot

digraph FlowChart {

 node [
         fontname = "Bitstream Vera Sans"
         fontsize = 8
         shape = "record"
     ]

 edge [
         fontname = "Bitstream Vera Sans"
         fontsize = 8
         fontcolor = "Red"
     ]

// all blocks
greet [label="Hello, techie", shape="oval"]
which_os [label="What OS do you use?" shape="diamond"]
like_me [label="Great, me too!", shape="oval"]
which_browser [label="You must be using firefox", shape="diamond"]
ff [label="Cool", shape="oval"]
bye [label="Bye", shape="oval"]

// relations
greet -> which_os
which_os -> like_me [label="I use Linux"]
which_os -> which_browser [label="I use Windows"]
which_browser -> ff [label="Right"]
which_browser -> bye [label="what firefox?"]
}

shon@ubuntu:~$ dot test.dot -Tpng -o test.png && eog test.png


Contract verification in Python



import zope.interface.verify

class ITest(zope.interface.Interface):
   def foo(arg1): pass
   def bar(): pass   

class Test(object):
   zope.interface.implements(ITest)
   def foo(self): pass

class Test2(object):
   zope.interface.implements(ITest)
   def foo(self, arg1): pass

class Test3(object):
   zope.interface.implements(ITest)
   def foo(self, arg1): pass
   def bar(self): pass

for cls in (Test, Test2, Test3):
   try:
       if zope.interface.verify.verifyClass(ITest, cls):
           print "OK: %s correctly implements %s" % (cls.__name__, ITest.__name__)
   except Exception, err:
       print "Error detected with %s's implementation: %s" % (cls.__name__, err)

Getting older, getting better and better!

Python programming is joy. I was stuck on python 2.3 at my work for long and could not really get chance to explore later versions. Now that I got the opportunity doing re-architecture of the product I started exploring these. I am more than excited looking at deque, groupby, defaultdict and much more … Also on top of it there exist excellent python softwares like twisted, sqlalchemy, turbogears makes it even more cool.
It’s little pity that the language is stll somewhat less recognized than others. Or there are more hyped languages exist.

Anyways Python rocks!