Horn Clause

#Perl recursive file listing in dir with a pattern in name

2011-10-07T14:57:00.000-07:00

Modified:

use File::Find;

   #Recursive file find with a pattern in name
   find( sub{
              /.*NODE.*\.CAT.*/si && -f $_ and push @bkpfiles, $File::Find::name;
              #-d $_ and push @dirs, $File::Find::name;
            }, $dir );

due to: sh1tn

nohup and hist need some care before use

2011-08-12T15:21:00.000-07:00

I mean you can not do something like:

nohup r prep; something&

nohup: cannot run command `hist': No such file or directory

Well we could run this provided we eval r something.

rsh2/rsh Permission Denied

2011-05-20T06:49:00.000-07:00

Even when everything is set right there could be "Permission Denied" error. .rhosts has all the entries etc.
Then check the permission on .rhosts file:

chmod 644 on users .rhosts file

~rAGU

Search and replace by parsing nested clause across multilines using recursive regex

2011-03-11T08:16:00.000-08:00

Let me start with the answer. The answer is:

perl -p -i -e 'undef $/;$re = qr/\((?:[^()]*|(??{$re}))*\)/;s/(create\s+table

\s+.[a-z,A-Z,0-9,.]*\s*$re)\s*(?!SPARSIFY)/$1 SPARSIFY /gis' test/*

Now the question and story behind it:
Transforming existing code can be bit tricky and less useful sometimes. But at other times it can literally save our jobs! Here is a typical scenario:

FuncName ("Hell brakes $heck if(blah (blah(blah(".
"blah(blah))blah)))", Heaven);

If the above function is called million times at different places and you want to change that crazy looking nested structure inside a function argument what will you do ? Ok, you can slurp the file to a scalar as in here:
http://www.modernperlbooks.com/mt/2009/08/a-one-line-slurp-in-perl-5.html. Then use the recursive regexp idiom:

$re = qr/$(?:[^()]*|(??{$re}))*$/;
$input_scalar =~ s/(Hell\s+brakes\s+.[a-z,A-Z,0-9|.]*\s+if\s*$re)\s*(?!HELLIFY)/$1 HELLIFY /gis;

The $re grabs everything in the nested brackets (note you can not to this with regular regex). The rest is search replace as usual with some Look-Around and grouping. Depends on what you want to do. I wanted to append a string after the nested clause ended.

You already know the short answer! The long answer is below.

Have fun!

sub searchReplaceAcrossLines()
{
    my @files =dir/*; # Read all files in a dir

    my $input_scalar; 

    my @input_array; 

    my $holdTerminator = $/; 

    # Multiline search. Can use instead: undef $*=1;
    undef $/;
#Process each file in the dir
foreach $file (@files) { # Process each file

# Read the file
open(FILE,"$file") or die;
@input_array=
close(FILE);
$input_scalar=join("",@input_array);

#An example
my $re; # A recursive regular expression for everything in brackets
# Do your substitution here.
    $re = qr/$(?:[^()]*|(??{$re}))*$/;
    $input_scalar =~ s/(Hell\s+table\s+.[a-z,A-Z,0-9]*\s*$re)\s*(?!READONLY)/$1 READONLY /gis;

# Write to file
open(OUTPUT,">$file") or die;
print(OUTPUT $input_scalar);
close(OUTPUT);

print $file . "\n";
} #End for

$/ = $holdTerminator; #Restore
print "Search replace complete \n";
return 0; } /end subOne can shorten, optimize etc. But this does what is needed at the moment. dprofpp
Total Elapsed Time = 0.019919 Seconds
User+System Time = 0.019919 Seconds
Exclusive Times
%Time ExclSec CumulS #Calls sec/call Csec/c Name
50.2   0.010 0.010      2   0.0050 0.0050 main::BEGIN
50.2   0.010 0.010      1   0.0100 0.0099 main::searchReplaceAcrossLines
0.00   0.000 0.000      1   0.0000 0.0000 File::Glob::GLOB_BRACE
0.00   0.000 0.000      1   0.0000 0.0000 File::Glob::GLOB_NOMAGIC
0.00   0.000 0.000      1   0.0000 0.0000 File::Glob::GLOB_QUOTE
0.00   0.000 0.000      1   0.0000 0.0000 File::Glob::GLOB_TILDE
0.00   0.000 0.000      1   0.0000 0.0000 File::Glob::GLOB_ALPHASORT
0.00       - -0.000      1        -      - DynaLoader::dl_load_file
0.00       - -0.000      1        -      - DynaLoader::dl_undef_symbols
0.00       - -0.000      1        -      - DynaLoader::dl_find_symbol
0.00       - -0.000      1        -      - DynaLoader::dl_install_xsub
0.00       - -0.000      1        -      - File::Glob::bootstrap
0.00       - -0.000      1        -      - File::Glob::doglob
0.00       - -0.000      1        -      - warnings::import
0.00       - -0.000      1        -      - warnings::BEGIN Here is how profiling works: http://www.perl.com/pub/2004/06/25/profiling.html

Relational XML

2010-08-18T13:51:00.000-07:00

Why use hierarchical data model with relational databases? That is the story of XML in relational databases. Why can't XML be used to define data relations? So I looked around if it existed.

This dude has an idea.

Then came the boss with lotsa more ideii !

Right on!

C# .NET Application deployment

2010-04-03T04:38:00.000-07:00

I am not overly familiar with this stuff. As I try to figure out. Images added to resources should be specified using relative path. If you try Visual Studio is smart enough to suggest.

So the Source filed in the Property tab should like

/YakshaTala;component/Resources/kanlogo.png

YakshaTala is the root folder
Resources is the sub folder

The rest about deployment soon...
It appears this is a common problem. The solution is here
http://geekrick.blogspot.com/2008/08/frustrating-net-framework-sp1-issue.html
and in many other places.Best way is to google the error message deleting application specific part in the error message. I am able to install my app.

What ailes file systems

2009-12-04T13:37:00.000-08:00

File systems have a single region of failure: the table. Corruption of allocation table renders all data waste. Such corruption reduces the problem of finding files in to the known problem of non trivial 'string comparison/search'.

Go write a software to find the file headers in a DVD. We can write one but only if someone can lend a computer that can compute it before I am dead!

So we need an idea that does away single region of failure.

Elements of Abstractions - Computation as simulation of models

2009-09-03T10:11:00.000-07:00

Let us define 'abstraction' as 'hiding' for the purpose of this post. A 'level of abstraction' therefore is amount of hiding details of a particular kind. Elements are in a sense different 'kinds' of 'bricks' that build a level of abstraction.

...more

Questions?

2009-06-15T06:52:00.000-07:00

Questions can be crazy! Look at interviewers on TV. They create so much trouble with simple things and cause put good guys in trouble even if everything they said and did was right they are made to look bad. Why? The trick is in questions they ask.

Questions can be incorrect. What question implies could be out right wrong. More cunning is the warrant of what is implied in a question being wrong. It is hidden so deep that question looks all right. Yet something is odd about it! Wish I could give an example here. I will come up with one.

Therefore, it occurred to me: why do not we have Integrative Calculus? Propositional calculus does not cover questions because questions are not propositions. However there is lot of contribution from questions to everyday logic that propositional calculus can not capture. We therefore need a formal system that can account for questions. I dug to see if there was some research on this topic. Sure, there is. It appears that there is a proposal here.: : in 2001. I am only 9 years behind! A lot of improvement ; It used to be 20 years! But it is not clear how sound the proposal is. There is definitely some scope.

Get a domain name for your url

2008-10-04T17:27:00.000-07:00

www.dot.tk is a cool idea that gets a domain name for URLs.
Try it. It works for me!

www.thoughtslot.tk

iClock

2008-09-23T09:32:00.001-07:00

http://thoughtslot.blogspot.com/2008/09/personica.html

Navigation History Tree

2008-09-16T08:11:00.000-07:00

I always wanted a feature in all kinds of exploratory software utilities: navigation history. Isn't that obvious? Apparently not to firefox or Ie or even the I Suffer !

But someone thought about it; way before I did! A Bob from somewhere thought long ago when I was still learning how to use Multi-ICE, about the need for such a tree. Opera and Konqueror were supposed to have it. I have not seen them!

Got some time? Write a firefox plugin. What say? So I begin here! My ಹೆಜ್ಜೆ ೦.೯ ಆಟ plugin (hejjeh 0.9 alpha)! Will tell ya when it is ready.

Why $?

2008-09-15T19:11:00.001-07:00

The variables in Perl and bash scripts need a $ behind their ass. Why do we need $ in a free stuff like Perl? Let me know if you have an intelligent answer or atleast a solution :)

How developpers think

2008-08-19T12:54:00.000-07:00

INDOS

2008-08-10T21:59:00.000-07:00

Instant Distributed Operating System.
------------------------------------------
Why should computers take a minute to boot (start) while a much cheaper Dvd player can sing instantly? A TV, tape recorder, you name it, they start working the moment they are powered on. One pays lot of money and yet computers tale anywhere between a minute to ten depending on your fate and its own speed.

An engineer will quickly tell you that, "BIOS.. POST...", hold it. I do not care. All we want is a thing we can use to, "do stuff". That explains the need for "Instant".

I have two laptops and a mobile phone. They are always out of sync. Let us forget ubiquitous computing for a while. We need to deel with these multiple devices to make them data location and interface invariant. I'll leave it at that. Fill in the blanks please.

Drivers are not OSs' business. We need a slim OS that just does what its name says, 'operate the system'!

Indos by the way is the Greek name for the river Indus (Sindhu).

How To Manage Contacts in Outlook

2008-08-03T07:30:00.001-07:00

Sun's ceo calls it Lookout! But many use it including me. Managing contacts in Outlook is tricky. Here are few things I do when I move.

By default all email ids are recorded in a file called Outlook.NK2 which is, by generocity of Microsoft, hidden. These are used to auto fill when we type an emil id. These are not stored in the address book. Its default location is:
C:\Documents and Settings\\Application Data\Microsoft\Outlook\Outlook.NK2

is your user login id on the computer.

Application Data is a folder that is hidden from view. Go to Tools->View and select Show Hidden files.

When I move, I copy/backup this file. When I setup outlook on new machine, I zimbly copy the backup file to the default location in the new machine. Address book is a sacred thing. Mine is mostly empty! To manage autofill email address we can use a freeware availale online. It is called NK2View (Download).

Dizzy Logic

2008-06-08T21:48:00.000-07:00

I thought of a word, "Dizzy Logic". I searched to see if it existed already. It does and in an interesting way. Here is an example: Dizzy Logic

Some classic papers in Computer Science

2008-04-09T19:25:00.000-07:00

These have changed our lives more than some, more famous discoveries such as: wave nature of particles, string theory and uncertainty principle.

The list will grow as I learn about them!

[0] Horn's paper: "On sentences which are true of direct unions of algebras"
[1] Codd's paper on Relational Database Model
[2] Shanon's A mathematical theory of communication
[3] C language: developments
[4] Fuzzy Logic - Zadeh
[5] Fuzzy Dizzy sets
[6] Some essays on philosophy of science

What is the Horn's Clause

2008-04-09T18:05:00.000-07:00

It is one of my blogs!

My latest foray into understanding programming from the perspective of Formal Systems resulted in a few blog posts that you can read here, here and here. The interest got a kick when I had to relate a formal debate and its mechanisms to first-order-logic. I was only partially successful. But it has increased my understanding (also misunderstanding).

I noticed that my blog turns into an activists website when I sympathise with certain causes. It is not bad but it also drags me away from what brings me bread: computer science! In an attempt to put all understandings to "ready to understand" form, I will write about my readings in computer science.

Next few things to ecxpect here are:

My definition of the interface construct in Java,

Quicker Sort

Links to older posts related to computer science are bellow.

My first encounter with a computer

Cursors in Java Swing
Perl
Continuation
Spinning Lady
Height of a tree
Information Pollution (this is a bit crazy)