Tech Talkies

Good Articles on Internals of C++ and Unix

2011-07-28T06:52:00.000-07:00

"C a glorified assembler" or "C a generalized assembler"

Actually I only really started understanding C when I understood 2 things about it.
1) Anything you code in C finally translates to assembly language.
2) How your compiler interacts with the O.S. loading/linking mechanism.

A) C as a glorified assembler:
You can easily test this.
Use the 'gcc --save-temps ' feature of your gcc compiler to see the assembly language output.

C program to assembly code translation
>>>>>>>>
C program
>>>>>>>>extern int printf(const char *, ...)
int main()
{
printf( "Hello, World!\n");
return 0;
}
#Retain temporary intermediate files generated during preproc, compiling, assembling etc.
gcc --save-temps test.c

>>>>>>>>
Pseudo-Assembly (see link for more accurate example)
>>>>>>>>
.data                              # data section starts at say 0x100
msg ds "Hello, World!\n"           # define string with label as msg and content as "Hello, World!\n"

.text
push sp                            # save the current stack pointer
push msg                           # push the function parameter onto stack
call _printf                       # make the library call
ret   0                            # essentially return 0 as errorvalue to bash/cmd.exe

>>>>>>>>
Since the C language is portable from one platform to another it kind-of acts like a virtual machine (without byte-code generation of-course).
The same C program will compile on different machine-compiler pairs to the specific assembly language and O.S. of the platform in question.

This makes for chip/hardware specific assembly(Intel x86 or Motorola or ARM ...) portability.

Refer:
C to Assembly Translation Article from EventHelix

B) Interaction with O.S. loader/linker/virtual-memory:
The specific C compiler would also link the O.S. specific C runtime properly.

So gcc which is a portable compiler would link in.
a) mingw C runtime on Win32
b) linux C runtime on Linux.

The same C program would also convert to correct assembly/runtime on
Watcom C++, Visual C++ compiler, AIX, HP/UX compilers etc.

Note:
a) printf() comes from the C Standard Library
b) C runtime library contains the startup code which executes before and after main

Refer:
1) C++ runtime environments on HP-UX
2) Internals of C/C++ compiler implementations
3) How to use debug C runtime to debug your application
4) How to write a minimal Kernel in C (a very simple Hello world program which also describes the libc C runtime library)
5) Understanding System Calls
Note:
The C standard library calls like open(), close(), putc(), getc() etc actually just forward the call to O.S. system calls in the linux kernel. The C runtime actually maps a stdlibrarycall to an interrupt vector i.e. system call index number in a lookup table. Then it uses a software interrupt to call the system call (transfers from user mode to kernel mode and back)

----

These are a set of articles that take a look at what happens inside C, C++, Unix internals as we compile and run our programs. The info here is invaluable to debug compile errors, runtime errors and memory issues. You can go through these in your spare time. Take a print out to read in your spare time and go through these articles.

0.What Happens When You Compile and Link a Program
1.What a Compiler Turns Your C Code Into
2. Virtual Base Classes Implementation
3. How the C++ compiler mangles/decorates function names
4. Unix And C-C++ Runtime Memory Management For Programmers

Remotely editing files with ssh, sshmenu, bcvi and vim

2011-07-13T06:39:00.000-07:00

No need to install your favourite vim settings etc on the remote server just use bcvi to start gvim on your workstation.
It uses scp internally to create an editing session from workstation to server
Transparent multi-hop ssh
sshmenu setup howto
Remotely editing files with bcvi and vim
Editing remote files in vim via scp

Browsing XSLT with Vim by adding a Custom Language to Ctags

2011-07-13T06:00:00.000-07:00

XSLT Source Code Browsing with Vim and Ctags

Creating a tags file

1) Test out the regular-expressions for your custom language:

$> egrep 'pattern' *.xsl

2) Copy-paste custom language with the above regular-expressions into ~/.ctags.

$> vi ~/.ctags
--langdef=EXSLT
--langmap=EXSLT:.xsl
--regex-EXSLT=/--regex-EXSLT=/--regex-EXSLT=/$> cd srcdir
$> ctags -R *
$> vi ./tags        #check for tag-entries containing the search patterns
$> vi test.xsl     #Use Ctrl-] to jump from a pattern usage to its definition, Ctrl-T to jump back

Note:
1) Above solution for templates only uses xpath of match="xyz".
The search-key for the template (displays taglist for templates with same xpath).
Potentially a template is uniquely identifiable using match AND mode:

Apprenticeship Patterns: Patterns and Anti-Patterns of Problem-Solving

2011-07-11T07:16:00.000-07:00

The Intellectual Side of Problem-Solving:
(Borrowing heavily from AI terminology)
Imagine a 3D Cube containing the start-state, the goal-state, the problem-space and the solution-paths.
You're essentially scanning a problem space for a solution i.e. a combination of sub-steps which finally lead to goal.
1) Explore the problem space first i.e. try out things
2) Identify what worked or is promising and extend the branches into the sub-problem spaces
3) Recurse over the sub-branches until you've covered enough of the problem-space.
4) If the volume of the problem-space is vast it may help to BackTrack from Goal towards the problem state.

This reduces the volume of problem-space to be probed for possible solution-paths. This is known an "Alph-Beta" Pruning of the (Decision??) Tree.
//TODO: Add Diagram of 3D Problem Space and Decision(??) Tree.

In Nature, Lightning follows a very similar method of Back-Tracking.
It seeks out the easiest path between cloud and ground through an insulating volume of air.
Actually there is an initial weak backtracking path from ground to cloud, followed later by a strong return path.
//TODO: Add picture of Lightning fingers

The Emotional Side of Problem-Solving:
Basicially we must first ask "Why" is problem-solving so important?
Not all problems we face are life-threatening to require immediate attention.
So then what is it that makes solving them so important in the first place.

Refer:
1) Psychology of Computer Programming by Gerald Weinberg
2) Emotional Intelligence

Experience - coming to terms with "immediate failures" vs. "future pay-offs"
1) Try out many things to get a better solution or a solution which appeals to your way of doing things.
2) All the things you try won't/can't succeed at least immediately.
   Mostly many of these "dead-end branches" are just waiting for the right time to flower. You're actually building up a fund of ideas and efforts which will help you overcome some other obstacle.
   Example:
   Unix was a result of dissatisfaction with implementing Multics which itself was a replacement for some other O.S.
   Ken Thompson went on to implement ideas for distributed O.S in CODA, Plan9 etc. 30-40 years later these lessons learned and 'the-roads-tried-but-not-taken' have resulted in writing a 'go' language.
   It's used in Google which puts those same ideas refined over time into concrete working programs.

3) Watching my son getting frustrated when his cycle got stuck in a corner.
   He'd start screaming and banging the cycle into the wall.
   Beating it with red-face and small fists.
   The tears of frustration and incomprehension as to why the universe conspired against his cycling.

4) This felt so much like my own frustration with my own efforts.
   The perceived low return-on-investment of the "meagre" results.
   So many ideas half-implemented, unimplemented and ALL the wonderful things not even attempted i.e. 'the-road-not-taken'.
   The universe almost conspiring to thwart each hope and attempt at magically succeeding at all things.

5) Frustrations comes from other people's expectations.
   And more so our own awareness of not "measuring-up" to their and our own expectations.
   Perfectionism adds heavily to an already sticky situation.
   A feeling that time is running out.
   The impending joining of ranks with washed-out oldies.
   A feeling of helplessness and hopelessness that things can't/won't change no matter what.
   Unable to leave coding and unwilling to change to management (manipulating people not machines).
   Fear of becoming obsolete, of not living up-to the dreams, hopes and self-expectation built up over the years.

----

Patterns: The Middle Path between the Emotional and Intellectual Sides of Problem-Solving
"Why patterns work?!!" AKA "All I needed to know about Patterns I learned in Kindergarten"

Patterns force you to Think and NOT concentrate so much on the Feeling part (which is the cause of frustration)
a) Read, understand, see how the Pattern fits the Problem.
b) Re-evaluate the problem itself.
c) Try carrying out/coding the Pattern.
d) Customizing the Pattern to the situation.
e) Utilize your Feeling side by reflecting on aesthetics as pattern application is a very qualitative activity.

Patterns are primarily a set of ready-made formulas (cookbook-style) for successful problem-solving.

Raise Flagging Hopes:
These are also sufficiently magic-endowed by hearing good things from others etc. This helps you get over the inertia of hopelessness or feeling stuck at a problem. "Who knows this just might work - I've nothing to lose."

Abstract the problem solving process.
De-personalise the problem takes the bite out of it.
If the trial fails it's just the Pattern failing NOT you.
You're fore-warned to try out different patterns for different circumstances.
So you just try some other Pattern or just do something else.
Since the Pattern comes from outside, you give yourself time to understand it.
This is the crucial part where you become accepting of time and effort to customize the Pattern to your particular situation.

Conclusion:
Patterns are very effective Devices for Distraction from Result and Focus onto Process instead.

How-to Repair an Oracle Database using Putty, SQL Developer GUI and some trial-and-error

2011-07-01T00:41:00.000-07:00

I had a problem earlier when I made some changes to the test/dev DB and didn't know how to revert back to correct state.

Issue:
I couldn't delete a row in a table containing incorrect data as the row's primary key was acting as a foreign key in some other table. If I deleted this row it would violate the integrity of the other table(s).

Process:
So I took a backup of the entire DB (just in case I needed it and I did need it!!).
Dropped the constraints, deleted all the related rows (or something like that)
Recreated the constraints and the DB was restored to correct state.
In the process I learned quite a bit about DB's.

Tried out individual commands in the GUI.
Then copied multiple commands into a script.
Ran the scripts, corrected any errors till I got a working script.
Liberally used transaction and rollback to help in the trial-and-error process.

----
I don't remember the specific details but basically
I used a GUI DB browser (SQL Developer) to connect to a Remote DB by port forwarding from my Unix machine.

Working with command-line client is ok if you're really good at it and know all the command syntax etc.
But using a GUI browser really speeds things up as it can manage things like transactions, rollback etc all at the click of a button.

Database GUI SQL Developer allows you to
+ Try out individual commands (with rollback) to see if you're getting the right results.
+ Copy paste small commands into a bigger sql script (with start transaction at start and commit or rollback at script end)
+ Browse a remote DB in GUI mode using a DB connection (using ssh tunnel),
+ backup the entire database (for safety)
+ maybe try out things on a local database first, before attempting the same on the actual DB.

You can export the original DB. Import into a local DB. Try out the operations to check it works.
It may also help to create try out your modifications on a duplicate DB on remote machine instead of touching the problematic DB directly.

1) SQL Developer Setup and Tunneling (port forwarding) instructions are available here.
http://www.cs.tau.ac.il/~boim/courses/databases2009/slides/moreinfo/connection-guide.htm#_Toc150420090
http://www.madirish.net/?article=152
2) You may need to tweak a few things on your Unix machine to get the tunnel working though.
3) Finding somebody in your/other teams who's good at Databases will be a big help.
Local person who can see what the problem is and give quick suggestion is always better.
4) Searching on error messages would help find howto's for fixing the problem.
5) Search error messages in forums like stackoverflow.com will help to quickly find the info or relevant links.

HTH.
----
Oracle SQL Developer

PDF - Oracle SQL Developer User Guide
Oracle SQL Developer at wikipedia
Oracle SQL Developer Tutorial
Connecting Oracle SQL Developer to MS SQL Server
How-to Export Tables/Entire DB with Oracle SQL Developer

Oracle SQL*Plus command line interface (CLI)

SQL*Plus CLI FAQ
SQL*Plus CLI command reference
SQL*Plus Tutorial

Network and SysAdmin, Scripting, Debugging, O.S. Books

2011-06-23T10:30:00.000-07:00

[System Administration]

UNIX and Linux System Administration Handbook (4th Edition) by Evi Nemeth, Garth Snyder, Trent R. Hein and Ben Whaley (Jul 24, 2010)

Linux Administration Handbook by Trent R. Hein

Essential System Administration, Third Edition by Æleen Frisch (Aug 15, 2002)

Linux System Administration White Papers: A Compilation of Technical Documents for System Administrators by Olaf Kirch, Eric Raymond and Lars W. Wirzenius (Sep 20, 1999)

Linux in a Nutshell by Ellen Siever, Stephen Figgins, Robert Love and Arnold Robbins (Sep 29, 2009)

======================

[Network Administration]

Linux Network Administrator's Guide by Tony Bautts, Terry Dawson and Gregor N. Purdy (Feb 10, 2005)

LINUX Network Administrators Guide: 508 pages by Olaf Kirch and Terry Dawson (Jan 5, 2009)

The Accidental Administrator: Linux Server Step-by-Step Configuration Guide by Don R Crawley (Oct 27, 2010)

Linux TCP/IP Network Administration by Scott Mann (Jul 26, 2001) TCP/IP stack understand, configure and troubleshoot servers

Linux Firewalls (3rd Edition) by Robert L. Ziegler

Linux Networking Cookbook by Carla Schroder

Internet Routing Architectures (2nd Edition) by Sam Halabi

========================

[Network and System Administration]

The Practice of System and Network Administration, Second Edition by Thomas A. Limoncelli, Christina J. Hogan and Strata R. Chalup (Jul 15, 2007)

Red Hat Linux Networking and System Administration by Terry Collings and Kurt Wall (Oct 21, 2005)

=====================

[Troubleshooting]

Linux Troubleshooting Bible by Christopher Negus and Thomas Weeks (Jul 30, 2004)

Linux® Debugging and Performance Tuning: Tips and Techniques by Steve Best (Oct 20, 2005)

Debugging Embedded Linux (Digital Short Cut) by Christopher Hallinan (Aug 22, 2007)

Nmap Network Scanning: The Official Nmap Project Guide to Network and Security Scanning by Gordon Fyodor Lyon

Linux Troubleshooting for System Administrators and Power Users 2006

Malware Analyst's Cookbook and DVD: Tools and... by Michael Ligh

Hacking: The Art of Exploitation, 2nd Edition by Jon Erickson

----

Wireshark Network Analysis: The Official Wireshark Certified Network Analyst Guide by Laura Chappell

The Art of Debugging with GDB, DDD, and Eclipse by Norman Matloff

Network Flow Analysis by Michael W. Lucas

Build Your Own Security Lab: A Field Guide for Network Field Testing. by Michael Gregg

=====================

[Performance Tuning]

System Performance Tuning, 2nd Edition (O'Reilly System Administration) by Gian-Paolo D. Musumeci and Mike Loukides (Feb 2002)

Performance Tuning for Linux® Servers by Sandra K. Johnson, Gerrit Huizenga and Badari Pulavarty (Jun 6, 2005)

Optimizing Linux® Performance: A Hands-On Guide to Linux® Performance Tools by Phillip G. Ezolt (Mar 24, 2005)

Red Hat Linux Security and Optimization by Mohammed J. Kabir (Dec 1, 2001)

======================

[RHCE]

Red Hat® Certified Technician & Engineer (RHCT and RHCE) Training Guide and Administrator's Reference by Asghar Ghori (Aug 10, 2009)

===================

[Scripting]

Python for Unix and Linux System Administration by Noah Gift and Jeremy Jones (Aug 29, 2008)

Learning the bash Shell: Unix Shell Programming (In a Nutshell (O'Reilly)) by Bill Rosenblatt

Practical Guide to Linux Commands, Editors, and Shell Programming, A (2nd Edition) by Mark G. Sobell (Nov 29, 2009)

Linux Command Line and Shell Scripting Bible, Second Edition by Richard Blum and Christine Bresnahan (Apr 12, 2011)

Automating Linux and Unix System Administration (Expert's Voice in Linux) by Nathan Campi and Kirk Bauer (Dec 24, 2008)

Linux Command Line and Shell Scripting Bible, Second Edition by Richard Blum

Regular Expressions Cookbook by Jan Goyvaerts

Perl Best Practices by Damian Conway

===================

[Linux Operating System]

Modern Operating Systems (3rd Edition) by Andrew S. Tanenbaum

Professional Linux Kernel Architecture (Wrox... by Wolfgang Mauerer

Understanding the Linux Kernel, Third Edition by Daniel P. Bovet

Understanding Linux Network Internals by Christian Benvenuti

Linux Kernel Development (3rd Edition) by Robert Love

Linux System Programming: Talking Directly to the Kernel and C Library. by Robert Love

Linux Device Drivers, 3rd Edition by Jonathan Corbet

Write Great Code: Volume 1: Understanding the Machine by Randall Hyde

IA-64 Linux Kernel: Design and Implementation by David Mosberger

x86 Instruction Set Architecture by Tom Shanley

Windows® Internals: Including Windows Server... by Mark Russinovich

A Guide to Kernel Exploitation: Attacking the core. by Enrico Perla B.Sc. C

UNIX® Systems for Modern Architectures: Symmetric Multiprocessing and Caching for Kernel Developers. by Curt Schimmel

----

[Parallel and Multi threading]

Synchronization Algorithms and Concurrent Programming. by Gadi Taubenfeld

The Art of Concurrency: A Thread Monkey's Guide to Parallel Applications.. by Clay Breshears

The Practice of Parallel Programming by Sergey A. Babkin

Professional Multicore Programming: Design and Implementation for C++ Developers (Wrox). by Cameron Hughes

======================

[Enterprise]

Event-Driven Architecture: How SOA Enables the Real Time Enterprise. by Hugh Taylor

SOA in Practice: The Art of Distributed System design. by Nicolai M. Josuttis

SOA Design Patterns (The Prentice Hall Service-Oriented Computing Series from Thomas Erl) by Thomas Erl Hardcover

SOA Principles of Service Design by Thomas Erl

Enterprise Integration Patterns: Designing, Building and Deploying Messaging Solutions. by Gregor Hohpe

Restful Web Services by Leonard Richardson

=====================

Valgrind Cheat-Sheet Notes

2011-06-18T05:33:00.000-07:00

Running Notes on Valgrind Memcheck quick-start

Original document @ http://valgrind.org/docs/manual/quick-start.html

=======================================================

1) Compile your program with following options to gcc:

-g //Debug mode

-O0 //No optimization

valgrind --leak-check=yes myprog arg1 arg2

--leak-check=yes //default valgrind tool

Turns on Memcheck profiling

2.6. Core Command-line Options

--tool= [default: memcheck]

Run the Valgrind tool called toolname, e.g. Memcheck, Cachegrind, etc.

-q, --quiet

Run silently, and only print error messages. Useful if you are running regression tests or have some other automated test machinery.

-v, --verbose

Be more verbose. NOTE: Repeating the option increases the verbosity level.

Dump extra information on various aspects of your program, such as:

the shared objects loaded,

the suppressions used,

the progress of the instrumentation and execution engines and

warnings about unusual behaviour.

-----------------------------------------------------------------------------------------------------------------------------------------

--trace-children= [default: no]

This is necessary for multi-process programs.

trace into sub-processes initiated via the fork/exec system calls.

--child-silent-after-fork= [default: no]

Use to silence confusing XML output from child when --trace-children=yes is used.

--track-fds= [default: no]

print out a list of open file descriptors on exit.

Along with each file descriptor is printed a stack backtrace of where the file was opened and file/socket details like name etc.

--log-file=

send all of its messages to the specified "filename.%p.%q{PerProc-EnvVariable}"

where %p=CurrentProcID and %q{UniquePerProcEnvVariable} is used to identify a process by the unique value of its PerProc-EnvVariable.

something like a ProcNumber maybe.

used along with --trace-children=yes for multiprocess applications.

[Error Related options:]

These options are used by all tools that can report errors, e.g. Memcheck, but not Cachegrind.

--xml= [default: no]

important parts of the output (e.g. tool error messages) will be in XML format rather than plain text

the XML output will be sent to a different output channel than the plain text output

i.e. you also must use one of --xml-fd, --xml-file or --xml-socket to specify where the XML is to be sent.

Note: the destination of the plain text output is controlled by --log-fd, --log-file and --log-socket

--xml-file=

Specifies that Valgrind should send its XML output to the specified file. It must be used in conjunction with --xml=yes.

--demangle= [default: yes]

Supression files contain C++ function names in their mangled form so turn off mangling for supressions.

Turn on supressions for human readability.

--num-callers= [default: 12]

Use this if the stack trace is not big enough, to get more call-stack depth

specifies the maximum number of entries shown in stack traces that identify program locations.

errors are commoned up using only the top four function locations (the place in the current function, and that of its three immediate callers).

--error-limit= [default: yes]

When enabled, Valgrind stops reporting errors after 10,000,000 in total, or 1,000 different ones, have been seen.

--track-origins=yes

Helps analyse the root cause of uses of uninitialised values. Otherwise you get generic messages like "Conditional jump or move depends on uninitialised value(s)"

--error-exitcode= [default: 0]

Specifies an alternative exit code to return if Valgrind reported any errors in the run (??as in #define TestSuiteFailed 100 in cppunit testcase??)

... useful for using Valgrind as part of an automated test suite, since it makes it easy to detect test cases

for which Valgrind has reported errors, just by inspecting return codes.

--suppressions= [default: $PREFIX/lib/valgrind/default.supp]

Specifies an extra file from which to read descriptions of errors to suppress. You may use up to 100 extra suppression files.

--gen-suppressions= [default: no]

When set to yes, Valgrind will pause after every error shown and print the line:

---- Print suppression ? --- [Return/N/n/Y/y/C/c] ----

Valgrind will print out a suppression for this error. You can then cut and paste it into a suppression file if you don't want to hear about the error in the future.

This option is particularly useful with C++ programs, as it prints out the suppressions with mangled names, as required.

You may want to common up similar ones, by adding wildcards to function names, and by using frame-level wildcards.

The wildcarding facilities are powerful yet flexible, and with a bit of careful editing, you may be able to

suppress a whole family of related errors with only a few suppressions.

... the -v option which prints out all used suppression records.

--db-attach= [default: no]

When enabled, Valgrind will pause after every error shown and print the line:

---- Attach to debugger ? --- [Return/N/n/Y/y/C/c] ----

--db-command= [default: gdb -nw %f %p]

Specify the debugger to use with the --db-attach command. The default debugger is GDB.

--read-var-info= [default: no]

Memcheck gives more detailed description of illegal address in its output including variable declaration line/file and thread info.

--run-libc-freeres= [default: yes]

Force libc.so to free its private malloc's. These are normally NOT freed but fool valgrind into logging false positives.

Note: forcing call to libc-freeres() at the program exit MAY give problems with older buggy glibc versions.

================================================================================================================

[Setting Default Options]

Note that Valgrind also reads options from three places:

1. The file ~/.valgrindrc

2. The environment variable $VALGRIND_OPTS

3. The file ./.valgrindrc

These are processed in the given order, before the command-line options. Options processed later override those processed earlier; for example, options in ./.valgrindrc will take precedence over those in ~/.valgrindrc.

Please note that the ./.valgrindrc file is ignored if it is marked as world writeable or not owned by the current user. This is because the ./.valgrindrc can contain options that are potentially harmful or can be used by a local attacker to execute code under your user account.

Any tool-specific options put in $VALGRIND_OPTS or the .valgrindrc files should be prefixed with the tool name and a colon. For example, if you want Memcheck to always do leak checking, you can put the following entry in ~/.valgrindrc:

--memcheck:leak-check=yes

This will be ignored if any tool other than Memcheck is run. Without the memcheck: part, this will cause problems if you select other tools that don't understand --leak-check=yes.

================================================================================================================

[Threading Support:]

+ "your program will use the native threading library, but Valgrind serialises execution so that only one (kernel) thread is running at a time.

...

threaded apps run only on one CPU, even if you have a multiprocessor or multicore machine.

...

Valgrind doesn't schedule the threads itself. It merely ensures that only one thread runs at once,

using a simple locking scheme. The actual thread scheduling remains under control of the OS kernel."

+ "if you have some kind of concurrency, critical race, locking, or similar, bugs.

In that case you might consider using the tools Helgrind and/or DRD to track them down."

+ "On Linux, Valgrind also supports direct use of the clone system call, futex and so on. clone is supported

where either everything is shared (a thread) or nothing is shared (fork-like); partial sharing will fail.

Again, any use of atomic instruction sequences in shared memory between processes will not work reliably."

+ "Valgrind has a fairly complete signal implementation. It should be able to cope with any POSIX-compliant use of signals."

Signal Handling:

+ "If your program dies as a result of a fatal core-dumping signal, Valgrind will generate its own core file (vgcore.NNNNN) containing your program's state."

"the core dumps do not include all the floating point register information. In the unlikely event that Valgrind itself crashes,

the operating system will create a core dump in the usual way."

Memory Footprint

"Memory consumption of your program is majorly increased whilst running under Valgrind.

This is due to the large amount of administrative information maintained behind the scenes.

Another cause is that Valgrind dynamically translates the original executable.

Translated, instrumented code is 12-18 times larger than the original so you can easily end up with 50+ MB of translations when running (eg) a web browser."

==================================================================================================================
Valgrind:

memcheck,
cachegrind,
multi-threaded

Valgrind Article on Memory Debugging and Profiling Howto
Valgrind Howto

Open Source Projects and PeopleWare

2011-06-06T03:09:00.000-07:00

Karl Fogel is one of Subversion maintainers.
He shares his experience with Open Source in his online free book "Producing Open Source Software"
Also Check out the video's at the bottom of the page.
Karl Fogel's online book on Producing Open Source Software
Video - How Open Source Projects Survive Poisonous People (And You Can Too)
Video - Principles of Participation for Open-Information Communities by Karl Fogel at Google Talk
Podcast on distributed development by Ben and Fiz

Useful Collection of Linux Server Tutorials to Configure Different Services

2011-01-29T00:01:00.000-08:00

1) Linux Home Server Howto:
A Superb collection of howtos which explain howto configure different services like FTP, SSH, NTP etc.on linux. Gives very useful commands and sample output to show how to get information, change settings, sample config files and relevant amount of background information to make it customizable for your specific needs.
2) Linux Home Networking Quick Tutorials:
Similar super collection of tutorials on different aspects of networking on linux.

Both these sites complement each other well and are more usable when used parallely.

Valgrind website updation on Eclipse IDE integration via LinuxTools plugin suite

2011-01-09T05:17:00.000-08:00

Request to update Valgrind Frontend/GUIs page sent to Valgrind-Developer list.
Contains useful info for anyone interested in GUI based debugging of C/C++ programs using Valgrind etc.
>>>>>>>>>>>>>>>>>>>>>>

Hi,

This is regarding an updation to the "Valgrind Frontends/GUIs" page: 
http://www.valgrind.org/downloads/guis.html

LinuxTools is a GUI plugin suite to  integrate Valgrind into the Eclipse C++ 
CDT.
Could you add an entry for this in "Valgrind Frontends/GUIs" page?

As can be seen on forums like stackoverflow.com lots of people are interested in
using Valgrind (and such other tools) from the Eclipse IDE but don't know
how to go about doing it. Having an entry on Valgrind's pages would help out
such people.

Some useful links on usage of Valgrind with LinuxTools:

[Website]
This is the Eclipse Linux Tools website:
http://www.eclipse.org/linuxtools/index.php

2) Valgrind support page:
http://www.eclipse.org/linuxtools/projectPages/valgrind/

[Usage]
1) Valgrind User Guide (Wiki):
http://wiki.eclipse.org/Linux_Tools_Project/Valgrind/User_Guide

2) How-to configure Valgrind plugin of Eclipse (with Video Demos):
http://www.eclipse.org/linuxtools/projectPages/valgrind/

3) How-to configure Callgrind plugin of Eclipse:
http://www.eclipse.org/linuxtools/projectPages/callgraph/

4) How-to use Valgrind with Eclipse as an External Tool:
http://kapo-cpp.blogspot.com/2007/02/detecting-memory-leak.html

[Download]
Eclipse IDE for C/C++ Linux Developers 
(includes Incubating components like valgrind, gprof, systemtap etc) (120 MB): 
http://techtalkies.blogspot.com/2010/09/howto-install-eclipse-cdt-for-c.html

[Installation]
My blog post "Howto install Eclipse CDT for C++ programming on Linux":
http://techtalkies.blogspot.com/2010/09/howto-install-eclipse-cdt-for-c.html

- Gurudutt Mallapur.

>>>>>>>>>>>>>>>>>>>>>>

P.S.:
Some history on the origin of this post: A mail I sent to the Valgrind Developer list on 2010-10-07.

It seems to be unanswered to date and sits quietly in the archives @http://thread.gmane.org/gmane.comp.debugging.valgrind.devel/12202. I followed all the directions for submitting to the dev-list AFAIK. Though how it ended up in the debugging section I don't recollect. Actually I tried mailing multiple times/ways but all I got was a bounce-back message even after sending the mail from yahoo (disabling html). Tried everything I could think of to get the message across ;-). Finally found the obituary of my post in the archives.

Conclusion: Anyway I'm glad I've got my own blog to capture this knowledge for anyone who needs it.

Qualities of a Great Programmer

2011-01-02T02:16:00.000-08:00

Types of Programmers (Beginner to Great)

Linux FileSystems

2011-01-02T02:00:00.000-08:00

Howto Speed Up Your Work Using Linux Command Line Tools

2010-12-28T04:44:00.000-08:00

Using Multiple User Profiles in FireFox

2010-12-28T04:13:00.000-08:00

Howto Setup FireFox4 beta 8 on Linux Fedora Core 14

2010-12-28T03:43:00.000-08:00

1) Backup your current Firefox 3 profiles
tar -cvzf $HOME/mozilla-firefox-profiles-backup.tar.gz $HOME/.mozilla/firefox/

2) Change to root user for below actions:

3) Add repositories for downloading FireFox4 for FC14:
yum --nogpgcheck install http://rpm.livna.org/livna-release.rpm http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-stable.noarch.rpm http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-stable.noarch.rpm

## Remi Dependency on Fedora 14 ##
# These below repos didn't work out for me got error message saying system-release >=15 required for
# rpm -Uvh http://download1.rpmfusion.org/free/fedora/rpmfusion-free-release-rawhide.noarch.rpm
#rpm -Uvh http://download1.rpmfusion.org/nonfree/fedora/rpmfusion-nonfree-release-rawhide.noarch.rpm

## Fedora 14 ##
rpm -Uvh http://rpms.famillecollet.com/remi-release-14.rpm

Install Firefox4:
yum --enablerepo=remi list firefox4
yum --enablerepo=remi install firefox4

Create different Profile for Firefox4:
firefox --ProfileManager (Create 2 profiles "Default User" and "FF4")

Start Firefox with FF4 profile using command:
firefox4 -P FF4

Or start Firefox 3.6.x with command:
firefox -P 'Default User'

Reference:
http://www.if-not-true-then-false.com/2010/install-firefox-4-on-fedora/
http://www.fedorafaq.org/#installsoftware

Note: Found what I needed was the above steps. Got most of them from these above 2 sources. Either of them singly didn't work out for me so clubbing together the total install steps into this post

Networking Protocol, RFC and Administration Links

2010-12-23T23:48:00.000-08:00

Introduction to Network administration

Email
1) Email Bible: Internet Email Protocols: A Developer's Guide [Paperback] by Kevin Jhonson
2) Top-Down Overview: Wood, D (1999). Programming Internet Mail. O'Reilly
3) Uses VB Source: Rhoton, J (1999). Programmer's Guide to Internet Mail: SMTP, POP, IMAP, and LDAP
4) Totally NT Oriented: Hughes, L (1998). Internet e-mail Protocols, Standards and Implementation. Artech House Publishers

Network Configuration
Linux Network Configuration
Linux Security Administrator's Guide
The Linux Documentation Project Guides
VPN HOWTO
___The TCP-IP Guide - Read Online Free
___The TCP-IP Guide -- Table of Contents

RFC's:
Post Office Protocol - Wikipedia, the free encyclopedia
RFC 1081 - Post Office Protocol Version 3
RFC 2449 - POP3 Extension Mechanism
RFC 2595 - Using TLS with IMAP, POP3 and ACAP
RFC 2616 - Hypertext Transfer Protocol -- HTTP-1.1
RFC 2822 - Internet Message Format
RFC 3164 - The BSD Syslog Protocol
RFC 3207 - SMTP Service Extension for Secure SMTP over Transport Layer Security
RFC 3507 - Internet Content Adaptation Protocol (ICAP)
RFC 5034 - The Post Office Protocol (POP3) Simple Authentication and Security Layer (SASL) Authentication Mechanism
RFC 5321 - Simple Mail Transfer Protocol

Study Notes RARP Protocol

2010-12-18T08:05:00.001-08:00

Study Notes on Reverse Address Resolution Protocol:

(Reference Chapter 6: Internetworking with TCP/IP: Vol 1 Principles, Protocols and Architecture - 3rd Ed. by Douglas E. Comer)

1) RARP is used by diskless machines which can't "remember" their IP address after a boot.

They send a physical-address (ex: ethernet NIC card's unique id) to RARP server(s) which reply back with IP address for that particular physical address.

Note: A machine can query IP address for another machine by supplying that machine's physical address. ?? Used by subnet routers to setup routing tables for its children??

2) RARP uses only ethernet frames as it can't use IP/TCP protocols without an IP address.

On getting hold of the IP address it uses TFTP for loading the boot image from the remote image server.

3) Request Message broadcast by QueryingMachine (to RARP server) as an Ethernet Frame:

PREAMBLE,

SRC-ADDR=QueryingMachine-physical-address,

DEST-ADDR=broadcast-physical-address,

FRAME-TYPE=RARP,

FRAME-DATA=(REQUEST, QueryingMachine-physical-address, target-physical-address), //227 bits (28 Octets) long frame data

CRC

Note:

a) The Ethernet Frame Header may be processed only by NIC card, so the the QueryingMachine-physical-address is repeated in frame data so it's accessible to the O.S.

b) A QueryingMachine can also ask the RARP server to lookup a target-machine's IP address by supplying the target-physical-address.

In such a case the target-physical-address would be different from sender-physical-address. ??Could be used by subnet routers to setup routing tables for its children??

Reference:Fig 2.8 for diagram of Ethernet Frame in Comer)

TODO: Need to cross-check how 2 physical addresses of 48 bits (6 octets) each can fit into the 227bits (28 octet) frame data

4) Reply Message sent by RARP server to QueryingMachine as an Ethernet Frame:

PREAMBLE,

SRC-ADDR=RARPServer-physical-address,

DEST-ADDR=QueryingMachine-physical-address,

FRAME-TYPE=RARP,

FRAME-DATA=(REPLY,QueryingMachine-physical-address, target-physical-address, target-IP-address), // ?? Used to update a subnetting routers routing table ??

CRC

Note:

RARP server sends the target-IP-address to the QueryingMachine and NOT the target machine.

??Could be used by subnet routers to setup routing tables for its children??

5) RARP REQUESTs are retryed by QueryingMachine

a) Looping at periodic intervals to avoid server overload (used for critical remote boot situations)

b) fixed number of retries to avoid network flooding. (used in non-critical remote boot situations)

6) Flooding can occur in case of failed PrimaryServer. This is avoided as follows:

a) REQUEST flooding by QueryingMachine is avoided by Secondary Servers replying back only on the 2nd REQUEST.

b) REPLY flooding is avoided in case of failed Primary Server by Secondary Servers replying back with randomly differing delays of REPLY.

Compare features of different wiki software

2010-12-10T06:53:00.000-08:00

Looking for the right wiki to build up your own hobby/group/professional wiki?

I was just looking for a small nifty wiki to use as a scratchpad to collect technical tid-bits for my work/learning. Didn't want to install/administer stuff but wanted to be able to link up the tid-bits as I found connections between them. Found good candidates Tiddlywiki/Twiki using WikiMatrix's comparison table.

Too many wikis with differing features, limitations and target audiences make it tough to decide. You can easily end up spending a lot of time/effort in installing, administering, learning to use a wiki.

WikiMatrix has a wiki comparison wizard which allows you to select a small set of options to figure out which wiki s/ws are closest to what you're looking for.
Then it creates a comparison table with filterable feature-set to view only the features you're looking for in your dream wiki.

The site also allows you to compare other things like blogs etc.

Network Debug Utilities

2010-12-06T02:49:00.000-08:00

Networking:

tcpdump
ping
traceroute

netstat

Displaying Connections

Netstat - Wikipedia, the free encyclopedia

RFC's:
SMTP
HTTP
FTP

wireshark
wireshark bibliography, articles

SysAdmin:
Linux Newbie Admin Guide
Linux Network Admin Guide
Linux Sys Admin Guide

STUB: TechTalk: C++ : What happens during compilation?

2010-12-01T11:21:00.000-08:00

A) Phases of compilation:
1) compiler,
Process of compilation ,
2) linker, linking, preprocessor, preprocessing, assembler, assembling,

B) Different types of Outputs

1) object-file (.o/.obj),
library(.a/.so (Linux), .lib/.dll - Windows),
static-library (.a, .lib),
dynamic-library(.so, .dll),
name-mangling

G++:

shared-object-file, --save-temps

VC++:
release/debug,
multi/single threaded,
dll,
importlibrary,
.defs file,
export/import symbols

Linux KVM Kernel Virtual Machine

2010-12-01T11:19:00.000-08:00

Linux KVM: Linux Kernel Virtual Machine
apt-get install -y kvm libvirt-bin ubuntu-vm-builder qemu bridge-utils
apt-get install -y ubuntu-virt-server ubuntu-virt-mgmt #KVM server utils and management GUI

Reviews of Classic Technical Books

2010-12-01T11:14:00.000-08:00

[Book Reviews]

Technical:
Apprenticeship Patterns - Guidance for the aspiring software craftsman
Code Reading : The Open Source Perspective
Why Programs Fail by Andreas Zeller

Mash-ups:
Hacking FireFox : More than 150 hacks, mods and customizations

Problem Solving:
How to Solve It by G. Polya
How to Solve It by Computer by Dromey
Lateral Thinking by Edward De Bono

Soft Skills:
How to Win Friends and Influence People by Dale Carnegie

BookReading:
How To Choose Books
Why Read Books

Remote Debugging with GDB

2010-11-07T04:27:00.001-08:00

Remote debugging:
Connecting to remote target
    a) (gdb) target remote /dev/ttyb   # serial-device
    b) (gdb) target remote host:port
    c) (gdb) target remote protocol:host:port
    d) (gdb) target remote | middleman-command   # gdb talks to a middleman command

Transfer files:
    remote put hostfile targetfile
    remote get targetfile hostfile
    remote delete targetfile

    (gdb) load filename    # this command is used instead of 'run' in case of remote debugging
    (gdb) break
    (gdb) step
    (gdb) continue
    (gdb) detach
    (gdb) disconnect

a) Remote gdbserver on target with gdb on host (Need O.S. for this):
     target> gdbserver /dev/com1 emacs foo.txt
    target> gdbserver host:2345 emacs foo.txt
    target> gdbserver --attach /dev/com1 pid

    # Run a wrapper for the debugee program on the target-side
    target> gdbserver --wrapper env LD_PRELOAD=libtest.so -- :2222 ./testprog

    #Connect to the target gdbserver from my host gdb
    $ gdb myprogram
    (gdb) target remote myhost:9999
            0x00007f215893ba60 in ?? () from /lib64/ld-linux-x86-64.so.2
    (gdb) b main
    (gdb) continue

   # Send commands to gdbserver using the monitor command
    monitor help      # List the available monitor commands.
    monitor set debug 0 | 1      # Disable or enable general debugging messages
    monitor set remote-debug 0|1    # Disable or enable debugging messages of the remote protocol
    monitor exit

   See Also: Remote Configuration
   More in-depth internal look at Remote Protocol

b) Remote Stub: Used on Embedded devices without an O.S.

Blogs:
1) http://blog.flameeyes.eu/2010/02/20/remote-debugging-with-gdb-part-2-gdb
2) http://www.gentoo.org/proj/en/qa/backtraces.xml

Debugging Multiple Processes/Threads with GDB

2010-11-07T04:26:00.000-08:00

Debugging multiple inferiors and programs
Gdb allows you to debug multiple programs at once without exiting the process you're currently running.
Gdb uses an inferior as a handle for a process. An inferior is attachable/detachable from a process
info inferiors # display list of current inferiors.

     (gdb) info inferiors
       Num  Description       Executable
       2    process 2307      hello
     * 1    process 3401      goodbye

Switch to another inferior:
inferior infno # make inferior number infno the current inferior

Loading multiple inferiors:

1)    add-inferior [ -copies n ] [ -exec executable ] # n defaults to 1 and optional exec gives an empty inferior
2)    clone-inferior [ -copies n ] [ infno ]    # n defaults to 1 and infno defaults to current inferior number

Ending the inferiority complex:
remove-inferior infno        # Remove the empty inferior Note: Can't remove an inferior with a running assoc. process.
detach-inferior infno         # detaches from an inferior from assoc. process
kill-inferiror infno             # kills the process attached to the inferior. It can be removed or re-attached to some process.

Debugging Multi-threaded Programs:
    info threads    # displays thread info - thread number, thread-id, stack frame summary
    thread threadno     # make threadno as active current thread and shows stack frame summary

Starting and Stopping Multi-thread Programs
2 modes of debugging:
1) All stop mode: aka 3 musketeers mode i.e. "All-for-one, One-for-all"
2) Non-stop mode:
    set target-async on|off    # Switch asynchronous mode.
    show target-async         # Show the current target-async setting.

    interrupt    # suspend execution of the running program (whole process in all-stop, current thread in non-stop modes)
    interrupt -a    # stop the whole program in non-stop mode

The Pyramid of Knowledge

2010-10-30T04:07:00.000-07:00

Knowledge can be thought of as a Pyramid of Information, like the predator-prey biological pyramid or energy distribution in an ecosystem.

Building the Knowledge Pyramid is like a "Fox and Hounds Paper Chase" so that the Walk-The-Long-Road on the Information Trail/Path becomes much easier.

First need to categorize learning resources into 3 levels:
1) Top-Down: Solution Space - What problems does this technology address and solve?
2) Middle-Up/Down: Module level concepts like Manager code e.g. Virtual Filesystem Cache Manager, Storage Manager
3) Bottom-Up:

Search for Short-Intros materials like ppts, podcasts, pdfs, research papers, articles, blogs, videos, mindmaps, TOC
Find the Gurus in the trade and their JourneyMan followers
Subscribe to RSS Feeds to blogs by them
1) JourneyMen in the domain like Yeshawant Kanetkar who explain things well to Apprentices (WalkInThePark Pattern)
2) MasterCraftsMen in the domain like Stroustrup, Richter, Butenhof (WalkInTheForest Pattern)

0) Blogs, articles or PPTs doing a system walk-through relating how various things and flows through the system
     like "Gusatvo Duartes blogs on Operating Systems"
1) General books to get a feel for the domain and common constraints, solutions, patterns and principles
    like "Operating System Principles", "Distributed Systems: Principles and Paradigms"
2) Applied Books using APIs, Frameworks
    like"Linux System Programming", "Windows Application Programming by Richter"
3) System/Sub-System Level books describing internals of APIs, Frameworks
     like "Understanding the Linux Kernel", "MFC Internals"

Categorizing Method Applied to Information Trail:
    Follow most referred book/white-paper trail in collections like Bibliographies, Appendices, References etc.
    This method works on any of the above 3 levels,
    Example:
   Get generic Distributed domain book from amazon and follow Up/Down to higher/lower levels of Pyramid.
    "Distributed Systems: Principles and Paradigms" -> "C++ Network Programming" ->
     a) POSA2 (Basic Distributed Patterns)-> POSA3 (Resource Mgmt Patterns) - (Design Level Classics)
     b) Operating System -> "Operating System Principles" by Galvin -> "Understanding theLinux Kernel" by Bovet and Cesati
     c) Module Level Concepts -> Caching Virtual FileSystems, Remoting Patterns -> Research Papers -> Classic Books referring to the Research Papers
     d) Networking -> "Programming the Sockets API" by Stevens -> ... -> "Linux Network Internals" (Implementation Level Classics)

On a Related Note:
A Concept Map can very nicely simulate such a Tree of knowledge.
Hmmm.... kind of like the way WikiMindMap hierarchically orgranises a Wikipedia article into a tree structure. So we can do the following to convert a wiki/webpage into a concept map:
1) Use WikiMindMap to convert wikipedia article into a Freemind MindMap and export it as a .mm file
2) Use XMind to convert the .mm file into an XMind Concept Map which is shareable and editable with friends.

Howto Learn in Small Chunks - (Bite Sized Learning)

2010-10-30T04:05:00.000-07:00

Many of the curious and interested people always end up saying at one time or another....
"I've really wanted to learn more BUT I can't seem to find the time for it...."

What happens to our time, after all as someone said "God gave each one of us 24 hours".
So how is that some people seem to make so much more use of them than others?

Apart from the solid block of time allocated for our salary-paying masters what's left of them?

Waiting in queues for doctors, meetings to start, buses to show up.... these are the places we lose our free-time 24 hours.

a) The main problem is these time-chunks are fragmented i.e. the free chunks occur in-between major tasks. We need some method to connect these small fragments together
b) Mostly these free-time chunks are too small to do any significant work.
c) Sometimes we cannot predict when we'll get these free minutes/hours. So we tend to browse stuff and use up these fragments of time.

But there is a way that we can make full use of these time-chunks if we learn how to
a) Learn in small chunks by finding bite-sized activities.
b) Actively Record-What-You-Learn so that you can continue where you left off last time. This way the task switching overhead is minimized as you save your work every few minutes - kinda like saving that important file so you don't lose all your work when the computer hangs.

1) Subscribe to RSS Feeds to blogs by Gurus in the trade and their followers (WalkInThePark, WalkInTheForest Patterns)
2) Browse constantly using a phone/iPad to browse the net on idle time-chunks like waiting for the bus, doctor, queue etc.
3) Keep a book handy for power-cuts, reading on bus etc. (Make sure that it's small enough and has big letters for easy reading). StudyTheClassics to avoid wasting time on useless stuff. Amazon ratings may not be the best guide at all times. A classic is normally referenced by many books even the time-waste ones. Utilize the bibliography at the end of most books.
4) Learn Research-Techniques like Skimming, SpeedReading, Mindmapping on a book for quick outline of the book to be added in the book review.
5) Capture the essence of what you understood by taking notes a book for quick reference later.

Use the book fully -
1) Annotate the TOC with educated guesses and already known-facts gathered from Short-Intros. Peek into topics which you can't explain well to yourself or to refresh/cross-check your memory.
2) Categorize the bibliography into ShortIntros, Mid-Stuff, Adv-Stuff to build up your Knowledge Pyramid
3) Keep incrementing your blog on the topic with all resources - links, notes, thoughts, questions.
4) Keep Reviewing your blog to reduce/add TODOs:
    correct grammatical mistakes,
    add further links for later annotation,
    cleanup and reorganize information,
     re-view the gathered information with a fresh eye,
     simplify, clarify, generalize, specify, elaborate, concise information,
     split of a huge post into different blog posts
     (each post should not be more than 2 PageDowns for the reader)
5) IMPORTANT: Blog should not be a place where information goes to die but a place where it comes alive.
With each review and update it should spawn a new generation of Rise-From-The-Ashes-Phoenixes.
6) You'll be surprised to see how much you can achieve in small bites spread across time.

See Also:
How to Read A Book And Why (from bookshelved wiki)

Useful Sections of a Syntopic Learning Post

2010-10-30T04:01:00.000-07:00

0) Add a TODO section at the top for quickly scanning pending actions on the blog
1) Build the Knowledge Pyramid one link at a time.
2) Add Short-Intros: ppts, podcasts, pdfs, research papers, articles, blogs, videos, mindmaps, TOC, tutorials, sample-code, howtos,
3) Add Mid-Stuff: guides, idioms, best-practises, FAQs, Gotchas, traps-and-pitfalls
4) Add Adv-Stuff: Design-level stuff, Patterns etc.

Howto Capture Your Ideas and Knowledge into a MindMap using Freemind

2010-10-28T03:33:00.000-07:00

For some time now I’ve been using Freemind tool to make mindmaps to capture ideas and knowledge.
I was pretty happy with Freemind the opensource and free mind mapping tool.
It has some great features including exporting the mindmap into different formats - html, browsable java-applet, picture formats, flash file, pdf etc.

What I'm really trying to do is to use and leverage my blog by adding browsable mind-maps.
I've been somewhat successful in finding resources but still failing to get the last-mile work done.
Once I do this I'll be able to use mind-maps for sharing with others and allow them to edit my work too. Seems like the best bet right now is to move to wordpress plugin below:

1) There is a Free Mind Viewer plugin for Wordpress which allows read-only browsing of your mindmap file (not just an image). I’ve not been able to try it out yet though.
2) XMind converts a Freemind mindmap into a concept map. You can then upload and share it using a free XMind account. Paid accounts also allow collaboration.
3) WikiMindMap converts any Wikipedia article into a mindmap for reading it visually.(Thanks to dorai's log for this info)
4) DeliciousMind = Delicious (bookmarking) + Freemind
blainekendall.com - DeliciousMind = del.icio.us + FreeMind mindmap
https://api.del.icio.us/v1/posts/recent?count=10000

See Also:
Freemind Mindmap Embedded In Wordpress - Web Development Jobs - oDesk
WordPress › Freemind Viewer « WordPress Plugins

FreeMind Google Module/Gadget: (Requires you to have your own blog hosting)
Freemind Viewer Google Module – Rolando Garza
Dissecting the Freemind Viewer – Rolando Garza
yuriy.org: FreeMind Flash Browser Google Gadget

placingafreemindmindmapusingobjectelements - rolandog02
Embedding mind maps - FreeMind - free mind mapping software
Freemind | drupal.org
Extension:FreeMind - MediaWiki

Freemind Collaboration on Windows - FreeMind - free mind mapping software

Freemind:
Main Page - FreeMind - free mind mapping software
Download - FreeMind - free mind mapping software

Using FreeMind - FreeMind FAQ
Tutorial effort - FreeMind - free mind mapping software
Import and export - FreeMind - free mind mapping software
Accessories - FreeMind - free mind mapping software
FreeMind 0.9.0 The New Features
FreeMind 0.8.0 Features

FreeMind FAQ
After the Applet Start - FreeMind FAQ
Essays - FreeMind - free mind mapping software
Stuff - FreeMind - free mind mapping software

Mindmapping: Articles on general mindmapping concept and uses
internet mind reader - Improves your thinking with free mind map and brainstorming software
Mindmapping, concept mapping and information organisation software
Freemind combined with blogging

[Note: This is a Work-in-Progress so subscribe to RSS feed for updates]

Howto do Reverse Debugging with GDB

2010-10-27T02:56:00.000-07:00

Webinar on Reverse Debugging with DSF-GDB
This webinar introduces the new DSF-GDB debugger integration that is part of CDT 6.0. It illustrates the recent GDB additions such as Reverse debugging, Multi-Process and Non-stop multi-thread debugging.

GDB Reverse Debugging Wiki
GDB and Reverse Debugging
Presentation (PDF) on Internals of GDB Reverse Debug and Process Record Target
GDB Reverse Debugging Tutorial

[Stub] Debugging Strategies and Techniques

2010-10-26T22:42:00.001-07:00

Howto Debug with GDB

2010-10-26T22:38:00.001-07:00

Under The Hood Look At Shared and Static Libraries, Linkers and Loaders

2010-10-26T22:36:00.000-07:00

Linker Loader :
Link order of libraries ,
Link options for gcc ld,
Yolinux Tutorial on Static, Shared Dynamic and Loadable Linux Libraries,
Shared Library How-to,
How-to write Shared Libraries by Ulrich Drepper (Redhat),
Cross Platform Shared Library How-to ,
Program Library How-to,
Linkers and Loaders online downloadable book

Howto Look Inside Executables, Libraries and Object Files

2010-10-26T22:34:00.000-07:00

Object file commands :
strip,
ld,
objdump,
nm ,
objcopy,

Blog on How to Use Objdump to look inside Your Program
Unix Tools for inspecting Object files (article on LinuxJournal),
The ELF Object File Format by Dissection,
Wikipedia on Executable File Formats

Learning Python - Collection of Resources and Links

2010-10-26T11:13:00.000-07:00

Beginner:
BeginnersGuide
BeginnersGuide/Download
BeginnersGuide/Overview
HowToEditPythonCode
BeginnersGuide/NonProgrammers
BeginnersGuide/Programmers
How do I Run a Program Under Windows
PythonEditors
BeginnersGuide/Programmers (Cpp2Python.pdf)
Good Presentation by a C guy on Python features

Blogs:
Dorai's blog post on Learning Python

CookBooks:

BeginnersGuide/Programmers/SimpleExamples
Python Snippets and Recipes
Python by Example
Common programming tasks in Python
Pythonic File Searches

Using Pythonic Idioms and Style:
Definition of "Pythonic" here
Presentations:
How to Write Pythonic" code by Christopher Arndt
Presentation on "Code Like a Pythonista: Idiomatic Python" by David Goodger
Presentation on "Code Like a Pythonista: Idiomatic Python" (Crunchy Remix) by Jeff Hinrich
How to produce slides like above using Python tools

Style Guide for Python Code

My blog on Exploring the Python standard library source code

Books:
IntroductoryBooks
Python books
How to think like a computer scientist with Python
Bruce Eckel's community contributed book: Python 3 - Patterns & Idioms

Version Issues:
Python2orPython3
What's New in Python 3.0
What's New in Python 2.6
What's New in Python 2.7
Moving from Python 2 to Python3 (PDF)
Porting Code to Python 3 with 2to3
Case Study: Porting chardet to Python 3

Learning Resources:
Installing Python

MultiMedia:
Video on "Head First into Python 3"
5-minute videos on Python Capability
ShowMeDo Screencast of Python 2.5 Development on XP
Audio/Visual Talks on Python
Introduction to Computer Science and Programming (videos from MIT course)
Podcast Python411

Python3:
"What an IronPython user should know about Python 3"

Python 3 focused version of Dive Into Python
Teaching programming with Python 3

Python 3.1:
Setup
Documentation

Python2.x:

Python Tutorial
Dive Into Python
A Byte of Python
Instant Python
Download Thinking in Python (Old) by Bruce Eckel here
Python for Java programmers

Moving to Python From Other Languages
Python is not Java

MovingToPythonFromPerl
Practice Problems for Python

Reference:
Official Python website
Python Wiki
Python 2.7 FAQ
Python 2.7 Windows FAQ
Python Quick Reference
Python Language Reference manual
Python's Standard Library Reference manual
Module Index of the Python docs
Python's reply to Perl's CPAN: Python Package Index (PYPI)
Extending and Embedding the Python Interpreter
Python/C API Reference Manual

See Also:
Eric S. Raymond article on moving to Python: 'Why Python?"

MediaPacker - Utility to help pack your DVDs and CDs to the brim

2010-10-26T08:52:00.000-07:00

Media Packer is meant to solve the following problems.
1) Allow good-fit packing of DVDs, CDs with given set of directories/files.
2) Intention is to semi-automate (i.e. provide suggestions to users) or fully automate the process of packing backup media such as DVD, CDs.
3) To be developed in Python for portability and ease-of-extension

InProgress:
1) Display media space occupied by a folder structure (files and directories).
File Size code snippet,
>>> import os
>>> b= os.path.getsize("/path/isa_005.mp3")
>>> b
File I/O tutorial
>>> f = open( 'test.txt', 'at')
>>> f.writelines( str(b))
>>> f.close()
>>> f = open( 'test.txt', 'rt' )
>>> s = f.readlines()
>>> sDirectory Size Lister (Check out the comments at end of blog to get info on )

Pydirstat. pydirstat is a really handy cross-platform, command-line way to generate information about disk usage. http://developer.berlios.de/projects/pydirstat/

Future features:
1) Add catalog and search facility to uniquely identify each media, add tags for folders/files and user comments.
2) Allow collaboration and sharing of catalogs among friends to share useful files.
3) Possibly use bit-torrent protocol for the sharing??

To be released under GPL.

See Also:
MediaPacker sourceforge account

StarUml is dead (NOT)!! Long Live the Stars!!

2010-10-26T07:39:00.000-07:00

Star UML a very nice stable open-source design tool was suspected to be dead.
The tool is downloaded quite heavily, but development seems to have been abandoned as of 2005 with a stable release version 5.0.

But hey!! Just-a-minute, StarUML seems to have been rebooted as of (2010-July-19).
Originally written in Delphi, looks like its being converted to an eclipse plug-in in java.
Don't know how long it'll take to do the conversion though.
Seems like there are two(?) developers working on it right now.
Best of Luck to you.
Anybody with experience in Eclipse plugins and Java wanna help?!!!

Refer the project news and an announcement below:

Kick-off with Java-based StarUML Project

http://sourceforge.net/news/?group_id=152825

Delta Debugging

2010-10-25T21:34:00.000-07:00

References:
Download Delta from delta.tigris.org
Why Programs Fail has won a Software Development Jolt Productivity Award!
Eclipse Plug-Ins - Software Engineering Chair (Prof. Zeller) - Saarland University
DDchange - DDchangeWiki
Delta Debugging article on Wikipedia
Delta Debugging articles by Andreas Zeller

See Also:
Episode 101: Podcast with Andreas Zeller on Debugging | Software Engineering Radio

Video by Andreas Zeller on Debugging the Debugging activities
Video YouTube - Learning from Code History
Mining Software Archives by Andreas Zeller
About Andreas Zeller - S/W Engg. Chair at Saarland University

Publications by Prof. Andreas Zeller

Adv Debugging - My Program Worked Yesterday, but Not Today (WYNOT) by Andreas Zellar

2010-10-25T11:00:00.000-07:00

Brief Notes of my understanding of on Delta Debugging as discussed in “Worked Yesterday, NOt Today" by Andreas Zeller
Note: To understand the basic premise and constraints/approaches of Delta-Debugging referred to the pdf link to:

Analyse the tables/graphs carefully. (80% of the understanding comes from the example tables/graphs)
Connect the WYNOT talk with Andreas Zellar's podcast on Software Engineering Radio.

Problem: Yesterday's code works but Today's code doesn't. How do we find the change(s) which induces the test-case failure.
Context: Looking through the CVS history we find that N changes have been added since Yesterday.

Alternative: Normally we would need run the debugger to reproduce the failure and then try to collect information which induces it. But this requires a programmer to interactively query the program state using a debugger.
Can the debugging be automated without needing the programmer?

Strategy: Delta Debugging using a test-case to reproduce the failure.
Data Method:
Using the Scientific Method we can first try to reduce the Input Data in a binary search mechanism to isolate the minimum data which causes the failure.
Code Method:

Simple Method: When failure is caused by a single change. We can try to isolate the change which causes the failure by doing a binary search through the change history. If there are N changes between Y(esterday) and T(oday) we test 'k/2'th change where 1 <= k <= N. We go on partitioning until we find a failure-free change. The latest failing change is the culprit. Complexity of this binary search is O (log N)
Complex Method: When failure is caused by a combination of changes. Unfortunately it's Not always possible to use the Simple Method in the case when combination of changes cause the failure. In such a situation we need to identify at least 2 (or more) changes which together cause the failure.

Divide the change history into N changes
Group N changes into say 4 units i.e. N = N/4 * 4
Generate combinations with different units.
Test combinations for the failure.
Prune any units which don't participate in the failure at all.
Recursive above steps by sub-dividing the units above (quarters into octets and so on) until we finally we end up with minimal changes that reproduce the failure.

Proposed Plans to Reduce to Reduce Computation and Avoid Inconsistent Configurations :
a) Group related changes - changes on common date/file/variable are more likely to be related. Group them into a single unit to avoid dependency across units.
b) Prune configurations when they're obvious dead-ends e.g. Where change dependency is chained all the way (Today) 10->9->8->7->6->5->4->3->2->1 (Yesterday)
c) Exclude changed code which is never executed.

See Also:
Pdf: "WYNOT - Worked Yesterday, NOt Today"
Andreas Zeller
Podcast on Software Engineering Radio
Delta Debugging

Debugging with GDB's Cheat-Sheet of Commonly Used Options

2010-10-23T02:28:00.000-07:00

Gdb:
Compiling a program for debugging:
    g++ -ggdb -O0 hello.cpp   #
    g++ -g3 -O0 hello.cpp       # -g3 compiles debugging info for preprocessor macros and no optimization

Running a program under the debugger without arguments
$> gdb myProgram

Setting the program arguments:
   a) $> gdb --args myProgram 10 20 30 40
   b) (gdb) start 10 20 30 40 # sets temporary breakpoint at main() and calls run.
   c) (gdb) file myProgram
        (gdb) run 10 20 30 40
   d)   (gdb) set args 10 20 30 40
   (gdb) show args
        (gdb) run
    e) $> gdb myProgram core
    f) $> gdb -tui myProgram core # start vim/emacs ide for debug session
Redirect input/output of debugged program (inferior process):
    (gdb) file myProgram
    (gdb) run < input.txt > myProgram.log

    #Start debug session by Running a wrapper program to setup the environment for the debugged executable:
    (gdb) set exec-wrapper env 'LD_PRELOAD=libtest.so'
    (gdb) run

Quitting gdb:
    a) quit
    b) Ctrl-d
Displaying source code:
    list    # displays 10 lines from current point in source code
    list    # displays 10 lines of the function
   list -10    # displays negative 10 lines i.e. above current point in source code.
Printing information:
    print iCount    # prints value of iCount variable
    print $eax    # prints value in eax register
    print my_func(10+2)    # prints the return value of myFunc(12)
    printf "%s\n" myPtr    # prints the string pointed to by myPtr

Change variables:
    set iCount=100

Control-flow statements:
Setting a breakpoint:
    break main                    # set breakpoint on a function
    break myfile.cpp:10    # set breakpoint on Filename:Linenumber

    # Attach a conditional to a bnum where bnum is a breakpoint, watchpoint or catchpoint
    cond bnum x != 0

    (gdb) step [count] # step to next source level statement (includes entering into a function call)
    (gdb) stepi [count] # step to next machine level instruction (includes step-into a function call)
    (gdb) next [count] # step to next source level statement (stepping over a function call)
    (gdb) nexti [count] # step to next machine level instruction (stepping over a function call)

    # Useful for reaching a function or skipping over a loop
    (gdb) until [location]    # continue execution until you reach the location.

    (gdb) continue [ignore-count]     # continue execution with optional count to ignore a breakpoint
    (gdb) call add(10,20)   # call any function from gdb
    (gdb) finish    # finish the current function and stop in calling function
    (gdb) return    # force return to calling function
    (gdb) advance myfunc # jump to an arbitrary location in the program

Autocomplete in gdb: (Press tab at end of word or alt+?)
    (gdb) break m(TAB)
    (gdb) br 'myFun(TAB)
    (gdb) br 'myFun(Alt+?)
    (gdb) print 'mystruct.my(Alt+?)       # displays all members of mystruct
Break Command Lists:   a)break 403 if x>0      commands
        silent
        printf "x is %d\n", x
        continue
      end
    b) break myFunction
        commands
            silent
    set x = y + 4
            continue
        end


Stack frame operations:
    frame    #display brief description of currently selected stack frame
    info frame [addr] #verbose description about stack frame
    frame n    # select frame by number
    frame addr # useful to select bug-corrupted frame by address rather than frame number

    up (-)N    # move up by (-)N stack frames
    down (-)N    # move down to (-)N stack frames downward
    backtrace [full (-)N]    # show function call-stack upto N depth, Full shows locals also for current thread
thread apply all backtrace [full (-)N] # displays backtrace for all threads in a multi-threaded application.

    info args    # display arguments of current stack frame
    info locals    # display in-scope (static/auto) variables of current stack frame.
    info catch    # display info on exception handlers in current stack-frame
Automatic display of info:
    info display    # lists the various auto displays
    display /fmt expression
    disable|enable display dnum
    display    # forces output of all the enabled display-expressions
    Note: GDB automatically disables display of a local variable when it goes out of scope.

Examining Memory:
    a) (gdb) info line main
            Line 9 of "hi.cpp" starts at pc 0x000c and ends at 0x0100
       (gdb) disassemble /m 0x000c, 0x0100       # /m = mixed source+assembly, /r = raw machine instructions

    b) # n=Count, f=format (`x', `d', `u', `o', `t', `a', `c', `f', `s'), units=(byte=1, halfword=2, word=4, giant=8)
        x /10s1 &myarray    # print 10 bytes string of myarray

Attaching to a running process by PID:
    attach 1234      # attaches to external process by PID and stops it
    break myBuggyFunction     # set break point
    continue                              # continue execution of stopped process
    detach                                # gdb detaches from the running process. Can run/attach another process from hereon.

Kill the debugee process:
Note: a) If you exit gdb while you have an attached process, you detach that process.
b) If you use the run command (while attached), you kill that process.
c) By default, gdb asks for confirmation if you try to do either of these things
    kill   # useful for a) recompile while retaining breakpoints b) switch to debugging the proc's core dump

Choose Files:
1) Take symbols from a.syms, execute a.out, use core, and attach to pid 1234
    gdb -symbols a.syms   -exec a.out   -core core    -pid 1234
2) Take symbol-table from the executable, use core and attach to pid 1234
    gdb -se a.out -core core -pid 1234
3) Standalone gdb commands to choose symbol-file, exec-file , core-file:
    file progAndsym.out    # choose both symbol and executable files
    exec-file prog.out
    symbol-file symbols.sym
    core-file core.1234

 Gdb help:

    a) help command
    b) apropos search-term   # similar to apropos command to search based on search terms
    c) info # help on program being debugged
       help info #see what all commands are possible for info
    d) set radix 10
       show radix    # display current gdb settings for radix
       show          # by default displays all current gdb settings
       help show    # see what all commands are possible for show

Saving GDB command history:    set history filename fname
    set history save on|off

Running shell or make commands:
    a) shell ls
    b) make clean
       make all

Logging gdb output:
set logging on|off
    set logging file mygdb.log,
    set logging overwrite on|off    # set append on/off
    set logging redirect on|off    # redirect output to logfile AND console
    show logging    # show current logging settings

Get/Set GDB settings: # better to set/get environment variables through .profile/.login files.
    a) cd directory    # set current directory
        pwd
    b) info proc        # displays current directory of debugged process at any time
    c) (gdb) show paths
        (gdb) path directory
    d) (gdb) show environment [varname]
        (gdb) set environment varname [=value]   # set value as null if optinal value is missing
       (gdb) unset env varname

Howto Debug a Core-Dump/Crash-Dump for a stripped binary from a production machine

2010-10-19T11:16:00.000-07:00

Core dump Analysis:
core(5)– (Linux Programmer's Manual – File Formats)
Core Dump (Wikipedia)
Me mory dump (Wikipedia)
CallStack (Wikipedia),
Enabling core dumps in embedded systems,

Dr Dobbs - Postmortem Debugging
Dr Dobbs - Post-Mortem Debugging Revisited

Stackoverflow article (with comments) on core dump analysis on Solaris,
Backtrace commands in GDB documentation
Howto generate a Backtrace for Bug Reporting by Testers (from Gentoo doc)

Stack buffer overflow (Wikipedia)

Segmentation fault (SIG_SEGV, SIG_BUS)
A FAQ: User contributed answers regarding the definition of a segmentation fault,
A "null pointer" explained,
Answer to: NULL is guaranteed to be 0, but the null pointer is not?
Resolving crashes and segmentation faults,
What is the difference between a segmentation fault and a stack overflow?

Windows:
Crash dump analysis website

Books:
Debugging: The Nine Indispensable Rules for Finding Even the Most Elusive Software and Hardware Problems (by David J. Agans)
Software Exorcism: A Handbook for Debugging and Optimizing Legacy Code (by Bill Blunden)
Debugging by Thinking : A Multidisciplinary Approach (by Robert C. Metzger)
Memory Dump Analysis Anthology, Volume 1 (by Dmitry Vostokov)

Steps towards Technical Mastery

2010-10-12T05:31:00.000-07:00

How do you know if you've become a Master in your field?

Is there any method to learn things quickly in any field?
How do you avoid stagnation and mediocrity after becoming competent in your field?
How do you become a Master?

Take software for example: How do you become a Master in it?

These are exactly the questions which have been pushing me to seek answers.
Well now that I've got some kind of grip on this quest I'm able to give some of the answers.
Or at the very least point the way.

Short Answer: You'll know it when you get there!!
Long Answer: You'll see the Sign-Posts as you move towards achieving Mastery. Read on for the gory details.

If you look around you'll see that every profession or hobby has its levels of competence:
Sport: Club-side, Regional, National, Olympian
Writing: Beginner, Intermediate, Advanced, Master.
Martial-Arts: White-Belt, Brown-Belt, Black-Belt
Other Fields: Other classifications

The key is to know where you are and how to get to your goal.

Levels of Competence: These levels seem to hold true for learning any craft.

Beginner - Unconscious + Incompetent,
Intermediate - Conscious + Incompetent,
Advanced - Conscious + Competent,
Master - Unconscious + Competent

Thanks to Bob Bly's post:
The 4 levels of Marketing Competence where he talks about the same things applied in Marketing.

It's interesting to note that a master grows from Unconsciously Incompetent to Unconsciously Competent.
His insight becomes as unconscious as the beginner's lack of "sight". It has become a part of his nature.

Software:
The Software Industry too (like other arts and industries) is recognizing these levels:
Apprentice, Journeyman, Master-Craftsman.

Critical Steps to Mastery:
The book, Apprenticeship Patterns - Guidance for the Aspiring Software Craftsman,
talks about the path from Apprentice to Journey-Man, the most critical stage in your path to Mastery.
Written in simple and conversational style it does 2 important things:

Describes this journey from Apprentice to Journey-Man and,
Collects the real-life pragmatic Experience into Learning Patterns.

Applying the Patterns At Work And Play:
These Patterns are meant to guide people from beginner to higher levels.
This book uses a general learning-based approach and gives advice on usage of the Patterns.

Combinations of Patterns:
To take a non-software example:
In Chess the real value of patterns lies in using them in combinations.
To play at a Grand-Master level you first need to know:

Basics - Rules, dos and don't s.
Openings - individual patterns which help to bring all the pieces into play for both attack and defense.
Middle-Game - use combinations of Patterns to get a controlling position for the final assault e.g. Outposts, Forks and Pinned-Pieces
End-Game - finish the game in attack or defense

Similarly Apprenticeship Patterns shows how you can integrate different learning patterns into powerful combinations which double-triple the impact when used individually.

How and Why this approach works:
The Principle of 3-D vision, says that you get 2 slightly different views of the same object from your eyes. Your brain then uses these different views to generate a perception of depth i.e. 3-D Vision.

Like the distance between our Eyes - the key intention being - to increase the variety of feedback on the subject. The ideal approach would be to use a "3D Scanner" i.e. view the different facets of the subject by incrementally sampling it from slightly different angles. These pictures from Wikipedia illustrate the analogy.

Doing this however takes lots of time and effort. So a more pragmatic approach is to get enough resolution as required. Filling in the gaps can be done as and when required. Essentially this can give you a High-Definition 3D Vision - a must to achieve Mastery in your field.

Basically, you can use these Learning Patterns to setup things so as to get many slightly different angles on the same subject.
Come to think about it this must be what is known as the in-depth insight of a Master.
Where he sees the multi-faceted nature of the subject and intuitive ability to choose the best path from an infinity of possible ways.

See Also:
0) The Podcast that started it all SE-Radio Podcast Interview with Bob Martin on Software Craftsmanship
1) You can read the online version of Apprenticeship Patterns here -> Click Here.
You can interact with other readers and the authors by leaving your comments on the website.
You need to register there to get a user-name for your comments.
2) You can view my book review for Apprenticeship Patterns here -> Click Here
3) It's a long road to mastery and most of us are still at the Apprentice/Journey-Man level.
To know more about the higher aspects of craftsmanship see the book:
Software Craftsmanship:The New Imperative by Pete McBreen.
4) Found this article in my bookmarks on Patterns of Learning by Douglas E. Schmidt which got me started on the chess analogy.
5) Thanks to Wikipedia for the pictures on 3D scanning and great wiki on 3D Scanner technology here.

Readers Section:
You can use the buttons below for sharing this post with your friends.
Please give your comments:

What did you like/dislike about this article? Any suggestions are welcome.
What were the defining moments of YOUR journey towards mastery?

Basic Template with Ingredients for a Technical Blog

2010-10-07T08:04:00.000-07:00

A good Technical Blog Post follows the Law Of Retention: repetition helps Retention

Some Questions on your Blog Post:

Is your blog a frequently used resource for yourself and your readers?
Does it grow as you learn more - addressing different levels of questions?
Is it short and informative while being complete and self-contained?

Is your blog addressing The Readers Perspective?

What's in it for a Reader?
Tell 'em what you're going to Tell 'em.
Tell 'em.
Tell 'em what you just told 'em.
Further info.

Sample Blog Format: The final post may contain the following info in order of importance:

Why:

Rationale: How it will help the reader by reading this topic.
Summary: What this blog post talks about.
Audience: Type of people this post is meant for (general, students, professionals, admin, programmer)

What:

Screen-shots/diagrams/Photos/Videos which display the things in a tangible way.
Describe the basic "things" that are involved in the topic
Describe the useful/important inter-relations between the things

How:

howto configure these relations to get the necessary output
FAQs on common problems and solutions
How things work together (collected from various sources - blogs, forums, articles, books on the topic)
Source code snippets illustrating your ideas.

Reference Links: (Braindump of your browsing sessions.)

Introductions: Download sites, Tutorials, Blogs.
Detailed Info: Forum posts, Settings/Configuration notes, faqs, Howtos
References: Guides, Reference books with more in breadth and depth on different aspects of the topic.

See Also: Apprenticeship Patterns "Record-What-You-Learn" and "Share-What-You-Learn"

Understand Source Code by Reading Code and Refactoring for Maintaining Large Projects

2010-10-06T13:55:00.000-07:00

This list consists of one-liner tips to be used for easy lookup and reference.

Rewriting Code for Better Understanding (Coding Horror)

What I cannot create, I do not understand. [Richard Feynman]
"What I do not create, I do not understand."[Chris]
"It's easier to understand 600 tables than 100,000 lines of code." [PaulC on comp.databases.theory/2005]
Create a new project with blocks of code copied from old code. Refactor to reduce "old code smell"
Start refactoring by adding small tests to better understand code and act as regression tests.
Just scan through huge amounts of code till it starts making sense - "understand by constant exposure".
Create a text file to capture your understanding - briefly describe how the component works, realtions to other components, what it persists, its states, and source browsing/debugging tips you found useful.
Manually reformat a copy of the code - white space, and indented as per your personal style.

References:

Noble Art of Maintainance Programming (Coding Horror)

The Daily WTF is "a very enjoyable web site where people relate short stories about the crazy code they've worked with, usually with examples." (http://thedailywtf.com/)
On taking over foreign code

Tips for Increasing Code Readability (StackOverFlow)

Top-Down: Look for indicative class names and modules
Bottom-Up: Navigate to a feature implementation and browse/annotate to build standalone chunks of knowledge.
Use whitespace for increasing code-readability
Scan the system packages and classes looking for entities you can identify.

References:

Some tips from StackOverflow

Debug to understand basic data/control flows in source.
Add Logging/print statements to source to understand basic data/control flows in source.
Write unit tests for the code
Annotate a printout of the source.
Do code walk-through with someone knows how the code works.
Code review
Fixing bugs in source slowly exposes you to small parts of the whole source.
Going through bug histories will give you background info esp. on the "smelly parts" of source.
Refactor code to improve code quality and testability esp. regression tests.
Add annotations to a copy of the code as you push the edges of your ignorance.
Reverse engineer source to design document (needs heavy manual editing)
Get familiar with language idioms to quickly understand source code.
Make a paper Diagram of the application to understand flow and dependencies

This is a list of good tips para-phrased from Coding Horror and StackOverflow (linked) blogs and many user suggestions scattered across some of the useful comments.

Howto Start a Blog, Get Useful Blogging Ideas, Add Good Content, Reduce Effort with Tools and Keep Blogging

2010-10-06T13:11:00.000-07:00


Avoid Bloggers-Block:

After the initial burst you can't think of what to say - so the blog languishes.; A blog is short form for web-log i.e. a kind of "A log entry in your Personal Diary".; It is not meant to be a book which you publish after many many rewrites and deep thought.; Some people even have one-liners or even other peoples blogs as blog-entries.

Find an Idea/Topic:

Your idea becomes self sustaining if it's useful or matters to you or your friends.

You can organise your self-learning or teaching notes as blogs. Collect questions from people around you or from forum newbies. This way you create more knowledge for yourself and write excellent blog-posts that are useful to others.

Publish or Perish:

Publish as soon as you have a line of text on your blogs.

Drafts are the best way to kill blogs.

Use them only when you require to do some basic tidying before posting.

Even this can be done later followed by a republish.

Blog Incrementally:

Paste your current state into the blog (like saving a session of your mind a.k.a. brain-dump).

Every time some find some new useful information you just paste that into your blog-post.

Use a multiple clips clipboard manager to copy all the info you need.

The post should be written in logical manner with least gaps in the reasoning or steps

Any good links that you open in Firefox tabs can be saved for:

a) Further investigation

b) Future use

Reduce Blogging Effort:

Ideally follow 80-20% rule.

Spend 80% time spent on gathering material.

Spend 20% time spent on filling in gaps and reordering/rewriting post.

See Tools section for more details

Tools:

Currently I'm trying to reduce editing/formatting effort/time by using the following tools:; Blog Upload: Evaluating desktop client s/w's for editing and posting to blog (like ScribeFire, Windows Live Writer, SeMagic)
I've used 2-3 good desktop blogging clients: 1) ScribeFire to handle blog-editing, upload and managing of multiple accounts/blogs.
Looks to be the best option for now. 2) Kompozer is good for a basic HTML whysiwyg editor.
3) Windows Live Writer - not really used it but looks good enough for basic blog maintainence.: Blog Composing: Kompozer, CSS Stylesheets (TODO); MindMaps: XMind with Freemind (for mindmaps and concept maps with collaboration respectively); Pictures: Paintbrush Digicam for Photos, MediaWiki Free Photos; Video: InstantDemo, Jing ScreenCapture software for Demonstration Videos.
Diagrams: Diagramming s/w (To-Do): Uploading: To-Do; See Also:Basic Format for a Technical Blog

Howto Improve your Blog's design

2010-10-05T03:04:00.000-07:00

Accessibility: Does the title grab the attention of your intended audience?

Does the title have keywords used by the audience while searching google?
Does google index your blog regularly?
Push your blog updates to blog broadcastors like weblogs.com
Does your blog load up fast? Use the "Jump/Read More" feature and Optimize load time.

Retention: Is it easy for a casual browser to remember your blog and info you pain-stakingly put in?

Do's

Reduce information overload. Cluster related information into sub-topics.
Use Bloggers ReadMore feature to give readers an option to read a blog summary or read more.
Increase quick scanning of useful information - Add headings, indentation, bullets and white-space.
Reduce wordiness - Add diagrams/pictures/videos (with search-able captions).
Increase Searchability - Add content related tags to each blog post.
Increase Sharing - Add RSS feeds for your blog.Add Referral gadgets like Digg, Twitter, Facebook.
Increase Readability - Customize Template Layout to maximize content space and reduce scrolling.
Reduce confusion - Use short and clear sentences. Avoid compound sentences. Use Spell-check.
Increase Post Quality - Review your post after a gap of few days. You'll often find improvements.
Increase Blog Quality - As you improve the newer posts update older posts with newer techniques.

Don'ts

Boredom: Split long posts into short posts with title indicating continuity (e.g. Part 1 of 3)
Distractions:

            Avoid jarring Template design.
           Avoid Ads and Blinking information.
           Don't let Gadgets encroach upon content.
           Move all outgoing links to a "Reference Links" section at the bottom of each post.

Navigation: Is it easy for the casual browser to find relevant information on your blog?

Add captions to photos/diagrams/videos for enabling text searches.
Add headings, indentation, bullets and white-space for quick scanning of useful information.

See Also other posts on "Starting Your Blog":

mmap() is not the territory!! Part 2

2010-09-28T06:38:00.000-07:00

Final code at end of debugging:

bool testFileCopyWithSharedMem(const string &srcFileName, const string &destFileName)
{
    bool isCopyOk = false;
    string diffCmd = "diff " + srcFileName + " " + destFileName;
    int retval = system(diffCmd.c_str());
    cout << "system(" << diffCmd << ") returned: " << retval << endl;
    if( retval == 0 )
    {
        isCopyOk = true;
    }
    return isCopyOk;
}

int doFileCopyWithSharedMem(const string &srcFileName, const string &destFileName, size_t sharedMemSize)
{
    //int retval = 0;

    //Map SourceFile
    errno = 0;
    int srcfd = open(srcFileName.c_str(), O_RDONLY);
    if (srcfd < 0) {
        const char * causeOfError = strerror(errno);
        cout << "open() returned:" << causeOfError << " at:" << __LINE__ << " in:" <<__FUNCTION__ << endl;
        cout << "open(" << srcFileName << ") returned: " << srcfd << endl;
        return -1;
    }
    struct stat sb;
    fstat(srcfd,&sb);
    long pageSize;
    //pageSize = sb.st_size;
    pageSize = sysconf(_SC_PAGESIZE);
    errno = 0;
    char *srcFilePtr = 0;
    srcFilePtr = (char *) mmap(0, pageSize, PROT_READ, MAP_SHARED, srcfd, 0);
    if (srcFilePtr == MAP_FAILED)
    {
        const char * causeOfError = strerror(errno);
        cout << "mmap() returned:" << causeOfError << " at:" << __LINE__ << " in:" <<__FUNCTION__ << endl;
        return -1;
    }

    //Map Dest File
    errno = 0;
    int destfd = open(destFileName.c_str(), O_RDWR|O_CREAT|O_TRUNC, 0600 );
    if (destfd < 0) {
        const char * causeOfError = strerror(errno);
        cout << "creat() returned:" << causeOfError << " at:" << __LINE__ << " in:" <<__FUNCTION__ << endl;
        cout << "creat(" << destFileName << ") returned: " << destfd << endl;
        return -1;
    }
    errno = 0;
    char *destFilePtr = 0;
    destFilePtr = (char *) mmap(0, pageSize, PROT_WRITE|PROT_READ, MAP_SHARED, destfd, 0);
    if (destFilePtr == MAP_FAILED) {
        const char * causeOfError = strerror(errno);
        cout << "mmap() returned:" << causeOfError << " at:" << __LINE__ << " in:" <<__FUNCTION__ << endl;
        return -1;
    }

    ftruncate(destfd, sb.st_size);
    cout<< "PID:" << getpid() <
    //cout << srcFilePtr << destFilePtr <
    system("cat /proc/self/maps");

    memcpy(destFilePtr, srcFilePtr, sb.st_size);
    //msync(destFilePtr, pageSize,MS_SYNC);

    munmap(srcFilePtr, pageSize);
    munmap(destFilePtr, pageSize);
    close(srcfd);
    close(destfd);
    return 0;
}

----------------------------------------------------------------------------

Time required:

Debugging 1 AM to 5:40 AM.

20 Minutes to note down these points in the blog.

2 hrs to massage it into shape.

Interesting Links:

DevShed : development tutorials: http://www.devshed.com/

Gentoo Bug Reporting Guide: http://www.gentoo.org/doc/en/bugzilla-howto.xml

C sample source on Gnu/Linux : http://www.c.happycodings.com/Gnu-Linux/index.html

Mmap() security bug with Null Pointers: http://blog.ksplice.com/2010/03/null-pointers-part-i/

Wiki on Chromium multi-process debugging with gdb: http://code.google.com/p/chromium/wiki/LinuxDebugging

BugReport: http://www.mail-archive.com/ubuntu-bugs@lists.ubuntu.com/msg2333427.html

Code Review Tools

2010-09-28T06:22:00.000-07:00

Code Review Tools:
http://www.reviewboard.org/
http://code.google.com/p/rietveld/

Sample Review and Analysis of DVCS (Git/Mercurial) in Python Enhancement Proposals:
http://www.python.org/dev/peps/pep-0374/

Push your blog to google for indexing

2010-09-28T05:57:00.000-07:00

Manually suggest your blog to google for indexing/crawling:
http://blogsearch.google.com/ping

Refer this site for further info on getting your blog indexed:
http://www.google.com/support/blogsearch/?hl=en#getlisted

mmap() is not the territory!! Part 1

2010-09-28T05:51:00.000-07:00

(OR) how MAP_FAIL, SIGBUS,

beg to differ with mmap!!
Wrote a small program using mmap() to copy a fromFile.txt to toFile.txt using virtual memory

--------------------------------------------
Issue#1: mmap() returns MAP_FAIL
mmap() requires exactly the same flags as the filedescriptor/fd as when it was open()/creat()-ed
i.e. if you used O_RDONLY in open() then you can't mmap() it as PROT_WRITE.

chmod basics: http://www.linux.org/lessons/beginner/l14/lesson14b.html
creat/open man page: http://linux.about.com/od/commands/l/blcmdl2_open.htm
-------------------------------------------------
Issue#2:
Error Message: In gdb getting SIGBUS with error coming from inside memcpy!!

108 memcpy(destFilePtr, srcFilePtr, pageSize);
5: pageSize = 14
4: destFilePtr = 0xb7ffc000

3: srcFilePtr = 0xb7ffd000 "hello, world\n\n"
2: destfd = 6
1: srcfd = 5
(gdb) n

Program received signal SIGBUS, Bus error.
__memcpy_ia32 () at ../sysdeps/i386/i686/multiarch/../memcpy.S:75
75 ../sysdeps/i386/i686/multiarch/../memcpy.S: No such file or directory.
in ../sysdeps/i386/i686/multiarch/../memcpy.S

Searching on this gave no direct answers on the error message but gave some pointers on causes.

Tried all the below tools but still getting the same error message:

0) used apt-get update and rebooted "just-in-case"

https://help.ubuntu.com/8.04/serverguide/C/apt-get.html

1) used strace ./file-copy-vm to check the system calls were getting called properly.

getting SIGBUS on write() ostensibly called from inside the memcpy

2) used ldd ./file-copy-vm to check that the libstdc++ - and libc.so were existent.

They were present

3) Installed glibc-dbg and libstdc++-devel etc for debugging the library.

No change.

Finally found the problem in an off-by-N error in memcpy(dest,src, pageSize)

Since SIGBUS comes when a page worth is allocated but size of mapping is less than pagesize.

i.e. the accessed address is more than filesize but inside pagesize.

So realized my mistake and changed:

memcpy(destFilePtr, srcFilePtr, pageSize); //WRONG.

Corrected it to:

memcpy(destFilePtr, srcFilePtr, sb.st_size); //Correct

------------------------------------------------------------------------------------------------------------------
Issue#3: Still getting SIGBUS from memcpy() AND

out of bounds>

Breakpoint 3, doFileCopyWithSharedMem (srcFileName=..., destFileName=..., sharedMemSize=8192) at ../src/file-copy-vm.cpp:104
104 cout<< "PID:" << getpid() <
4: destfd = 6
3: srcfd = 5
2: srcFilePtr = 0xb7ffd000 "hello, world\n\n"
1: destFilePtr = 0xb7ffc000

0xb7ffc00 out of bounds>

(gdb) n
PID:7136
106 system("cat /proc/self/maps");
4: destfd = 6
3: srcfd = 5
2: srcFilePtr = 0xb7ffd000 "hello, world\n\n"
1: destFilePtr = 0xb7ffc00

0xb7ffc00 out of bounds>

(gdb) shell cat /proc/7136/maps
[SNIP]
08048000-0804a000 r-xp 00000000 08:01 933913     /home/gurud/cdt-linux-tools-workspace/file-copy-vm/Debug/file-copy-vm
0804a000-0804b000 r--p 00001000 08:01 933913     /home/gurud/cdt-linux-tools-workspace/file-copy-vm/Debug/file-copy-vm
0804b000-0804c000 rw-p 00002000 08:01 933913     /home/gurud/cdt-linux-tools-workspace/file-copy-vm/Debug/file-copy-vm
0804c000-0806d000 rw-p 00000000 00:00 0          [heap]
b7fec000-b7fee000 rw-p 00000000 00:00 0
b7ffb000-b7ffc000 rw-p 00000000 00:00 0
b7ffc000-b7ffd000 rw-s 00000000 08:01 933725     /home/gurud/cdt-linux-tools-workspace/file-copy-vm/Debug/toFile.txt
b7ffd000-b7ffe000 r--s 00000000 08:01 933672     /home/gurud/cdt-linux-tools-workspace/file-copy-vm/Debug/fromFile.txt
b7ffe000-b8000000 rw-p 00000000 00:00 0
bffeb000-c0000000 rw-p 00000000 00:00 0          [stack]

Hmmm... here the destFilePtr seems to be pointing to the correct memory-mapped file i.e. toFile.txtThe destFilePtr

is pointing to out-of-bounds accesss.

Also the SIGBUG seems to suggest that I'm trying to write/access to an address in memory that's allocated but out of bounds of the empty dest file. Otherwise I'd have got a SIGSEGV if the memory had not been allocated.

I observed that toFile.txt is showing filesize as zero on the disk. Aha!!

Robert Love in his book "Linux System Programming" had mentioned files with slack-space/holes (in memory as well as disk respectively). Could this be the reason??!!

http://www.devshed.com/c/a/BrainDump/Using-mmap-for-Advanced-File-IO/

Finally I cross-checked my code with a sample implementation for mmap() file copy program.

Found out that they used lseek() to expand the memory mapping instead of ftruncate() to expand file size with a hole instead of ftruncate().

http://www.c.happycodings.com/Gnu-Linux/code6.html

So we just need to increase the size of the dest-file using ftruncate.

(gdb) help call
Call a function in the program.
The argument is the function name and arguments, in the notation of the
current working language. The result is printed and saved in the value
history, if it is not void.

(gdb) call ftruncate(destfd,sb.st_size)
$1 = 0

doFileCopyWithSharedMem() returned:0
system(diff ./fromFile.txt ./toFile.txt) returned: 0
testFileCopyWithSharedMem() returned:0

(gdb)

Hurray!! the unit testcase passes!!
It's 6 AM!! Tiring but worth it!! Gotta go and sleep now

----------------------------------------------------------------------------

Creating a CHM file from offline/mirrored HTML pages

2010-09-27T06:07:00.000-07:00

Having too many saved/offline html folders, maybe created using Httrack like website-mirrorring software?
Storing and using these is a bit of a headache.

All you need is to convert these loose files into a compressed html file i.e. CHM file
with facilities like indexing, favorites etc.

Step 1: Install chmProcessor from http://sourceforge.net/projects/chmprocessor/. It's free to download.

Step 2: Install HTML Help Workshop if it's not already installed on your windows system

Step 3: Point chmProcessor to the HTML Help Compressor using File > Settings menu option

Step 4: Point chmProcessor to
a) the "Source File" i.e. the index.html file,
b) "Add Directory" for the directory containing the rest of the html files and
c) "Compile Help" directory to place the output .chm file

Step 5: Click "Generate" button to get the .chm file.

Gotchas: Common mistakes are to forget change the output path from one project to another.

List of useful packages for C/C++ development on Ubuntu Linux Part 2

2010-09-24T06:26:00.001-07:00

[SOURCE-ANALYZERS]
apt-get install -y exuberant-ctags
apt-get install -y doxygen doxygen-gui
apt-get install splint #Static analyzer Lint for C programs
apt-get install colorgcc #Colorizer for GCC errors/warnings
apt-get install cppcheck #C/C++ source static analyzer
apt-get install cscope #C/C++ source code browsing/searching
apt-get install cbrowser #browser for cscope
apt-get install cflow #Displays control flow graphs for C source
apt-get install cutils #Various C source code utils - cdecl, cobfusc
apt-get install cxref #Generate HTMl doc for C source code
apt-get install global #Global search/browse C++ source code
apt-get install id-utils #Identifier database used by global for search/browse C++ source code
apt-get install synopsis #C++/Python source code introspection tool
apt-get install gccxml #GCC source code described as xml
apt-get install gobject-introspections #Extract introspection data from libraries
apt-get install explain #Helps explain system call errors after the fact
apt-get install fhist #File history, compare and merge utility
apt-get install fastdep #Generates dependency info as makefile rules for C/C++
apt-get install eresi #Reverse Engineering, instrumentation, debugging, tracing framework
apt-get install evarista #Program transformer and data-flow analyzer for binaries using ERESI
apt-get install frama-c #GUI to combine multiple analyzers for C source code
apt-get install frama-c-base #Framework to combine multiple analyzers for C source code

apt-get install gnulib #Make programs portable using C macros/assertions/declarations/definitions
apt-get install gperf gperf-ace #Generate perfect hash given input strings
apt-get install gsoap #Web service stub/skeleton generator for C/C++ code
apt-get install kodos #GUI to debug, test and view regexps
apt-get install visual-regexp #GUI in TCL to debug, test and view regexps

[BEAUTIFIER]
apt-get install astyle # C++ source code beautifier
apt-get install indent #Beautifier for C Source code
apt-get install bcpp #C++ Source beautifier
apt-get install kwstyle #Ensure source code style of many people is same as one person
apt-get install uncrustify #C++ beautifier highly configurable
apt-get install unifdef #Remove #ifdef sections from source
apt-get install universalindentgui #GUI to configure and compare multiple beautifiers esp. for C++
apt-get install xmlindent #XML beautifier

[COMPILATION]
apt-get install distcc #distributed compiling
apt-get install distcc-pump #distributed preprocessing
apt-get install ccache #compiler cacher
apt-get install distccmon-gnome #GTK+ GUI to monitor distcc
apt-get install icecc #Distributed compiling
apt-get install icecc-monitor #GUI for monitoring Distributed compiling
apt-get install boost-build #Easy Cross-platform compilation
apt-get install gdc # D language compiler
apt-get install bison++ #C++ source generator enhancement to bison
apt-get install flex
apt-get install antlr3 #create compilers/interpreters using ANTLR

[LIBRARIES]
apt-get install libasio-dev libasio-doc #Cross Platform Boost library for Async IO (network programming)
apt-get install libclthreads-dev libclthreads-doc #POSIX threads C++ library
apt-get install libcorelinux libcorelinux-examples #Converting Linux core C libs to C++ libs
apt-get install libdar-dev #Disk archiver
apt-get install uc++ uc++-doc uclibc uclibc-source #Embedded C++ with multi-threading etc.
apt-get install witty-dev #AppServer and library for C++ web-deployment

[JAVA]
apt-get install gwis #C++ wrapper class generator to call Java objects/methods.
apt-get install jaranalyzer #Dependency management utility for jar files
apt-get install jclassinfo #Reads class files to get useful info from them
apt-get install jflex javacc #Flex and Bison for Java
apt-get install junit junit-doc #Unit testing for Java
apt-get install testng #NG unit testing with extra and best-of-breed features of JUnit and NUnit
apt-get install tijmp jmp #Java memory profiler
apt-get install visualvm #Tool for remote-admin, monitoring(dumping), profiling production/dev code, bug-reporting

[DATABASE]
apt-get install sqlite-database-browser #GUI for SQLite dbs.
apt-get install sqlrelay-dev #SQLite C/C++ APIs for proxying speeding up access to N DBMS
apt-get install unixodbc-dev #Unix port of ODBC

[XML]
apt-get install xmlcopyeditor #XML util for xsd, dtd, xslt, validation and syntax highlighting
apt-get install xsdcxx #Generate C++ classes from XSDs
apt-get install xml-rpc-api2cpp #Generate C++ wrapper classes for XML-RPC API

Howto subscribe to this (and other) RSS Feeds.

2010-09-24T06:21:00.001-07:00

RSS feeds push the blog content to you, instead of you having to check for updates to the site.
All this from within your browser or RSS feed client s/w.

You can very simply subscribe to any of the below options:

The whole blog, (or)
Individual blog-posts, (or)
Even just the comments part of the blog.

Howto:

0) Just use the newly added gadgets at top of the blog:

Subscribe to: Posts Comments

1) If you're using Firefox just click on the Orange Icon in your address-bar.
And choose which folder to save your "Live Bookmark"/RSS feed into.
Howto subscribe to RSS feeds in FireFox in seconds: http://johnbokma.com/firefox/rss-and-live-bookmarks.html

2) You can also use the below URLs:

RSS 2.0: http://techtalkies.blogspot.com/feeds/posts/default?alt=rss
Atom 1.0: http://techtalkies.blogspot.com/feeds/posts/default

3) Also Rss feeds to subscribe to blog comments can be found at the bottom of the blog:
"Subscribe to: Posts (Atom)"

Reference Links:

Video Tutorial in Plain English: http://www.commoncraft.com/archives/000528.html
Wikipedia: http://en.wikipedia.org/wiki/RSS
Check out which one to use in What is Atom? How does it Compare to RSS?

Why write technical blog posts Part 2

2010-09-24T06:10:00.000-07:00

Some interesting quotes (with links) from "Apprenticeship Patterns":

Section 6: Construct Your Curriculum

" the vast amounts of wisdom captured in the books of experienced practitioners like Jerry Weinberg, Fred Brooks, Steve McConnell, and Kent Beck cannot be replaced, not even with higher-bandwidth information. Even if you’re not a bookworm, a successful apprenticeship needs to include some books as well as time devoted to studying. You’re not in school, though. There is no assigned reading—it’s up to you to find recommendations and construct your own curriculum."

0) Reading List
          "Problem:
                   The number of books you need to read is increasing faster than you can read them.
        Solution:
                Maintain a Reading List to track the books you plan to read, and remember the books you’ve read."

1) Study the Classics:

"Joshua Kerievsky once asked Jerry Weinberg how he keeps up with all the books that come out. Jerry said, “Easy—I only read the great ones”
[...]

"Successful apprentices tend to focus on “long-lived books” and use the Web or experimentation to learn how the information has evolved. Dave remembers vividly the experience of reading his first classic in this field, The Psychology of Computer Programming, and marveling at how relevant the book felt, despite the stories of punch cards and room-sized computers. The wisdom captured in such classics is vital information to keep you heading in the right direction on The Long Road."

2) Dig Deeper:

"Problem:

You keep running into difficulty maintaining the code you’ve written because it turns out that the tutorials you followed cut corners and simplified complex issues. You find that your superficial knowledge of a thousand tools means you’re always floundering whenever a subtle bug arises or you have to do something that demands deep knowledge. People often accuse you of having a misleading CV because you don’t distinguish between a couple of weeks of extending an existing web service and a deep knowledge of the issues inherent in maintaining an interoperable and highly scalable enterprise system. What’s even worse is that because your knowledge is so superficial, you’re not even aware of how little you know until something or someone puts you to the test.

Solution:

Learn to dig deep into tools, technologies, and techniques. Acquire the depths of knowledge to the point that you know why things are the way they are. Depth means understanding the forces that led to a design rather than just the details of a design. For instance, it means understanding type theory (or at least the simplification offered by the typing quadrant at http://c2.com/cgi/wiki?TypingQuadrant) rather than simply parroting the things you’ve heard others say"

List of useful addons for FireFox (with links) Part 2

2010-09-24T06:06:00.000-07:00

List of useful addons for FireFox (with links) Part 1

Note: These addons have been added on Firefox version 3.6.10

+ScribeFire Blog Editor

Description: Edit and post your blog from inside firefox with this plugin.
Note: ScribeFire Next is a bit buggy i.e. publish button disappears too fast to click.

Download: Add to Firefox

+ DownThemAll

Description:
The first and only download manager/accelerator built inside Firefox!
Download: Add to Firefox

+ Easy YouTube Video Downloader

Description:
Easiest Youtube video downloader ever, single click non-intrusive direct download buttons for FLV, 3GP, MP3, MP4, 720p HD and 1080p Full-HD qualities.
Download: Add to Firefox

+ NetVideoHunter Video Downloader

Description:
Download videos and music from video sites like Youtube.
Download: Add to Firefox

+ ImgLikeOpera

Description:
ImgLikeOpera allows load only the images that you want in Firefox browser. This extension is very useful for non broadband users...
Download: Add to Firefox

Not available for Firefox 3.6.

+ SessionManager

Description:
Session Manager saves and restores the state of all windows - either when you want it or automatically at startup and after crashes. It can also automatically save the state of open windows individually.
Download: Add to Firefox

+ SpeedDial

Description:
Direct access to your most visited websites
Download: Add to Firefox

+ WOT - Safe Browsing Tool

Description:
Would you like to know which websites you can trust? The WOT add-on is a safe surfing tool for your browser. Traffic-light rating symbols show which websites you can trust when you search, shop and surf on the Web.
Download: Add to Firefox

[BOOKMARKS]
+ TagSieve (Note: This has NOT been reviewed by Mozilla)

Description:
This is a continuation of the excellent but abandoned TagSifter extension.
Firefox lets you tag your bookmarks, but it doesn't give you a great way to browse your bookmarks by their tags.
Download:

+ Xmarks Sync (NOTE: Xmarks is SHUTTING DOWN. Don't use it.
This will backup your ALL bookmarks so DON'T use for official links)

          Description:
          Xmarks is the #1 bookmarking add-on.
          Keep your bookmarks, passwords and open tabs backed up and synchronized across computers
          and browsers. Search smarter with website ratings and reviews displayed with your search results.

          Download: Add to Firefox

+ Firefox Sync by Mozilla Labs
    Description:
    Free browser add-on that lets you stay in sync with your Firefox.
    Access your history, passwords, bookmarks and even open tabs across all your devices.
    Download: Add to Firefox

+ Bookmarks Duplicate Detector

Description:
Detects Duplicate Bookmarks when bookmarks are added and specify where is the previous URL. You can also search and delete duplicates URL already in your Bookmarks.
Download: Add to Firefox

Not available for Firefox 3.6.10

WikiSeer Keynotes

Description: WikiSeer Keynotes finds the most significant content in any English web page; shrinking the original up to 99%. It serves as a middle ground between skimming the titles and reading the entire article, providing a faster / richer reading experience.
Download: Continue to Download →

Lazarus: Form Recovery

Description: Never lose anything you type into a web form again! Lazarus securely auto-saves all forms as you type, so after a crash, server timeout, or whatever, you can go back to the form, right click, "recover form", and breathe a sigh of relief
Download: Add to Firefox

Reframe It

Description: Commenting tool to add comments right next to Web pages without permission and share with others.
Download: Continue to Download →

DejaClick

Description: Record and bookmark your browser activities, then with a single click, replay the entire sequence all over again.
Download: Add to Firefox

FloatNotes

Description:
With this add-on you can put notes anywhere on a website. Add comments, links or even images. It can help you doing research on the web, remind you of topics you want to blog about, etc. It is simple and easy to use.
Download: Add to Firefox

Utils for Linux and Windows

2010-09-24T05:59:00.000-07:00

Search Everything:
This is a really fast and compact file search utility for windows. It beats Google desktop hollow if all you need is to search file/directory names. Already its saved me from re-downloading stuff, finding work that I’d stored away (safely!!) somewhere and just plain discover that I’ve got more goodies on my system than I’d thought!!
Having a huge HDD (by today’s standards) 1 GB does help to keep useful stuff ready for “Search Everything”.
Some nifty features to add would have been
1) Search inside compressed files and maybe
2) Catalog generation for offline media like CDs/DVDs.

Bharat has written a nice blog post on it called "Search Everything – A wonderful utility to reduce file searches".

Recently reinstalled Windows/Ubuntu and had to reinstall all the stuff.

I was using the old blog editor in blogger and managed to lose nearly 75% of a blog.
No undo function to revert to previous version of my blog. Searched for a work-around in blogger.
Nearly 3 hours of hard-work gone down the drain.
Found these GUI utilities for Ubuntu and Windows to hold ALL copy-paste stuff from the clipboard.

1) Glipper the multiple copies clipboard manager on Ubuntu Gnome Desktop

#a) Installs Glipper the multiple copies clipboard manager into Ubuntu Gnome Desktop
apt-get install glipper
#b) Right click on the "Windows Quicklaunch Bar" and Add to Panel->Clipboard manager
#c) Click on any of the previous copies to get the copy-paste you need.

2) Nautilus elementary -> Elegant Gnome. Making the desktop look neat.
     http://gnome-look.org/content/show.php/Elegant+Gnome+Pack?content=127826
     (Found it from somewhere inside http://lifehacker.com/tag/linux/!!)

3) Also Clipboard Manager for Windows for extending the basic Windows clipboard.
      http://space.dl.sourceforge.net/project/clipman/Clipman/v1.0/ClipMan_Setup.msi
      Note: May require .net framework 2.0.50727 to run if it's not already installed.
      Easily downloadable from this site

Why write technical blog posts Part 1

2010-09-24T03:57:00.000-07:00

Technical blogs help to:

Record and speed-up the process of learning a new topic.
Can be used as learning devices.
Provide a useful format for note-taking as you learn new things.
Sharing and growing knowledge with others.
Provide invaluable feedback necessary for your own growth.
Capture the essence of what you learned during research

Technical blogs should evolve from one-liners to concise researched posts.
They should act as brain-dumps of all your research.

Research is a frightfully expensive activity with loads of context building up as you search.
What happens after to all this invaluable context after you spend a week or more researching it?
It evaporates within days of research as you move on to other things.

The beginners mind full of questions is an invaluable resource.
Unfortunately it's impossible to retain as you learn more and more!!

Slowly the questions give way to answers...
Only for more questions to pop-up... with answers following slowly.
The mystery thickens fast as you try to satisfy your quest for understanding.

Researching, reading books, articles, blogs that you browse on the Net, experimenting, theorising, modelling.
All these go into the steaming cauldron of your quest....

Slowly the mists part to slowly yield insights into what makes the thing tick!!

Writing and Revising your blogs is a definite way to nurture and match this process of growth.
The very process of writing simply and clearly forces you to seek out the core of the concept.
This is THE most valuable gift to the technical blogger - fuelling his own growth while helping others on the path.

Innocence yielding to Experience yielding (very) slowly to Mastery.

Not only does it capture the questions and answers you found.
It can very easily form the basis for helping out someone on the same path.

All this started when one of my friends mailed me asking me how come I was suddenly referring to so many books and all suddenly?
I realised that the actual query was more like:
1) Why are you writing so many Tech-Info posts all of a sudden?
2) Whats with the constant chanting of "Apprenticeship Patterns" mantra?

By the way for those who are new to this stuff:
Apprenticeship Patterns is a print/online book which describes the long journey of a Master Craftsman.
The Looong journey from Apprentice to JourneyMan to Master.

One of the activities of a good apprentice is to "Construct Your Curriculum", This involves the related patterns

Build up a Reading List over time
Study the Classics:
Dig Deeper
Record What You Learn
Share What You Learn (hence these blog posts)

It is not humanly possible to read ALL these books in such a short time esp. as they're meant to be reflected upon and applied to your specific situation.

This is just compiling a Reading List. Filtering into a Classics-only list will have to wait a few days.

These posts are just for future use (Record What You Learn).
And maybe a resource for like-minded people out there.
People with the same problems, questions and wanting answers from the masters of the programming world.

Actually I'd found these books about 2 years back but only had a mental todo book list.
It's too much "wasted-time and effort"..... UNLESS it saves you time and effort in the long run.

The Genius of Jerry Weinberg - The Psyche of Programming

2010-09-24T00:40:00.000-07:00

Gerald (Jerry) Weinberg - The Programmer Psychologist, Writer, Systems Thinker:
http://www.geraldmweinberg.com/Site/Home.html

http://www.geraldmweinberg.com/Site/Books.html

This guys papers, articles and books on "Helping Smart People be Happy" are quoted on books by most of the Experts in any domain of programming.
Check out his articles/books: All books written by Gerald Weinberg on Amazon

See below for customer reviews on Amazon:

Amazon Customer Reviews/Comments on Jerry Weinberg's books:
The Classic :

The Psychology of Computer Programming: Silver Anniversary Edition

Guide for Interviewers and Interviewees:

Hiring The Best Knowledge Workers, Techies & Nerds: The Secrets & Science Of Hiring

Problem Solving (useful for OnTheJob and Interviews too):

Are Your Lights On?: How to Figure Out What the Problem Really Is

Guide for Technical Leaders:

Becoming a Technical Leader: An Organic Problem-Solving Approach

Guide on becoming a Consultant:

Secrets of Consulting: A Guide to Giving and Getting Advice Successfully

Know Thyself:

Understanding the Professional Programmer

Systems Thinking:

Systems Thinking: General Principles of Systems Design

Mindmap of my observations/experiences in "Apprenticeship Patterns Applied"

2010-09-23T13:34:00.000-07:00

How to find an answer to (some) of your questions - in Life, the Internet and Other Forums ;-) !!!

2010-09-23T12:38:00.000-07:00

Learning to Learn (lessons from the lab)

How to Read a Book (Amazon)
How to Read a Difficult Book (Article)

Heuristics and Problem solving
+ How To Solve It
+ How To Solve It By Computer

+Asking Questions to Solve Problems on Internet Forums:
+ Get Connected section of "How to do Research at MIT AI Labs"
+ "How to Ask Questions the Smart Way (on forums)"by Eric S. Raymond
Questions NOT to ask
Examples of Good and BAD questions
Do Your Homework/Due Diligence
When You Ask
If You Can't Get An Answer
Dealing With Rudeness

+ Collected Advice on Research and Writing
+ Brief advice on How to sift through research papers in your domain

List of useful addons for FireFox (with links) Part 1

2010-09-21T08:04:00.000-07:00

Addons for firefox (3.6.10)

+ Pixlr Grabber

Description: Making screen grabs and pulling down images from the web just got a bit more easy. With the Pixlr grabber add-on you can choose to Edit, Share, Save or Copy your final grabs. You also get the possibility to right-click any image or background to edit
Download: Add to Firefox

+ ClickCutter AutoCopy

Description:
Highlight a text and automatically Copy it to the clipboard.

Based on unique Smart Autocopy technology!
You have full control of what to copy and what not to copy when you highlight text.
Middle button Paste option.
Super-easy.
Download: Add to Firefox

+ ClickCutter AutoSearch

Description:
Highlight text and AUTOMATICALLY SEARCH it in your favorite search site.

Includes:
- Automatic Copy of highlighted text (AUTOCOPY)
- Automatic websearch for highlighted text (AUTOSEARCH).
- Middle button Paste
NO annoying context menus !
Download: Add to Firefox

+ Lizardtech DjVu (Many rare ebooks are available in this format)

Description:
DjVu is a web-centric format and software platform for distributing documents and images. DjVu can advantageously replace PDF, PS, TIFF, JPEG, and GIF for distributing scanned documents, digital documents, or high-resolution pictures. DjVu content downloads faster, displays and renders faster, looks nicer on a screen, and consume less client resources than competing formats. DjVu images display instantly and can be smoothly zoomed and panned with no lengthy re-rendering. DjVu is used by hundreds of academic, commercial, governmental, and non-commercial web sites around the world.
DjView4 is a new portable DjVu viewer and browser plugin.
Download:
http://djvu.sourceforge.net/

+ All In One Gestures

Description:
This extension allows you to execute common commands using mouse gestures, rocker navigation, scroll wheel navigation and page..
Download: Add to Firefox

+ All In One Sidebar

Description:
AiOS lets you open various windows as sidebar panels, and quickly switch between them. So it put an end to the window chaos! In addition to bookmarks and history it opens dialogues such as downloads, add-ons and more in the sidebar.
Download: Add to Firefox

+Wikipedia Lookup Add-on

Description:

Looks up up the selected word in the Wikipedia encyclopedia in the language specified in your user preferences.
Download: Add to Firefox

+ CHMReader

Description:
An extension to make firefox support Compiled HTML(.chm) file.
Download: Add to Firefox

+ ClipMarks

Description:
Clipmarks lets you clip and share specific parts of articles, blog posts or anything else you read on the web. With our newly integrated Amplify service, you can post clips directly to Twitter or Facebook - or share them on clipmarks.com and more.
Download: Add to Firefox

+ ColorfulTabs

Description:
The most beautiful yet the simplest add-on that makes a strong colorful appeal. Colors every tab in a different color and makes them easy to distinguish while beautifying the overall appearance of the interface. For Seamonkey & Flock. An essential.
Download: Add to Firefox

List of useful packages for C/C++ development on Ubuntu Linux Part 1

2010-09-21T04:45:00.000-07:00

Linux in a Nutshell: A superb bible for looking up Linux commands and options. http://oreilly.com/catalog/9780596154493

Installing Development related packages on Ubuntu:
http://software.jessies.org/salma-hayek/ubuntu-setup.html

You can add repositories to download packages by editing this file:
vim /etc/apt/sources.list

For Eclipse C++ CDT installation please refer to this blog post.

Script:
A very useful command to record your command-line session actions for later use and replay later:
        script -a -f -t 2> timingfile mydemo.log     #append, flush-writes, timestamp)

       scriptreplay timingfile mydemo.log    #replays with timing as per timestamps captured above
For further info see:

     man script
     man scriptreplay

Links:
http://www-users.cs.umn.edu/~skim/cs1901/script.html
http://devdaily.com/blog/post/linux-unix/use-unix-linux-script-command-record-your-command-line-i-o

Killing Processes on Ubuntu with 3 Finger salute(How-to-Geek)

gpm: A command-line text mode clipboard manager with mouse integration.
Use left mouse button to select and copy text and paste with middle mouse button.
Super useful installation/usage howto from Gentoo: http://www.gentoo.org/doc/en/gpm.xml#doc_chap4

gpm options: http://www.oreillynet.com/linux/cmd/cmd.csp?path=g/gpm

apt-get install -y gpm #General Purpose Mouse server (clipboard manager for command line
NOTE: You can set the system default packages on Ubuntu using debconf-set-selections and debconf-get-selections

Glipper: Clipboard manager for Gnome. It retains all your text copies.

I went through the entire list of packages available and selected a few below from the Development (meta-package?) of Ubuntu (10.04.1 ubuntu desktop 32 bit)

[COMMON-DEV]
apt-get update #updates your packages

apt-get install -y gcc #GNU C compiler

apt-get install -y gcc-mingw32 #Cross Compilation
apt-get install -y g++

apt-get install -y make
apt-get install -y linux-headers-`uname -r` build-essential #C/C++ header files for building C/C++ programs
apt-get update eclipse eclipse-pde #Update Eclipse and plugin-dev-env for connect to p2 repository of CDT for installing the CDT

apt-get install -y vim-gtk

apt-get install -y c++-annotations
apt-get install -y c-cpp-reference #Reference for C/C++
apt-get install -y cpp-doc #C++ documentation
apt-get install -y manpages-dev glibc-doc

[PACKAGE-MGMT]
apt-get install -y apt-build #GUI for apt-get
apt-get install -y ceve #Parse linux package dependencies

[PYTHON]
apt-get install -y python-dev
apt-get install -y idle2.6
apt-get install -y cableswig #Python/Tcl wrappers for C++ code
apt-get install -y boa-constructor #RAD tool for python/wxwidgets

[PROFILERS]
apt-get install -y gprof
apt-get install -y kprof #KDE util for gprof analysis/viewing
apt-get install -y valgrind
apt-get install -y cachegrind
apt-get install -y alleyoop #Valgrind related
apt-get install -y valkyrie #GUI for valgrind
apt-get install -y kcachegrind #KDE Gui for valgrind
apt-get install -y sysprof #System-wide CPU profiling
apt-get install -y systemtap systemtap-client systemtap-grapher #Collect data on a live running linux box
apt-get install -y syslog syslog-ng #Interprocess application logging facility

[TESTING]
apt-get install -y libcppunit-doc libcppunit-dev #C++ unit-testing lib

apt-get install -y subunit #Run and Save remote test results for later use
apt-get install -y stress #Stress test your computer with heavy load
apt-get install -y httest #Simulate client/server actions with pattern-matching for test validation
apt-get install -y fuzz #Stress test s/w with random inputs

[DEBUG]
apt-get install -y gdb gdb-doc #Debug programs
apt-get install -y gdbserver #Remotely debug from another system where GDB is installed.
apt-get install -y ddd #GUI for gdb
apt-get install -y bashdb #Bash debugger
apt-get install -y zshdb zsh-dbg #debugger and debug symbols for ZSH
apt-get install -y gcov #Source code coverage analyzer
apt-get install -y ggcov #GUI for gcov Source code coverage analyzer
apt-get install -y lcov #HTML and directory-wise view of gcov output

apt-get install -y collectd-dbg #statistics collection and monitoring daemon
apt-get install -y wireshark wireshark-dev #Network debugging
apt-get install tack-dbg #Diagnostic tool for correctness of terminfos.
apt-get install -y tau tau-racy tau-examples #Multithread/multiproc tuning and analysis with GUI
apt-get install -y leaktracer #Simple C++ leak tracer
apt-get install -y electric-fence #malloc debugger
apt-get install -y duma #Fork of electric-fence library with added features
apt-get install -y winpdb #GUI debugger for Python
apt-get install -y gtkparasite #Python interactive debugger for running GTK+ code.
apt-get install -y happycoders-libdbg-dev #allows modern debugging paradigms for Large codebase
apt-get install -y happycoders-libsocket-dev #
apt-get install -y bless-hex-editor #Hex Editor
apt-get install -y hexdiff #Visual hex difference analyzer
apt-get install kompare #diff and merge util for files and dirs.
apt-get install -y tkdiff #diff/merge util in TK
apt-get install -y ht #Viewer/Editor/Analyser for all kinds of executables.
apt-get install -y abi-compliance-checker #C++ sharedlib binary compatibility checker
apt-get install -y tesq #Decoding of terminal escape sequences used by Unix Terminals

Installing Eclipse C++ CDT with Linux Tools for debugging and profiling applications on Linux

2010-09-20T08:32:00.000-07:00

The Eclipse incubation project Linux Tools integrates C/C++ Development tools.
It's a GUI plugin to integrate tools like Valgrind, GProf, GCov, SystemTap etc into the Eclipse C++ CDT IDE.

[Articles on Linux Tools]

IBM DeveloperWorks (search for Linux Tools)
RedHat Article

Download page of Eclipse Helios gives 2 good alternatives for C++ developers on Linux:

Download Eclipse IDE for C/C++ Developers, (87 MB) without LinuxTools

Download Eclipse IDE for C/C++ Linux Developers (includes Incubating components), (120 MB) with inbuilt LinuxTools like valgrind, gprof, systemtap etc.

Installing/Updating LinuxTools using UpdateManager (Note: You may need to do a Java6 JRE update as described below first.)
Updating Eclipse Helios CDT with UpdateManager

Helios Installation how-to

Java6 JRE update :apt-get install sun-java6-jre

Unzip the Eclipse tarball and run the eclipse binary from inside the tarball:

tar -zxf eclipse-cpp-helios-linux-gtk.tar.gz && ./eclipse

[Website]

[Usage]

[Docs]

[Whitepapers]

[Interview]

Interview with Valgrind Author Julian Seward

[Cpp Check tool integration with Eclipse]

cppcheclipse integration of with Eclipse CDT from (google code):
About: http://code.google.com/a/eclipselabs.org/p/cppcheclipse/
Wiki: http://code.google.com/a/eclipselabs.org/p/cppcheclipse/wiki/Installation
Download: http://code.google.com/a/eclipselabs.org/p/cppcheclipse/downloads/list

Under The Hood Look At Operating Systems Internals with Windows and Linux

2010-08-19T12:39:00.000-07:00

[08-Sep-2010]

Extremely Recommended reading:

Checkout this Blog on Operating Systems (Linux And Windows) by Gustavo Duartes http://duartes.org/gustavo/blog/

This blog has some simply delicious diagrams with 1-2 page explanations of Paging, Virtual Memory, Caching, Physical level RAM, Snapshot of a Process in Memory.
This is a simply superb blog. "A picture is worth a thousand words!!". The articles have some high quality illustrations which esp. for visual learners is a delight. Just working through the flow in the diagrams makes the text just an add-on (to explicitly elaborate on any point you might have missed).
This helps you get an "all-at-once" picture of the entire flow and inter-relationships between different parts (esp. if you're a visual/top-down learner).
I learned more in 30 minutes of analyzing these lovely diagrams than boring holes in all the below books for days on end.

Once you've gone through this blog the below books become so much more intelligible:

Operating System Concepts 5th ed. by Galvin et. al.
Understanding the Linux Kernel 3rd ed. by Bovet and Cesati
Linux System Programming by Robert Love

Good article on RSS and VSZ reporting by ps aux and pmap to determine memory footprint of your proces.
See the comments for some good discussion of internals

Why we need Pointers - An Everyday Analogy using Trains/Telephone Number

2009-12-16T00:22:00.000-08:00

Everyday Analogy

1) We regularly use pointers in everyday life when we use telephone numbers.
2) Another notable use is in chains and trains (concrete examples of linked lists). A chain is a group of things linked together by malleable joints. These joints are easily changeable when adding/removing new links/compartments to the chain.

Note : 
 a)Telephone no.s give 2-way access whereas a pointer gives only 1-way access.
 b)Usually the no. of links is 1 to 3 in an access path.

Tom ---> Jerry
Tom ---> 1 ---> Jerry
Tom ---> 1 ---> 2 ---> .... ---> N ---> Jerry

Here Tom calls Jerry by

a)Getting the contact no. directly or indirectly from 'a friend-of-a-friend-of-a-friend'.
b)Dialling the number.

Here the intermediate links of the chain can change the destination similar to an operator diverting your call to the concerned person in an organisation. Say Tom wants some info (from Jerry), but N on the path knows that Mortimer is a better source of info and gives Mortimer's no. instead.

a)Original path:
Tom ---> 1 ---> 2 --->...N --->Jerry

b)Redirection:
Tom ---> 1 ---> 2 --->...N ---> Mortimer

This is similar to shifting tracks for a train, we can easily divert the train to whatever track by using the shunting mechanism.
----
Note:
I'd contributed this article as a section on the wikipedia page for C/C++ pointers, but some time later it disappeared in the rather over zealous editing by the page maintainers who totally mangled it into bits and threw the ashes to the winds. I had to rescue it from the edit history spending a few hours to track down my original post and now it has a permanent home here. I was really gratified to get one comment from one of the reviewers there (talk section). Really made my day that I'd managed to simply convey the heart of pointers to a non-programmer in terms they could easily identify with, understand and even explain to some one else. Why we need pointers at all in the first place.
Good Pointer Fun with Binky Video from Stanford University.

Tech Talkies

Good Articles on Internals of C++ and Unix

Remotely editing files with ssh, sshmenu, bcvi and vim

Browsing XSLT with Vim by adding a Custom Language to Ctags

XSLT Source Code Browsing with Vim and Ctags

Creating a tags file

Other languages

Apprenticeship Patterns: Patterns and Anti-Patterns of Problem-Solving

How-to Repair an Oracle Database using Putty, SQL Developer GUI and some trial-and-error

Network and SysAdmin, Scripting, Debugging, O.S. Books

Valgrind Cheat-Sheet Notes

Open Source Projects and PeopleWare

Useful Collection of Linux Server Tutorials to Configure Different Services

Valgrind website updation on Eclipse IDE integration via LinuxTools plugin suite

Qualities of a Great Programmer

Linux FileSystems

Howto Speed Up Your Work Using Linux Command Line Tools

Using Multiple User Profiles in FireFox

Howto Setup FireFox4 beta 8 on Linux Fedora Core 14

Networking Protocol, RFC and Administration Links

Study Notes RARP Protocol

Compare features of different wiki software

Network Debug Utilities

STUB: TechTalk: C++ : What happens during compilation?

Linux KVM Kernel Virtual Machine

Reviews of Classic Technical Books

Remote Debugging with GDB

Debugging Multiple Processes/Threads with GDB

The Pyramid of Knowledge

Howto Learn in Small Chunks - (Bite Sized Learning)

Useful Sections of a Syntopic Learning Post

Howto Capture Your Ideas and Knowledge into a MindMap using Freemind

Howto do Reverse Debugging with GDB

[Stub] Debugging Strategies and Techniques

Howto Debug with GDB

Under The Hood Look At Shared and Static Libraries, Linkers and Loaders

Howto Look Inside Executables, Libraries and Object Files

Learning Python - Collection of Resources and Links

MediaPacker - Utility to help pack your DVDs and CDs to the brim

StarUml is dead (NOT)!! Long Live the Stars!!

Delta Debugging

Adv Debugging - My Program Worked Yesterday, but Not Today (WYNOT) by Andreas Zellar

Debugging with GDB's Cheat-Sheet of Commonly Used Options

Howto Debug a Core-Dump/Crash-Dump for a stripped binary from a production machine

Steps towards Technical Mastery

Basic Template with Ingredients for a Technical Blog

Understand Source Code by Reading Code and Refactoring for Maintaining Large Projects

Howto Start a Blog, Get Useful Blogging Ideas, Add Good Content, Reduce Effort with Tools and Keep Blogging

Howto Improve your Blog's design

mmap() is not the territory!! Part 2

Code Review Tools

Push your blog to google for indexing

mmap() is not the territory!! Part 1

Creating a CHM file from offline/mirrored HTML pages

List of useful packages for C/C++ development on Ubuntu Linux Part 2

Howto subscribe to this (and other) RSS Feeds.

Why write technical blog posts Part 2

"Problem:

Solution:

List of useful addons for FireFox (with links) Part 2

DejaClick

FloatNotes

Utils for Linux and Windows

Why write technical blog posts Part 1

The Genius of Jerry Weinberg - The Psyche of Programming

Mindmap of my observations/experiences in "Apprenticeship Patterns Applied"

How to find an answer to (some) of your questions - in Life, the Internet and Other Forums ;-) !!!

List of useful addons for FireFox (with links) Part 1

List of useful packages for C/C++ development on Ubuntu Linux Part 1

Installing Eclipse C++ CDT with Linux Tools for debugging and profiling applications on Linux

Under The Hood Look At Operating Systems Internals with Windows and Linux

Why we need Pointers - An Everyday Analogy using Trains/Telephone Number

Everyday Analogy