OpenGuru.org

Dark Knight - My Qt Creator Dark Color scheme

2010-02-17T22:50:00.001+05:30

Here is my own Dark color scheme for Qt Creator. I have named it as Dark Knight.

See the screenshot below.

To use this color scheme, download this XML file and follow following steps.

How to install:

Goto the Qt Creator setting directory, which is
Documents and Settings\ <user name> \Application Data\Nokia\qtcreator under Microsoft Windows XP (replace <user name> with your login name)

and
~/.config/Nokia\qtcreator under Linux.
Goto the directory named styles.
Place the downloaded XML file in this directory.

How to change the color scheme in Qt Creator:

Goto Fonts & Colors settings.
(To open, go through Tools->Options->Text Editor->Font & Colors)
Scroll down and select the new color scheme named Dark Knight.
Press OK.
Enjoy.

Note: As Qt Creator is in active development, above mentioned steps may not work with future version of Qt Creator.

I hope you people like it. Suggestions & comments are welcome.

Technorati tags: OpenGuru.org weblog, Qt Creator, Dark Color Scheme.

How To: Compile MICO-CORBA in SUN Solaris

2010-02-12T12:05:00.039+05:30

Here are the steps to download, build and install the MICO COBRA under SUN Solaris machine.

Download MICO CORBA.
Open the terminal window in the directory where you kept the downloaded archive file.
Extract the content of the downloaded archive.
gzip -dc mico-*.tar.gz | tar -xf –
And if you are using GNU tar utility (if not installed already, get it from SUN Freeware website.) then
tar -zxvf mico-*.tar.gz

Run the configure script.

You can set many parameters through the command line arguments to the configure script. Such parameters are, install directory, Qt directory etc. Check INSTALL.txt file for more information on the list of command line arguments.

Here are my arguments to the configure script
./configure --with-qt=/sect/package/qt/ --prefix=/sect/package/mico-corba/
Here I have enabled the support for Qt (which is installed in =/sect/package/qt/ directory) and I have indicated that I am planning to install MICO into /sect/package/mico-corba directory.

Read INSTALL.txt for more information on this.

Note: When I used one of configure script argument named --enable-final switch, I ended with compilation errors under Solaris. If you are also getting compilation errors, Check if you have used this switch. As per document this switch won’t work under HP-UX. I guess this is applicable to all Unices.

Run the make tool.
Issue make command for this.
make
or if you have GNU make installed (or install it from SUN Freeware website)
gmake

Install the MICO CORBA
Issue the following command in terminal to install MICO to configured directory(if any set while configure script) or to the default directory.
make install
or
gmake install

Update the environmental variables to include MICO install directory.
Before you can compile, link and execute your first CORBA application, you need to setup the environmental variables correctly.

Add /sect/package/mico-corba to your PATH environment variable.
In Bash
PATH=$pATH:/sect/pckage/mico-corba/bin
And in csh
setenv PATH /sect/package/mico-corba/bin:$PATH

Also modify LD_LIBRARY_PATH to properly link with MICO libraries.
LD_LIBRARY_PATH=$LD_LIBRARY_PAT:/sect/package/mico-corba/lib

If required modify the Bash Profile file to set these environment variable at start-up.

Or you can run Solaris crle command once and add MICO lib directory in it.(Recommended method)

crle -u -l /sect/package/mico-corba/lib

That's all.

Please leave a comment if this post was useful to you!

Qt: The best way to set the Application version

2009-11-28T16:21:00.029+05:30

Whenever we develop any application one of the basic stuff which we need to decide is the application version number. Historically the application version number format is one of the hot topics where many lengthy wars/debates have happened.

This post is NOT about the application version number format to use, instead in this post I would be concentrating how to set and use the application version number information in a Qt project.

If this post is on any use to you, please leave a comment.

First way: Defining the version information within the application source code

The application version can be set as through the string constant or preprocessor Macro defined in some header file.

I have used this method many times before.

Also, here once you create the QApplication object, you can set this application version to QApplication object and ignore this constant/Macro defined from then on. Whenever you need the application version you can directly get it from qApp global QApplication object.

You can use following APIs

QString applicationVersion()
void setApplicationVersion(const QString & version)

Second way: Defining the version information within the Qt project file.

You can use Qt QMake Macro named VERSION to define the Application version.

Eg:



VERSION = 1.0

The good thing with this QMake Macro is that, it automatically creates the .rc file under Microsoft Windows and you can see the application version number from Windows Explorer by right clicking on the executable.

Eg:

What I do is that, I use preprocessor Macro defined through Qt project file to pass application version number to code.

Eg:



# The application version

VERSION = 1.0



# Define the preprocessor macro to get the application version in our application.

DEFINES += APP_VERSION=\\\"$$VERSION\\\"

Note: \\\" is important! Without them, the Macro is taken as a double constant instead of string constant.

Now use the Macro APP_VERSION in your code just like any other preprocessor Macro.

Eg:

    QApplication app(argc, argv);

    // Setting the Application version
    app.setApplicationVersion(APP_VERSION);

Similarly you can set the Application date also.

You can browse the sample Qt project @ My Google code page.

Technorati tags: OpenGuru.org weblog, Qt, Application version.

C++ Gyan of the day: Friend class and Inheritance

2009-10-28T23:24:00.002+05:30

Check if the following code snippet is proper.

/*
 * Copyright (C) 2009 Raghavendra Nayak
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

// Program to explain the Friend class and inheritance

#include <iostream>
#include <cstdlib>

////////////////////////////////////////////////////////////////////////////////

class someClass {
public:
    void printData() {
        std::cout<<"The value of m_data is "<<m_data;
    }
private:
    int m_data;

    // declare BaseClass as the friend class to this class
    friend class BaseClass;
};

////////////////////////////////////////////////////////////////////////////////

class BaseClass {
public:
    /// @brief The BaseClass constructor.
    BaseClass() {
        std::cout<<"In BaseClass constructor.\n"
                 <<"Setting the m_data to 10.\n";
        // set m_data to 10
        m_someClassObject.m_data = 10;
        // print the set value using printData method.
        m_someClassObject.printData();
    }
protected:
    someClass m_someClassObject;
};

////////////////////////////////////////////////////////////////////////////////

class DerivedClass : public BaseClass {
public:
    /// @brief The DerivedClass constructor.
    DerivedClass() {
        std::cout<<"In DerivedClass constructor.\n"
                 <<"Setting the m_data to 20.\n";
        // set m_data to 20
        m_someClassObject.m_data = 20;
        // print the set value using printData method.
        m_someClassObject.printData();
    }
};

int main(int /*argc*/, char */*argv*/[])
{
    DerivedClass derivedClassObject;

    return EXIT_SUCCESS;
}

If you try to compile this, you will end up with compilation errors. the reason is in the comments.

Technorati tags: OpenGuru.org weblog.

A big sigh of relief

2009-06-18T22:21:00.001+05:30

After 1.5 years, finally launchpad team has fixed the bug with launchpad which I had filed in launchpad itself.

Well, I cannot explain the feeling of relief you get, when you finally see the bug reported by you being marked as fixed!!

Time for a nice dinner and some sleep..

Links:

Launchpad Bug report

C Language: Program to check given character string for palindrome

2009-05-12T23:17:00.002+05:30

A palindrome is a word, phrase, number or other sequence of units that can be read the same way in either direction. Eg: Katak, 121 etc

Following C program shows the simple way check, if the given character string is a palindrome or not.

Following code is available under GNU General Public License v3 or above.

/*
 * Copyright (c) 2009 Raghavendra Nayak
 *
 * Permission is hereby granted, free of charge, to any person obtaining a copy
 * of this software and associated documentation files (the "Software"), to deal
 * in the Software without restriction, including without limitation the rights
 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 * copies of the Software, and to permit persons to whom the Software is
 * furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
 * THE SOFTWARE.
 */

/*
 * C program to reverse given string, and to check whether it is a palindrome.
 */

#include <stdio.h>
#include <string.h>

/**
 * @brief function to return the given string length.
 * @param[in] string the input string.
 * @return the string length.
 */
unsigned int get_string_length(const char *string)
{
    int i;
    int string_length = 0;

    for (i = 0; string[i] != 0 && string[i] != '\n'; ++i)
        ++string_length;
    return string_length;
}

/**
 * @brief function to reverse the given string.
 * @param[in] string the input string.
 * @param[out] rev_string the reversed string would be placed in this variable.
 * @return none.
 */
void reverse(const char *in_string, char *rev_string)
{
    int i, j;
    unsigned int length;

    length = get_string_length(in_string);

    for (i = length-1, j = 0; i >= 0; --i, ++j)
        rev_string[j] = in_string[i];

    /* mark the end of string */
    rev_string[j] = 0;
}

int main()
{
    const int max_size = 100;
    int string_length = 0;

    char string[max_size];
    char reverse_string[max_size];

    printf("\nPlease enter input string: ");
    /* Note: we are not using gets, because gets is deprecated and can be
       dangerous. */
    fgets(string, max_size, stdin);

    /* remove any new line from input string,
       if fgets has put '\n' at the end of string */
    string_length = get_string_length(string);
    string[string_length] = 0;

    /* get the reversed string */
    reverse(string, reverse_string);

    /* now compare */
    if (!strcmp(string, reverse_string)) {
        printf("\nEntered string = %s, reversed string = %s."
               "\n%s = %s, hence %s is a palindrome.\n",
               string, reverse_string, string, reverse_string, string);
    } else {
        printf("\nEntered string = %s, reversed string = %s."
               "\n%s != %s, hence %s is not a palindrome.\n",
               string, reverse_string, string, reverse_string, string);
    }
    return 0;
}

Links:

How To: Create your own local SVN repository in GNU/Linux

2009-04-19T16:16:00.000+05:30

This article tell you about creating your own local SVN repository in your GNU/Linux box.

Even though I personally like git, I like the SVN's idea of having all your code safe somewhere in a remote server!

I personally do a lot of coding, and several times I have lost my precious programs/codes due to some stupid mistakes I did or because I don't backup my code very often. Keeping a plain backup your code is a pain, having you to maintain several copies of them, based on their version.

Hence, several times I felt that, oh God, if at all I had my own SVN server somewhere?

So, today finally tried to create my own SVN server, and voila, in less than 5 minutes, my own SVN server was up and running! I never had thought that creating your own SVN server was a such easy task.

If you people are looking for the same, this article is for you!

Here is a step by step procedure to create your own SVN server.

Install SVN package.

You need to have subversion package installed.

If you don't have it, install it using command

sudo apt-get install subversion
Create a SVN repository.

Next step is to create a SVN repository. First decide where you want to store your repository data? I kept my SVN repository in my home directory, so that it also gets backed up with my home directory backup. So, You can also do the same or store your SVN repository in any other place of your choice.

Use following command to create your own SVN repository in your home directory.

svnadmin create ~/my_svn_repo
This command will create a directory named 'my_svn_repo in' your home directory, with SVN's repository data inside it.

If you want to store your SVN repository somewhere else, replace

'~/my_svn_repo'
with your selected directory path.
Change the SVN configuration for repository access.

You need to configure the SVN to tell it about the read and write access to your repository.

For this goto 'conf' directory present inside your SVN repository directory.

cd ~/my_svn_repo/conf
now open the file named svnserve.conf

vi svnserve.conf
OR

gedit svnserve.conf
and edit the file.

un-comment following lines (remove # from the beginning of the line.)

anon-access = read auth-access = write
These lines tell about the read and write access to your SVN repository. 'anon-access = read' means anonymous users can read your SVN data.

The possible values are 'read', 'write' and 'none'. The default value 'read' should be OK, as its a local repository. However, if your machine is in a network, you may want to change it to 'none' . ie;

anon-access = none
The second line 'auth-access = write' tells about the access rights of the authorized users. The default value of 'write' should be OK and it means authorized users can read/write back the data to the SVN repository.

Below are some possible configurations;
- The default configuration
  
  # anonymous users can only read the repository anon-access = read # authenticated users can both read and write auth-access = write
- Restricted configuration
  
  # anonymous users aren't allowed anon-access = none # authenticated users can both read and write auth-access = write
Configure the Authorization.

un-comment following lines from the 'svnserve.conf' file opened in previous step.

password-db = passwd
This tells the SVN to read the user name and password from the file named 'passwd'.
Setup the username and password.

Open the file name 'passwd' present inside 'conf' directory of your SVN repository directory.

Now un-comment the following lines.

harry = harryssecret sally = sallyssecret
This line tells the authorized user's name ans password. You can also add your username and password to this list. like

raghu = mypassword
or use existing username and password such as 'sally' and ~~'billy'~~, oops.. 'harry'.
Start the daemon process.

Now enter following command to start the SVN daemon process.

svnserve -d --root ~/my_svn_repo/

that's it. you can now checkout your own local SVN repository like any other SVN repository. Just use following URL to access your local SVN repository.

svn://localhost
example:

svn co svn://localhost my_svn_works
Creating SVN directory structure:(optional)

Like the SVN's general convention, I recommend you to create 3 different directories. They are trunk, tags and branches.

use following command to create them

svn mkdir branches tags trunk
now commit them to SVN.

svn commit
Making your SVN daemon process to start automatically with system.

The steps given above will start the daemon process, however if you restart your system, again you need to manually start the daemon process. Otherwise you can add a script to start the daemon process automatically with your system.

For this, You need to add a script to your /etc/init.d/

use following command to do it

echo "svnserve -d --root /home/raghunayak/my_svn_repo/" >> run_svnd && chmod +x run_svnd && sudo mv run_svnd /etc/init.d && sudo update-rc.d run_svnd defaults

In this command replace '/home/raghunayak/my_svn_repo' with with your SVN repository path.

To remove this startup script enter following command.

sudo update-rc.d -f run_svnd remove && sudo rm /etc/init.d/run_svnd
If you like this article, please leave a comment..

New Category - Tech Recipe

2009-04-19T13:29:00.001+05:30

I have just created a new post category named Tech Recipes. From today on wards I would be posting some new articles under this category.

In this category I would be asking some technical questions to you people, with the answer. The questions are most likely to be programming language related, with some exceptions. I hope these questionnaire would be very useful to the people, who are preparing for interviews or just want to improve their hold in programming languages.

So, Keep watching this space for more on this..

Technorati : Tech Recipe Questionnaire

Del.icio.us : Tech Recipe, Questionnaire

Zooomr : Tech Recipe, Questionnaire

Flickr : Tech Recipe, Questionnaire

New License

2009-04-15T01:13:00.000+05:30

I have changed the license used for sample codes. Most of the new sample codes are now released under more permissive MIT license, rather than copyleft GNU license.

I hope this change would help many people.

- Raghu Nayak

Update:
I have again changed the code license. I have re-licensed all my programs/source code under GNU General Public License version 3 or above (at your option).

Reasons or motivations behind this change:

Freedoms of the user:
I actually spend a lot of effort while coding or programming, and I really want my effort to be useful to someone! At the same time, I really don't want someone to take my code and convert it into a proprietary trap, thereby killing all user freedoms. I really want to protect the basic rights or the freedoms of the user, and this can be ensured only with GNU GPL.
The recent acquisition of SUN Microsystem by Oracle had a strong influence on my decision. I really Thank GOD that, MySQL code is available under GNU GPL. So, even if Oracle kills it, somebody will fork it.
This article, which I saw in GNU website.

So, I am sorry to all those who wanted to integrate use my code with their proprietary code. I am sorry, but this action was necessary to protect the basic freedom, on which I have strong belief.

- Raghu Nayak

CMake: Detecting Platform/Operating Systems, Compiler Information

2009-04-13T00:06:00.000+05:30

I was searching for this information from last three days. Finally I found the CMake syntax to write the platform specific code inside CMakeLists.txt.

Detecting the Operating System:

CMake actually defines several variables to identify the platform information. These variables will be assigned with the values based on the platform, operating system etc.

For example, In CMake version 2.6 following Variables are present to identify the Operating System Type.

UNIX
     is TRUE on all UNIX-like OS's, including Apple OS X and CygWin
WIN32
     is TRUE on Windows, including CygWin
APPLE
     is TRUE on Apple systems. Note: Having this variable value set to TRUE does not necessarily mean that Operating System is Mac OS X. It only means that in the C/C++ header file __APPLE__ Macro is defined. Use the alternate method of detecting Operating System type, mentioned below instead.

For GNU/Linux: There is NO Variable for GNU/Linux. ie; IF(LINUX) does NOT work. Use the alternative method mentioned below instead.

Alternative method to detect to Operating System:

CMake version 2.6 defines 2 different variables, which can be used to detect the Operating System preciously. They are,

CMAKE_SYSTEM
     the complete system name, e.g. "Linux-2.4.22", "FreeBSD-5.4-RELEASE" or "Windows 5.1"
CMAKE_SYSTEM_NAME
     the short system name, e.g. "Linux", "FreeBSD" or "Windows"

These variables can be used to detect the Operating System.

Example:

IF(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")

# Mac OS X specific code

     SET(OperatingSystem "Mac OS X")

ENDIF(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")

for detecting Mac OS X

and for Linux

IF(${CMAKE_SYSTEM_NAME} MATCHES "Linux")

# Linux specific code

     SET(OperatingSystem "Linux")

ENDIF(${CMAKE_SYSTEM_NAME} MATCHES "Linux")

Detecting the compiler:

Following variables can be used to detect the compilers.

MINGW
     is TRUE when using the MinGW compiler in Windows
MSYS
     is TRUE when using the MSYS developer environment in Windows
BORLAND
     is TRUE on Windows when using a Borland compiler
WATCOM
     is TRUE on Windows when using the Open Watcom compiler
MSVC, MSVC_IDE, MSVC60, MSVC70, MSVC71, MSVC80, CMAKE_COMPILER_2005, MSVC90
     Microsoft compiler
CMAKE_COMPILER_IS_GNUCC
     is TRUE if the compiler is a variant of gcc
CMAKE_COMPILER_IS_GNUCXX
     is TRUE if the compiler is a variant of g++
CYGWIN
     is TRUE on Windows when using the CygWin version of cmake

Detecting the System Processor:

Following variable can be used to detect the processor family.

CMAKE_SYSTEM_PROCESSOR
     the processor name (e.g. "Intel(R) Pentium(R) M processor 2.00GHz")

Example usage:

IF(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")

     # Mac OS X specific code

     SET(OperatingSystem "Mac OS X")



     IF(${CMAKE_SYSTEM_PROCESSOR } MATCHES "Intel")

         # Intel Mac OS X specific code

         SET(Processor "Intel")

     ENDIF(${CMAKE_SYSTEM_PROCESSOR } MATCHES "Intel")



ENDIF(${CMAKE_SYSTEM_NAME} MATCHES "Darwin")

Links:

CMake wiki

How To: Fix shared library load problem in GNU/Linux

2009-04-12T13:38:00.000+05:30

I recently started learning/using Google C++ Testing framework.

I compiled and installed Google testing framework as per the instruction. But still I wasn't able to run the sample applications compiled by me.

Whenever I run them, I used to get following error.

error while loading shared libraries: libgtest.so.0: cannot open shared object file: No such file or directory

But I had installed Google test framework properly. The install script had properly placed the libgtest.so.0 into /usr/local/lib

So, to check which all shared library are failed to load, I issued following command

$ ldd a.out

and the output was

raghunayak@raghu-desktop:~/google_test/samples$ ldd a.out
        libgtest.so.0 => not found
        libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x00002b2897d75000)
        libm.so.6 => /lib/libm.so.6 (0x00002b2898080000)
        libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x00002b2898301000)
        libc.so.6 => /lib/libc.so.6 (0x00002b2898510000)
        /lib64/ld-linux-x86-64.so.2 (0x00002b2897b57000)

Which showed that, only libraries placed in /usr/local/lib are failed to load. This gave me a hint that, /usr/local/lib is not the ld library search path.

To confirm this, I entered following command, which lists all the libraries that ld can load.

$ ldconfig -p

This confirmed that, /usr/local/lib is indeed missing from ld library search path.

So, to include /usr/local/lib into the ld library search path, I typed following into the terminal.

$ LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib/

after this, I typed

$ ldd a.out

and this time the ld was able to properly find the library gtest.so.0 placed in '/usr/local/lib'

raghunayak@raghu-desktop:~/google_test/samples$ ldd a.out
        libgtest.so.0 => /usr/local/lib/libgtest.so.0 (0x00002ae54f520000)
        libstdc++.so.6 => /usr/lib/libstdc++.so.6 (0x00002ae54f772000)
        libm.so.6 => /lib/libm.so.6 (0x00002ae54fa7d000)
        libgcc_s.so.1 => /lib/libgcc_s.so.1 (0x00002ae54fcfe000)
        libc.so.6 => /lib/libc.so.6 (0x00002ae54ff0d000)
        /lib64/ld-linux-x86-64.so.2 (0x00002ae54f302000)

After this I was able to run samples without any problems.

Temporary Solution:

Temporary solution is to add '/usr/local/lib' into the environmental variable named LD_LIBRARY_PATH

so, the solution is to add /usr/local/lib into the enviornment variable named LD_LIBRARY_PATH, by typing

You can do this by typing

$ LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib/

Permanent solution:

permanent solution is to modify the file /etc/ld.so.conf and add the path /usr/local/lib into it.

You can do it manually by typing

$ sudo gedit /etc/ld.so.conf

or type following into the terminal

$ sudo bash -c 'echo /usr/local/lib >> /etc/ld.so.conf ' && sudo ldconfig

P.S.: I think GNU/Linux distributions by default should include /usr/local/lib in /etc/ld.so.conf or at-least the install script of the libraries should have this intelligence.

C Language: Program to find if a given number is prime

2009-04-11T10:46:00.000+05:30

Following sample program shows how to find, if the given input number is prime or not.

This code is released under the terms of GNU General Public License.

/*
 * Copyright (C) 2009 Raghavendra Nayak
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <stdlib.h>

/**
 * @brief function to check if the given number is prime.
 *
 * This function returns 1 if the given number is a prime number,
 * otherwise returns 0.
 *
 * @param[in] number    input number to check for prime number.
 * @return  1: if the @sa number is a prime number;
 *          0: otherwise.
 *
 * Note: This function uses a loop to find the factorial.
 */
unsigned short is_prime_number(const int number)
{
    int i;

    /* Trivial case 1: number 1, 0 numbers are not prime numbers */
    /* -ve numbers are not natural numbers */
    if (number <= 1)
        return 0;

    /* Trivial case 2: even numbers are not prime numbers */
    if (number % 2 == 0)
        return (number == 2) ? 1 : 0;

    /* here, number is is odd and number >= 3 */
    /* Try to divide number by every odd number i, starting from 3 */
    for (i = 3; ; i += 2) {
        /* We only have to try i up to the squre root of number */
        if (i > number/i)
            break;

        /* Now, we have i <= number/i < number */
        /* If number is divisible by i, number is not prime */
        if (number % i == 0)
            return 0;
    }
    /* number has no integer factor in the range (1, number), and thus is prime */
    return 1;
}

int main(void)
{
    int number;
    unsigned short prime_number;

    printf("\nEnter the input number: ");
    scanf("%d", &number);

    prime_number = is_prime_number(number);

    if (prime_number) {
        printf("\nInput number %d is a prime number.\n", number);
    } else {
        printf("\nInput number %d is not a prime number.\n", number);
    }
    return EXIT_SUCCESS;
}

To download the project click here. or you can visit Google code project at http://code.google.com/p/nayak.

Building the project:

You can build this project using any of the following method.

$ gcc is_prime_number.c -o is_prime_number
$ make
$ cmake . && make

First method requires you to have gcc installed.
Second method requires you to have gcc along with the GNU make installed.
Third method requires you to have cmake along with GNU make.

To execute the compiled binary issue following command.

$ ./is_prime_number

C Language: finding factorial of a number using looping

2009-04-11T09:47:00.001+05:30

Following sample program shows how to find the factorial of a number using looping.

This code is released under the terms of GNU General Public License.

/*
 * Copyright (C) 2009 Raghavendra Nayak
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <stdio.h>
#include <stdlib.h>

/**
* @brief function to find the factorial of a number.
*
* This function returns number! (the factorial of number).
* For negative number, number! is defined to be 1.
*
* @param[in] number    the number for which you want to find the factorial.
* @return  The factorial of the @sa number.
*
* Note: This function uses a loop to find the factorial.
*/
int factorial(const int number)
{
int result = 1;
int i;
for (i = 1; i <= number; i++) {
result *= i;
}
return result;
}

int main(void)
{
int number;
int factorial_of_number;

printf("\nEnter the input number: ");

scanf("%d", &number);

factorial_of_number = factorial(number);

printf("\nInput number is: %d", number);
printf("\nFactorial of %d or %d! is %d\n", number, number, factorial_of_number);

return EXIT_SUCCESS;
}

To download the project click here. or you can visit Google code project at http://code.google.com/p/nayak.

Building the project:

You can build this project using any of the following method.

$ gcc factorial.c -o factorial
$ make
$ cmake . && make

2009-04-08T23:53:00.001+05:30

Currently working on command line parsing utility for my project. This is released under Apache v2 license.

Mac OS X - Show hidden files in Finder

2009-03-14T16:28:00.001+05:30

I have created a simple application, which can be used to show/hide the hidden files in Mac OS X - Finder.

Requirements:

I have tested this application in Mac OS X - Leopard but it should work with Mac OS X - Tiger also.

Usage:

Just launch the application named "Show Hidden Files in Finder"

Download Links:

To download this Application click here.
Download the source code of this application from here.
Download both source code and the Application from here.

Source code released under the terms of GNU GPLv3 or above.

Enjoy..

Apple, Applications, Development, Experiments, Free Softwares, FSF, Hacks, Mac, OpenSource

Qt Creator: My New IDE

2009-03-10T23:48:00.001+05:30

Oh man..

From the day Nokia has released their light weight IDE named Qt Creator, I am just mad about it!

Its awesome.. Its very fast.. Its very lightweight.. It just works!

Actually I don't have words to explain my happiness..

This is the IDE for which I was waiting for, since age..

Qt Creator rocks!!!

P.S.: FYI, Qt Creator has just replaced Komodo Edit as my default code editor.

My new project: iDoubt

2009-03-10T23:12:00.001+05:30

Hi All,

I am pleased announce about my new open source project named iDoubt.

I know the project name would sound like lame to you. Still trust me, the application itself is kind of cool.

More information about the project is coming soon..

I am back!

2009-03-09T16:08:00.000+05:30

I am back after a very long break. (5 months break, to be precise!)

Actually, around 7 months back I switched my company. This switch made me so busy that, I had no time at-all for this blog. So, this switch was the major reason behind my long break.

Anyways, After this switch, now I have even more experiences and experiments to share with you people..

Now expect even more from me.. (Only if I don't take such a long break again, which I won't due to this bloody economic recession.)

C++ - Why constructor method can not be virtual

2008-10-26T16:27:00.000+05:30

In my previous post I explained the need of an virtual destructor. Today let me explain why the constructor method can not be virtual.

For this first let me explain what is a constructor method and what is the use of constructor method.

Constructor Method: Constructor is a method which is used to construct an object and/or optionally initialize its data members.

So, main use of constructor method is to construct and return the object of the class which we intend to construct.

Virtual Method: The virtual method/function is used for run time polymorphism. With the virtual method, the actual method which will be called is decided at the run time depending based upon the type of the object which is used to call the method.

Now if the constructor method was an virtual method, then the constructor which is going to be called would be decided at the run time. ie; the object which you may construct may not be the object of the class whose object you intended to create!

This is why constructor method can not be virtual.

C++ Sample Code - 01

2008-07-06T22:17:00.001+05:30

C++ Sample Code - 01
Skill Level: Intermediate

This sample explains the need of the virtual functions. Scroll down for the download links.

//============================================================================
// Name        : Sample-01.cpp
// Author      : Raghavendra Nayak
// Version     :
// Date        : 07-June-2008
// Copyright   : (c) 2008, Raghavendra Nayak. All rights reserved.
// Description : Sample C++ program. This sample explains the need of
//                 virtual functions.
//============================================================================

/*
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 * Case: 01
 * Please note that, in this program by default we don't use virtual functions,
 * due to which always base class functions are called!
 *
 * To change this behavior define the value of the macro USE_VIRTUAL_FUNC as 1.
 * This will add "virtual" to the base class function prototype.
 *
 * ie; virtual void setData(int inData);
 *
 * After this, you will notice that, proper functions are called..
 *
 * Case: 02
 * Also, note that, virtual functions are hierarchical, ie, if the very first base
 * class is virtual, all the subsequent derived classes will automatically get that
 * property.
 *
 * ie, In this example, myClassC inherits from myClassB and if you
 * define USE_VIRTUAL_FUNC as 1 . This will add virtual keyword to the functions
 * of myClassA (Base class).
 *
 * After this, when you call setData/getData functions, you will see that proper
 * functions are called!
 */

/*
 * Conclusions:
 *
 * 01. If you don' use virtual functions, always base call functions are called.
 * (When called through base class pointer/reference).
 *
 * 02. virtual functions are hierarchical, if the base class has virtual property,
 * all the derived classes automatically get that property..
 */

#include <iostream>

/*
 * Define the value of this macro to 1 to use virtual functions
 */
#define USE_VIRTUAL_FUNC        0

class myClassA {
protected:

        int myData;
public:
#if USE_VIRTUAL_FUNC
        virtual
#endif //USE_VIRTUAL_FUNC
        void setData(int inData)
        {

                std::cout<<"\nWe are in myClassA setData";
                myData = inData;
        }
#if USE_VIRTUAL_FUNC
        virtual
#endif //USE_VIRTUAL_FUNC
        int getData()
        {
                std::cout<<"\nWe are in myClassA getData";

                return myData;
        }
};

class myClassB : public myClassA {

public:
        void setData(int inData)
        {
                std::cout<<"\nWe are in myClassB setData";

                myData = inData;
        }
        
        int getData()
        {
                std::cout<<"\nWe are in myClassB getData";

                return myData;
        }
};

class myClassC : public myClassA {

public:
        void setData(int inData)
        {
                std::cout<<"\nWe are in myClassC setData";

                myData = inData;
        }
        
        int getData()
        {
                std::cout<<"\nWe are in myClassC getData";

                return myData;
        }
};

int main (int argc, char * const argv[])
{

        int option = 1;
        
        std::cout<<"\nWhich case you want to run ? [1/2] : ";

        std::cin>>option;
        
        myClassA *myObjPointer;
        
        if (option == 1)

                myObjPointer = new myClassB; // Case: 01
        else
                myObjPointer = new myClassC; // Case: 02

        
        myObjPointer->setData(10);
        myObjPointer->getData();
        
        return 0;
}

Downloads Links:

Thank You..

2008-07-06T19:27:00.001+05:30

Here is the list of few websites/projects, which has helped me in many ways. This is just a small way to say "Thank You" to them.

Projects:

TestDisk, Data Recovery

Using Mac OS X frameworks with eclipse IDE

2008-07-03T12:20:00.001+05:30

If you are a Mac OS X programmer, you must be aware of frameworks.

If you are like me, who like to use Eclipse than XCode, You can link your programs to the proper frameworks by following steps..

Skill Level: Intermediate

step 01: Open your Eclipse project.
step 02: Right click on your project, select the "properties".
step 03: Now go to "C/C++ Build"->"Setting".
step 04: Go to the "Tool Settings" tab.
step 05: Select the "Miscellaneous" settings, under "Mac OS X C++ Linker".
step 06: You will see a text box with title "Linker Flags"

Check the following screenshot..

Step 07: Enter your framework names here.. Precede your framework name with “-framework” flag.

Eg: If you want to link with Carbon framework, then enter it as -framework carbon

If you want to link with more than one framework add them in the same line using space to separate them..
Eg: -framework carbon -framework opengl
Step 08: Click on Apply to apply the new build settings..

If you like this post, please leave a comment..

Technorati Tags: Mac OS X, How To, Programming Tips, Eclipse C++, Frameworks

New License

2008-06-21T22:29:00.001+05:30

Well, I have been searching for a software license that fits well into my requirement, and I think that, finally I've found one!

It's the new GNU GPL v3 license.

From now onwards, all the samples/projects found in this website will be released under GNU-GPLv3 or above license.

You people are free to contribute your samples/codes to this website, provided that you use a compatible license. Which you can get by adding "or later" clause to GPL license.

Here is the document, which helped me in selecting GPLv3 over the GPLv2.

Technorati Tags: License, GPL v3, GPLv2 vs GPLv3

New contents are coming soon..

2008-05-24T12:45:00.001+05:30

Soon I will write and explain OpenGL, C/C++ and other stuffs here..

Stay tuned..

Technorati Tags: C++, OpenGL, Sample Code

How to Change MyCompanyName of XCode, once and for all

2008-05-24T12:32:00.001+05:30

If you're sick of getting __MyCompanyName__ automatically in copyright notice of all your XCode source files, You can set the XCode default company name for copyright notice as follows..

This is damn simple..

Go to /Applications/Utilities and open Terminal.app and enter the following code there..


defaults write com.apple.Xcode PBXCustomTemplateMacroDefinitions '{ "ORGANIZATIONNAME" = "put_your_company_name_here";}'

For eg:

Here is the line which I entered..

defaults write com.apple.Xcode PBXCustomTemplateMacroDefinitions '{ "ORGANIZATIONNAME" = "Raghavendra Nayak";}'

I have tried this with XCode 3.0 but this should work with older version of XCode as well..

If you want to do the same thing, other way around, check this page at Apple mailing list.

Technorati Tags: Apple XCode, __MyCompanyName__, How To

OpenGuru.org

Dark Knight - My Qt Creator Dark Color scheme

How To: Compile MICO-CORBA in SUN Solaris

Qt: The best way to set the Application version

C++ Gyan of the day: Friend class and Inheritance

A big sigh of relief

C Language: Program to check given character string for palindrome

How To: Create your own local SVN repository in GNU/Linux

New Category - Tech Recipe

New License

CMake: Detecting Platform/Operating Systems, Compiler Information

How To: Fix shared library load problem in GNU/Linux

C Language: Program to find if a given number is prime

C Language: finding factorial of a number using looping

Mac OS X - Show hidden files in Finder

Qt Creator: My New IDE

My new project: iDoubt

I am back!

C++ - Why constructor method can not be virtual

C++ Sample Code - 01

Thank You..

Using Mac OS X frameworks with eclipse IDE

New License

New contents are coming soon..

How to Change __MyCompanyName__ of XCode, once and for all

How to Change MyCompanyName of XCode, once and for all