After 1.5 years, finally launchpad team has fixed the bug which I had logged into launchpad itself.
Well, I cannot explain the feeling of relief you get, when you see the bug reported by you marked as fixed!
Time for a nice dinner and some sleep.. 
Links:
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; }
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.
sudo apt-get install subversionsvnadmin create ~/my_svn_repo'~/my_svn_repo' cd ~/my_svn_repo/confvi svnserve.conf gedit svnserve.confanon-access = read
auth-access = writeanon-access = none# anonymous users can only read the repository
anon-access = read
# authenticated users can both read and write
auth-access = write# anonymous users aren't allowed
anon-access = none
# authenticated users can both read and write
auth-access = writepassword-db = passwdharry = harryssecret
sally = sallyssecretraghu = mypassword svnserve -d --root ~/my_svn_repo/svn://localhostsvn co svn://localhost my_svn_workssvn mkdir branches tags trunksvn commitecho "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 defaultssudo update-rc.d -f run_svnd remove && sudo rm /etc/init.d/run_svnd
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..
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:
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:
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 wasraghunayak@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.
