The Innovation Lover

Today digg has about “Why do I love Linux” I found it interesting and added the pic here.

The prime reason why use GNU/Linux.

It has been a long time, since the mid of the last year I were writing lots of code fragments in C programming language.

Ever since I started using Input console functions like scanf(), getchar() etc. I faced a common problem most of the times. But I ignored it by several adjustments. Last day I had a good mood for investigating and fixing this problem. Let me describe you the head scratching code.

main()
{
        char a[10],b,c[10];
 
        printf("Enter string1:");
        scanf("%s",a);
 
        printf("Enter char");
        b=getchar();
 
        printf("Enter String2:");
        scanf("%s",c);
 
        printf("\n Read strings: %s  %c  %s",a,b,c);
}

Output :

[slynux@localhost logs]$ ./a.out
Enter string1:string
Enter charEnter String2:who

Read strings: string
T
The expected output is:

[slynux@localhost logs]$ ./a.out
Enter string1:string
Enter char:c
Enter String2:who

 Read strings: string c who 

But it doesn’t happen.
I was having some conversation with vu2swx (Sunil Sir). [ He is one of my Gurus to GNU/Linux]. He told me that this problem happens because, getchar() takes one character from standard input buffer (stdin). From googling a bit I learned that lots of people face the same problem and I couldn’t find some clearcut solution to the problem.

In order to prevent getchar to read a character from input buffer, adding an extra getchar before original getchar will help. The extra getchar reads off the unrequired character and hence expected output is produced. Sometimes clearing buffer may also help. fflush(stdin) can be used.

Modify the code as below:

main()
{
        char a[10],b,c[10];
 
        printf("Enter string1:");
        scanf("%s",a);
        getchar(); // to absorb the char from stdin buffer.
 
        printf("Enter char:");
        b=getchar();
 
        printf("Enter String2:");
        scanf("%s",c);
 
        printf("\n Read strings: %s  %c  %s",a,b,c);
}

During Computer LABs, I used to find lots of guyz struggling with this getchar() related this type of problem. I think this blog post may help my peers.

UPDATE 18.05.2k8 :
Here is the right way to resolve this problem

Considering the comments on this post, I tried out gnu readline library. It solves the problem.

char * readline (const char *prompt);

readline function will return a pointer to a string line and we can pass the text to be prompted. it saves two line code into one line.

example:

 
#include < stdio.h>
#include < readline/readline.h >
 
main()
{
        char *str = readline ("Enter a line of text :");
        printf(str);
}

while compiling do,

$ gcc prg.c -lreadline

It works fine.

Finally, Google Summer of Code application selection list has published.
Gladly, I’m one among the list. This is the fourth edition of google summer of code program which is held annually by google for promoting Open Source Software development. Lots students across the world contribute by writing code during gsoc period. Lots of open source organisations(google shortlisted organisations) project ideas. Students can either choose some idea or they can propose idea of their own and submit project proposals. The organisations will review the applications and they will select eligible students. They will be given 3 months time period for planning and coding.

For more info on gsoc program see FAQ.

I am selected for non-linear editor / Screen cast helper project under Fedora as mentor organisation.
Basically I will be working for updation and addition of some features to an existing Open Source video editor PiTiVi including direct screen cast from GNU/Linux desktop. I came up with the idea of a basic video editor based on ffmpeg platform. ie, I was planning to writing a GUI for ffmpeg which is rich library having only a commandline interface. In GNU/Linux platform, we really miss a simple video editor for carrying out simple tasks such as cutting movie clips, mixing, converting between formats etc. I found similar idea on Fedora community gsoc 2008 project list put forwarded by Kushal Das. Developing an ogg video editor. I was impressed and applied for it. Finally, John Palmieri came up offering me mentoring if I could do updation and making PiTiVi much usable by adding some features. I was impressed by looking at PiTiVi and applied for the project.

Today the news is up. ” Congratulations !, I am selected for gsoc 2008

http://code.google.com/soc/2008/fedora/about.html

I would like to thank Santhosh Thottingal, for urging me to apply for gsoc 2008.

The challenge:
I have to work on PyGTK with a combination of gstreamer python bindings and gnonlin. Even though these libs would be much more interesting to work. I dont think it isn’t easier. I haven’t probed my hands much into these libs for hacks till now. Its going to be the first attempt anyway. Anyway the target is a challenge limited in 3 months time. Its a fun in doing everything with FOSS !

Latest: University exams are scheduled for June :D. Since I’m gonna play with gsoc project, GOD truly knows what I’m going to write for exams.

Cheers!
Have fun.

UPDATE: I have successfully completed the work with PiTiVi Read follow ups here.