Implement Timeout for one function in C

saurabh    c, sample programme, Tips    

Here i have one function which is listen mode. this function listing something which i got form some device.

Here when my function is in listen mode that time i want to create timeout. if i will not get any response from particular device than i want o exit from this function and have to notify.

if during this timeout period if i will get some date from something or some action would be performed than i have to continue with work and stop this timeout.
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Why variables can not be declared in a switch statement just after labels?

JIGAR PATEL    c, c++, sample programme, sample programme     switch statement

see this code

#include<stdio.h>
int main()
{
   int i=1;
   switch(i)
   {
       case 1: int x=10;
               printf(" x is %d",x);
       break;
    }
    return 0;
}

Do you think this code will compile? if yes then you need to read this post….

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How can i detect Windows or Linux in C,C++ programming?

JIGAR PATEL    c, c++, linux, sample programme, sample programme, tips    

Sometimes we need to write platform independent  code which works in windows and linux machine without giving any flag or any modification in code or make file manually.

So in such case i usually use compiler generated macro to check the platform .

In Linux all c and c++ compiler define macro like  linux, In Windows all c and c++ compiler define macro like _WIN32 

so we can use this macro to separate code for linux and windows see belows example code

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How can I get what my main function has returned in Linux?

JIGAR PATEL    c, linux, sample programme, tips    

In a C program if we want to give some input from terminal then we can give it by:

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

In the same way, if we want to get return value of main() function then how can we get it?

In each main() we write return 1 or return 0; how can we know what my main() has returned at terminal?

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Equivalent to getch() & getche() in Linux

JIGAR PATEL    c, linux, sample programme, tips     getch() and getche() in linux

Once in one situation i need to use getch() and getche() function in Linux based application so i have searched a lot for Equivalent header file for conio.h in Linux,But i came to know there is not any header file/library equivalent to conio.h in linux.

I want to make a switch case base menu where the user will give his option just by pressing one key & process should be moved ahead. I don’t want to let user to press ENTER after pressing his choice.

Somebody has suggest me very magical code for getch() and getche() function for linux which is i am sharing here. read more

How post-increment & pre-increment both are evaluated in function argument?

saurabh    c, sample programme, Tips     Undefined behaviour in c

#include<stdio.h>
   int main() {
   int a=5;
   printf("%d %d %d",a++,a++,++a);
   return 0;
   } 

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Concept of Octal literal in C

JIGAR PATEL    c, sample programme, Tips     c, Octal literal

One day while debugging  one code i got one interesting things ..let me explain you by bellow’s  example.

#include<stdio.h>
main()
{
int a=010;
printf("a is %d",a);
}

if you think output of this program will

“a  is  10″

then your are missing something….

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How to set, clear ,toggle and check a single bit in C?

JIGAR PATEL    c, sample programme, Tips     bit-wise operator

As being an embedded software engineer i would really suggest you this tricks. ..!  In many  application you need to deal with this bit wise operation. Sometimes you know this all stuff very well but still some time it takes  time to construct this logic or some time you got some mistakes in it. so i suggest you to paste this on your desk until you paste this in your mind..!

 number |= 1 << x;