Select loop in linux - how to make it better?

Question

I have select with N pipe, my problem: After catch ,,one" pipe - select don't work. Probably I don't remove i descriptor. And here is my questions:
1) Do I really have to make dynamic array like vector in C and insert and remove i
2) How to make my code better? How Can I solve problem with select?

My code:

while(1)
        {
                sel = select(val+1,&set,NULL,NULL,&timeout);

                if(sel < 0)
                        perror("Blad funkcji select");
                else if(sel == 0)
                        printf("Brak komunikatow \n");
                else{

                        for(i = 0; i < val; i++)
                        {
                                if(FD_ISSET(fd[i][0],&set))
                                {
                                   while(read(fd[i][0],&buf,rozmiar) > 0)
                                   write(1,&buf,rozmiar);


                                } // check if exist and write to stdout


                } // end SELECT
                for(i = 0, j =0; i< val; i++)
                {
                        FD_SET(fd[i][0], &set);

                }

                timeout.tv_sec = 4;
                timeout.tv_usec = 0;
        }

Answer 1

RETURN VALUE top

   On success, select() and pselect() return the number of file
   descriptors contained in the three returned descriptor sets (that is,
   the total number of bits that are set in readfds, writefds,
   exceptfds) which may be zero if the timeout expires before anything
   interesting happens.  On error, -1 is returned, and errno is set to
   indicate the error; the file descriptor sets are unmodified, and
   timeout becomes undefined.

 if(sel ==-1)
                perror("Blad funkcji select");