c - Linux 中的 Select 循环——如何让它变得更好？

Question

我选择了 N 个管道，我的问题是:捕获后，一个"pipe - 选择不起作用。可能我没有删除 i描述符。这是我的问题:
1) 我真的必须在 C 中创建像 vector 这样的动态数组并插入和删除 i
2)如何让我的代码更好？如何解决 select 的问题？

我的代码:

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");