多路转接之poll和select

先看poll()：

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <fcntl.h>
 #include <poll.h>

 #define oops(x, n) { perror(x); exit(n); }

 int main()
 {
     mkfifo("fifo1", );
     mkfifo("fifo2", );    

     int fd1 = open("fifo1", O_RDWR);
     int fd2 = open("fifo2", O_RDWR);
     char buf[];
     for(;;)
     {
         struct pollfd pfd[] = {{, POLLIN}, {fd1, POLLIN}, {fd2, POLLIN}};
         int ret = poll(pfd, , );
         if(ret > )
         {
             if(pfd[].revents&POLLIN)
             {
                 scanf(" %[^\n]", buf);
                 printf("keypad:%s\n", buf);
                 if(strcmp(buf, "quit") == ) break;
             }
             if(pfd[].revents&POLLIN)
             {
                 int n = read(fd1, buf, sizeof(buf));
                 buf[n] = '\0';
                 printf("fifo1:%s", buf);
             }
             if(pfd[].revents&POLLIN)
             {
                 int n = read(fd2, buf, sizeof(buf));
                 buf[n] = '\0';
                 printf("fifo2:%s", buf);
             }
         }

     }
     close(fd1);
     close(fd2);
     unlink("fifo1");
     unlink("fifo2");

     return ;
 }

再来说说select()：

 #include <stdio.h>
 #include <stdlib.h>
 #include <string.h>
 #include <sys/stat.h>
 #include <sys/types.h>
 #include <fcntl.h>
 #include <poll.h>

 #define oops(x, n) { perror(x); exit(n); }

 int main()
 {
     mkfifo("fifo1", );
     mkfifo("fifo2", );    

     int fd1 = open("fifo1", O_RDWR);
     int fd2 = open("fifo2", O_RDWR);
     char buf[];
     for(;;)
     {
         struct pollfd pfd[] = {{, POLLIN}, {fd1, POLLIN}, {fd2, POLLIN}};
         int ret = poll(pfd, , );
         if(ret > )
         {
             if(pfd[].revents&POLLIN)
             {
                 scanf(" %[^\n]", buf);
                 printf("keypad:%s\n", buf);
                 if(strcmp(buf, "quit") == ) break;
             }
             if(pfd[].revents&POLLIN)
             {
                 int n = read(fd1, buf, sizeof(buf));
                 buf[n] = '\0';
                 printf("fifo1:%s", buf);
             }
             if(pfd[].revents&POLLIN)
             {
                 int n = read(fd2, buf, sizeof(buf));
                 buf[n] = '\0';
                 printf("fifo2:%s", buf);
             }
         }

     }
     close(fd1);
     close(fd2);
     unlink("fifo1");
     unlink("fifo2");

     return ;
 }