多路转接之poll和select，转接之pollselect

多路转接之poll和select，转接之pollselect

先看poll()：

1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <string.h> 4 #include <sys/stat.h> 5 #include <sys/types.h> 6 #include <fcntl.h> 7 #include <poll.h> 8 9 #define oops(x, n) { perror(x); exit(n); } 10 11 int main() 12 { 13 mkfifo("fifo1", 0644); 14 mkfifo("fifo2", 0644); 15 16 int fd1 = open("fifo1", O_RDWR); 17 int fd2 = open("fifo2", O_RDWR); 18 char buf[1000]; 19 for(;;) 20 { 21 struct pollfd pfd[] = {{0, POLLIN}, {fd1, POLLIN}, {fd2, POLLIN}}; 22 int ret = poll(pfd, 3, 1); 23 if(ret > 0) 24 { 25 if(pfd[0].revents&POLLIN) 26 { 27 scanf(" %[^\n]", buf); 28 printf("keypad:%s\n", buf); 29 if(strcmp(buf, "quit") == 0) break; 30 } 31 if(pfd[1].revents&POLLIN) 32 { 33 int n = read(fd1, buf, sizeof(buf)); 34 buf[n] = '\0'; 35 printf("fifo1:%s", buf); 36 } 37 if(pfd[2].revents&POLLIN) 38 { 39 int n = read(fd2, buf, sizeof(buf)); 40 buf[n] = '\0'; 41 printf("fifo2:%s", buf); 42 } 43 } 44 45 } 46 close(fd1); 47 close(fd2); 48 unlink("fifo1"); 49 unlink("fifo2"); 50 51 return 0; 52 } View Code

再来说说select()：

1 #include <stdio.h> 2 #include <stdlib.h> 3 #include <string.h> 4 #include <sys/stat.h> 5 #include <sys/types.h> 6 #include <fcntl.h> 7 #include <poll.h> 8 9 #define oops(x, n) { perror(x); exit(n); } 10 11 int main() 12 { 13 mkfifo("fifo1", 0644); 14 mkfifo("fifo2", 0644); 15 16 int fd1 = open("fifo1", O_RDWR); 17 int fd2 = open("fifo2", O_RDWR); 18 char buf[1000]; 19 for(;;) 20 { 21 struct pollfd pfd[] = {{0, POLLIN}, {fd1, POLLIN}, {fd2, POLLIN}}; 22 int ret = poll(pfd, 3, 1); 23 if(ret > 0) 24 { 25 if(pfd[0].revents&POLLIN) 26 { 27 scanf(" %[^\n]", buf); 28 printf("keypad:%s\n", buf); 29 if(strcmp(buf, "quit") == 0) break; 30 } 31 if(pfd[1].revents&POLLIN) 32 { 33 int n = read(fd1, buf, sizeof(buf)); 34 buf[n] = '\0'; 35 printf("fifo1:%s", buf); 36 } 37 if(pfd[2].revents&POLLIN) 38 { 39 int n = read(fd2, buf, sizeof(buf)); 40 buf[n] = '\0'; 41 printf("fifo2:%s", buf); 42 } 43 } 44 45 } 46 close(fd1); 47 close(fd2); 48 unlink("fifo1"); 49 unlink("fifo2"); 50 51 return 0; 52 } View Code