有名管道可以用于任何两个程序间通信，因为有名字可引用。注意管道都是单向的，因此双方通信需要两个管道。
下面分别是这两个程序代码,同样是Lucy先运行,然后是Peter。
fifoLucy.c
#include<sys/types.h>#include<sys/stat.h>
#include<stdio.h>#include<errno.h>#include<fcntl.h>#include<string.h>#include<unistd.h>#include<stdlib.h>
int main(){char write_fifo_name[] = "lucy"; char read_fifo_name[] = "peter"; int write_fd, read_fd; char buf[256]; int len; struct stat stat_buf;
int ret = mkfifo(write_fifo_name, S_IRUSR | S_IWUSR); if( ret == -1) { printf("Fail to create FIFO %s: %s",write_fifo_name,strerror(errno)); exit(-1); }
write_fd = open(write_fifo_name, O_WRONLY); if(write_fd == -1) { printf("Fail to open FIFO %s: %s",write_fifo_name,strerror(errno)); exit(-1); } while((read_fd = open(read_fifo_name,O_RDONLY)) == -1) { sleep(1); } while(1) { printf("Lucy: "); fgets(buf, 256, stdin); buf[strlen(buf)-1] = ‘/0’; if(strncmp(buf,"quit", 4) == 0) { close(write_fd); unlink(write_fifo_name); close(read_fd); exit(0); } write(write_fd, buf, strlen(buf)); len = read(read_fd, buf, 256); if( len > 0) { buf[len] = ‘/0’; printf("Peter: %s/n", buf); } }}
fifoPeter.c
#include<sys/types.h>#include<sys/stat.h>#include<string.h>#include<stdio.h>#include<errno.h>#include<fcntl.h>#include<stdlib.h>
int main(void){char write_fifo_name[] = "peter"; char read_fifo_name[] = "lucy"; int write_fd, read_fd; char buf[256]; int len;
int ret = mkfifo(write_fifo_name, S_IRUSR | S_IWUSR); if( ret == -1) { printf("Fail to create FIFO %s: %s",write_fifo_name,strerror(errno)); exit(-1); }
while((read_fd = open(read_fifo_name, O_RDONLY)) == -1) {sleep(1); } write_fd = open(write_fifo_name, O_WRONLY); if(write_fd == -1) { printf("Fail to open FIFO %s: %s", write_fifo_name, strerror(errno)); exit(-1); }
while(1) { len = read(read_fd, buf, 256); if(len > 0) { buf[len] = ‘/0’; printf("Lucy: %s/n",buf); } printf("Peter: "); fgets(buf, 256, stdin); buf[strlen(buf)-1] = ‘/0’; if(strncmp(buf,"quit", 4) == 0) { close(write_fd); unlink(write_fifo_name); close(read_fd); exit(0); } write(write_fd, buf, strlen(buf)); }}
使你疲倦的不是前面的高山，而是你鞋里的一粒沙子。
