思路：关键在于建立两个有名管道，利用多线程技术，进程A中线程1向管道A写数据，进程B中线程2从管道A读数据，进程A线程2从管道B中读数据，进程B中线程1往管道B中写数据
//线程和FIFO练习
//pthreadtest.c#include <stdio.h>#include <pthread.h>#include <stdlib.h>#include <unistd.h>#include <sys/types.h>#include <fcntl.h>#include <sys/stat.h>#include <errno.h>#include <string.h>int global = 2;int fd;#define FIFO_NAME "/home/book/watchman/fifotest"void* pthread1_handler(void* temp){ int fd = open(FIFO_NAME,O_WRONLY|O_NONBLOCK,0);// int ret; if(fd < 0) { perror("pthread1 open"); printf("pthread1 open err\n"); pthread_exit((void*)-1); } // ret = getchar(); printf("pthread1 going write fifo\n"); write(fd,"test1",5); printf("pthread1 write fifo ok\n"); global++; getchar(); write(fd, "test",4); printf("i'm phread1,global=%d!\n",global); pthread_exit((void *)5); printf("i'm pthread1,printf twice\n");}void * pthread2_handler(void* temp){ char buf[10]; int ret; /* // int fd = open(FIFO_NAME,O_RDONLY,0); if((fd <0) &&(errno!=EEXIST)) { perror("pthread2 open"); printf("pthread2 open err\n"); pthread_exit((void *)-1); } */ printf("i'm read fifo\n"); ret = read(fd,buf,5); if(ret < 0) { printf("pthread2 read"); pthread_exit((void *)-1); } printf("%s\n",buf); printf("i'm read fifo2\n"); memset(buf,0,sizeof(buf)); ret = read(fd,buf,5); if(ret < 0) { printf("pthread2 read"); pthread_exit((void *)-1); } printf("%s\n",buf); global++; printf("i'm pthread2,global=%d\n",global);}int * pthread3_handler(void * parg){ printf("i'm pthread3\n");}int main(int argc,char * argv[]){ pthread_t pthread1; pthread_t pthread2; pthread_t pthread3; int ret; umask(0); ret = mkfifo(FIFO_NAME,0777); if((ret < 0)&&(errno != EEXIST)) { perror("mkfifo"); printf("mkfifo err\n"); exit(1); } fd = open(FIFO_NAME,O_RDONLY|O_NONBLOCK,0); if(fd < 0) { perror("main process open"); exit(1); } ret = pthread_create(&pthread1,NULL,pthread1_handler,NULL); if(ret < 0) { perror("pthread_create"); exit(1); } printf("wait for pthread1\n"); ret = 0; sleep(1); pthread_join(pthread1,(void **)&ret); printf("pthread1 ret=%d\n",ret); global++; printf("i'm in parent pthread global=%d\n",global); ret = pthread_create(&pthread2,NULL,pthread2_handler,NULL); if(ret < 0) { perror("pthread_create2"); exit(1); } printf("wait for pthread2\n"); if((ret = pthread_join(pthread2,NULL)) < 0) { printf("pthread_join pthread2 err\n"); } printf("wait for pthread2 over\n"); /* ret = pthread_create(&pthread3,NULL,pthread3_handler,NULL); if(ret < 0) { perror("pthread_create3"); exit(1); }*/}
编译
book@ubuntu:~/watchman$ gcc -pthread -o pthreadtest.o pthreadtest.c book@ubuntu:~/watchman$