《Linux應用實例教程》課件-講義30并發(fā)程序-管道通信

S10、并發(fā)程序-管道通信S10、并發(fā)程序-管道通信S10、并發(fā)程序-管道通信1、匿名管道#include<stdlib.h>#include<stdio.h>#include<unistd.h>intwc=1,rc=1; S10、并發(fā)程序-管道通信voidwriter(constchar*message,intcount,FILE*stream){ for(;count>0;--count){ fprintf(stream,"%s:%d\n",message,wc); sprintf(wstr,"%s:%d\n",message,wc); fflush(stream); printf("第%d次寫入管道的內(nèi)容為：%s",wc,wstr); wc++; sleep(1);

}}S10、并發(fā)程序-管道通信voidreader(FILE*stream){//讀管道stream，次數(shù)為rc charbuffer[1024]; while(!feof(stream)&&!ferror(stream)&&fgets(buffer,sizeof(buffer),stream)!=NULL) {//從管道stream讀取消息存入buffer緩沖區(qū) printf("讀進程第%d次讀?。?,rc); rc++; fputs(buffer,stdout); //輸出所讀管道信息 }}S10、并發(fā)程序-管道通信intmain(){ intfds[2]; pid_tpid; pipe(fds);//創(chuàng)建匿名管道 pid=fork(); //創(chuàng)建子進程 if(pid==(pid_t)0){//子進程代碼 FILE*stream; close(fds[1]); //關閉管道寫端 stream=fdopen(fds[0],"r"); //子進程以只讀方式打開管道 reader(stream);//子進程讀取管道 close(fds[0]); //子進程關閉讀端 }S10、并發(fā)程序-管道通信 else{ //父進程代碼 FILE*stream; close(fds[0]); //關閉管道讀端 stream=fdopen(fds[1],"w"); //父進程以只寫方式打開管道 writer("Hello,world.",5,stream); //父進程向管道寫入5次消息“Hello,world.” close(fds[1]); //子進程關閉寫端 } return0;}S10、并發(fā)程序-管道通信編譯鏈接：gccpipec.c-opipec運行：./pipecS10、并發(fā)程序-管道通信2、有名管道通信管道寫程序fifo_write.c：#include<stdio.h>#include<stdlib.h>#include<string.h>#include<sys/types.h>#include<sys/stat.h>#include<errno.h>#include<unistd.h>#include<fcntl.h>#defineFIFO"myfifo"http://有名管道名字#defineBUFF_SIZE1024S10、并發(fā)程序-管道通信intmain(intargc,char*argv[]){charbuff[BUFF_SIZE];//欲寫入管道的數(shù)據(jù)緩沖區(qū)intreal_write; //寫入管道的字節(jié)數(shù)intfd; //管道描述符intrw=1; //管道寫次數(shù)if(access(FIFO,F_OK)==-1){//測試有名管道FIFO是否存在，若不存在，則用mkfifo創(chuàng)建該管道if((mkfifo(FIFO,0666)<0)&&(errno!=EEXIST)){//創(chuàng)建管道"myfifo"，允許讀寫printf("CanNOTcreatefifofile!\n");exit(1);}}S10、并發(fā)程序-管道通信if((fd=open(FIFO,O_WRONLY))==-1){//調(diào)用open以只寫方式打開FIFO，返回文件描述符fdprintf("Openfifoerror!\n");exit(1);}do{printf("請輸入要寫入管道的內(nèi)容：");gets(buff); if((real_write=write(fd,buff,BUFF_SIZE))>0)printf("第%d次寫入管道:'%s'.\n",rw++,buff);}while(strlen(buff)!=0);close(fd);exit(0);}S10、并發(fā)程序-管道通信管道讀程序fifo_read.c：#include<stdio.h>#include<stdlib.h>#include<string.h>#include<sys/types.h>#include<sys/stat.h>#include<errno.h>#include<unistd.h>#include<fcntl.h>#defineFIFO"myfifo" //有名管道名字#defineBUFF_SIZE1024S10、并發(fā)程序-管道通信intmain(){charbuff[BUFF_SIZE]; //欲讀取管道的數(shù)據(jù)緩沖區(qū)intreal_read; //讀取管道的字節(jié)數(shù)intfd; //管道描述符intrc=1; //管道讀次數(shù)if(access(FIFO,F_OK)==-1){//測試有名管道FIFO是否存在，若不存在，則用mkfifo創(chuàng)建該管道if((mkfifo(FIFO,0666)<0)&&(errno!=EEXIST)){//創(chuàng)建管道"myfifo"，允許讀寫printf("CanNOTcreatefifofile!\n");exit(1);}}S10、并發(fā)程序-管道通信if((fd=open(FIFO,O_RDONLY))==-1){//以只讀方式打開FIFO，返回文件描述符fdprintf("Openfifoerror!\n");exit(1);}while(1){//循環(huán)讀管道，若讀空，則結(jié)束循環(huán)memset(buff,0,BUFF_SIZE); if((real_read=read(fd,buff,BUFF_SIZE))>0) printf("第%d次讀取管道:'%s'.\n",rc