實(shí)驗(yàn)五:管道通信實(shí)驗(yàn)內(nèi)容：.閱讀以下程序：inc1ude<unistd.h>inc1ude<stdio.h>incIude<stdlib.h>main()(intfiledes[2];charbuffer[80]；if(pipe(filedes)<0)//建立管道,filedes[0]為管道里的讀取端，filedes[1]則為管道的寫入端//成功則返回零，否則返回?1,錯(cuò)誤因素存于errno中err_quit(/zpipeerror");f(fork()>0){chars[]=Mhello!\n”;c1ose(filedes[0]);//關(guān)閉filedes[0]文獻(xiàn)write(filedes[l],s,sizeof(s))：〃s所指的內(nèi)存寫入到fi1edes[1]文獻(xiàn)內(nèi)close(filedes[1])；//關(guān)閉filedes⑼文獻(xiàn)}else{close(filedes[l]);read(fiIedes[0],buffec80);//把filedes⑼文獻(xiàn)傳送80個(gè)字節(jié)到buffer緩沖區(qū)內(nèi)printf("%s”,buffer)；close(fi1edes[0]);編譯并運(yùn)營程序，分析程序執(zhí)行過程和結(jié)果，注釋程序重要語句。#include<unistd.h>#include<stdio.h>/Include<stdltb.h>main()(tntftledes[2];charbuffer[80];if(ptpe(filedes)<0)//err_quit(,,pipeerrorw);printf("pipeerror");if(fork()>0){chars[]="hello!\n"；close(filedes[0]);write(filedes[l],s,sizeof(s));close(filedes[l]);}else{close(ftledes[l]);read(filedes[O],buffer,80);printfbuffer);close(ftledes[0]);))user@ubuntu:->vi5-1.cuser@ubuntu:-$gcc5-1.c-o5-1user@ubuntu:~$~/5-lhello!user@ubuntu:-$-/5-lhello!use「@ubuntu:~$,.閱讀以下程序:include<sys/types.h>inc1ude<sys/stat.h>incIude<fcntl.h>main()charbuffer[80];intfd；un1ink(FIFO);〃刪除FIFO文獻(xiàn)mkfifo(FlFO,0666);I3//FIF0是管道名,0666是權(quán)限if(fork()>0){chars[]="he1lo!\n"；fd=open(FIFO,O_WRONLY);//以只寫方式打開文獻(xiàn)F1FOwrite(fd,s/sizeof(s));//把字符數(shù)組s的內(nèi)存寫入sizeof(s)個(gè)字節(jié)到參數(shù)fd所指的文獻(xiàn)內(nèi)close(fd);〃關(guān)閉該文獻(xiàn),dose()會(huì)讓數(shù)據(jù)寫回磁盤,并釋放該文獻(xiàn)所占用的資源}e1se{fd=open(FIFO,O_RDONLY);read(fd,buffer,80);printf("%s〃,buffer)；c1ose(fd)；)編譯并運(yùn)營程序，分析程序執(zhí)行過程和結(jié)果,注釋程序重要語句。#tnclude<stdto.h>#tnclude<sys/types.h>#include<sys/stat.h>#tnclude<fcntl.h>main(){charbuffer[80];intfd;unlink(M5-2M)；mkfifo(H5-2H,0666);〃FIFO:5-2是管道名，0666是權(quán)限tf(fork()>0){chars[]="hello!\nM;fd=open(H5-2M,O_WRONLY);wrtte(fd,s,sizeof(s));close(fd);}else{fd=open("5-2H,0_RD0NLY);read(fd,buffer,80);printf(H%sH,buffer);close(fd);))user@ubuntu:-$gcc5-2.c-o5-2user@ubuntu:~$~/5?2hello!use「@ubuntu:~$,.閱讀以下程序：#include<stdio.h>main()FILE*fp;charbuffer[80];fp=popen(Mcat/etc/passwd","r")；/*調(diào)用fork。產(chǎn)生子進(jìn)程,然后從子進(jìn)程中調(diào)用/bin/sh-c來執(zhí)行cat/etc/passwd。參數(shù)代表讀取，popen()會(huì)建立管道連到子進(jìn)程的標(biāo)準(zhǔn)輸出設(shè)備或標(biāo)準(zhǔn)輸入設(shè)備，然后返回一個(gè)文獻(xiàn)指針。*/fgets(buffer,sizeoffbuffer),fp);〃從fp文獻(xiàn)中讀取sizeof(buffer)-1個(gè)字符到bufferprintf("%s”,buffer);pc1ose(fp)；//關(guān)閉文獻(xiàn)fp)編譯并運(yùn)營程序，分析程序執(zhí)行過程和結(jié)果，注釋程序重要語句。#include<stdio.