用C语言编写程序建立一个pipe

1、用C语言编写程序，建立一个pipe, 同时父进程生成一个子进程，子进程向pipe写入一个字符串”Hello.”，父进程从pipe中读取该字符串。

5'#include <stdio.h>#include <stdlib.h>#include <string.h>#include <errno.h>#include <unistd.h>#include <sys/wait.h>int main(){char buf[20];int piledes[2];pid_t pid;int ret;if(ret = pipe(piledes) == -1){perror("error on pipe:");exit(-1);}else{pid = fork();if(pid < 0){perror("error on fork:");exit(-1);}else if(pid == 0){close(piledes[0]);printf("to fu:");fgets(buf,sizeof(buf)-1,stdin);if((ret = write(piledes[1],buf,strlen(buf))) < 0){perror("error on writing:");exit(-1);}close(piledes[1]);}else{close(piledes[1]);if((ret = read(piledes[0],buf,sizeof(buf)-1)) < 0){perror("error on reading:");exit(-1);}buf[ret] = '\0';printf("from zi:%s\n",buf);close(piledes[0]);}}return 0;}2、编写一个 C语言程序lswc，使之功能能和ls | wc 等价。

(也就是利用，fork,exec,以及ls,wc，以及重定向，或者是管道的系统调用) 13’#include <stdio.h>#include <sys/types.h>#include <sys/socket.h>#include <netinet/in.h>#include <arpa/inet.h>#include <netdb.h>#include <string.h>#include <unistd.h>#include <stdlib.h>#include <sys/wait.h>#include <sys/stat.h>#include <errno.h>#include <fcntl.h>#include <string.h>int main(int argc,char *argv[]){int pildes[2];int ret;char *argument[3];pid_t pid;char buf[1000];if(argc < 2){printf("que shao can shu\n");exit(0);}argument[0] = "ls";argument[1] = "/";argument[2] = NULL;if((ret = pipe(pildes)) < 0){perror("error on pipe:");exit(-1);}pid = fork();if(pid <0){printf("fork error\n");exit(-1);}if(pid == 0){close(pildes[0]);dup2(pildes[1],1);execvp("ls",argument);close(pildes[1]);}else{close(pildes[1]);// dup2(fildes[0],0);if(strcmp((argv[1]),"wc") == 0){bzero(buf,sizeof(buf));if((ret = read(pildes[0],buf,sizeof(buf))) < 0){printf("error on reading:");exit(-1);}buf[ret] = '\0';printf("%s",buf);close(pildes[0]);}}return 0;}3、实现一个具有头节点的链表。

要求具有create, insert, delete, search功能，能对链表。

编写一个应用程序，使用上面的函数。

10'#include <stdio.h>#include <string.h>#include <stdlib.h>#include <error.h>#define PASSWD 111111struct student{int num;char name[20];float grade;struct student *next;};typedef struct student stuNode;typedef struct student *stuPtr;int stuwrite(stuPtr head){FILE *fp;fp = fopen("stu","w");while(head->next != NULL){head = head->next;fwrite(head,sizeof(stuNode),1,fp);}close(fp);return 0;}stuPtr sturead(){FILE *fp;stuPtr head,p1,p2;int a;head = (stuPtr)malloc(sizeof(stuNode));head->next = NULL;p1 = head;fp = fopen("stu","r");do{p2 = (stuPtr)malloc(sizeof(stuNode));p2->next = NULL;a = fread(head,sizeof(stuNode),1,fp);p1->next = p2;p1 = p2;}while(a == 1);fclose(fp);return head;}void creat(){stuPtr head,p;head = (stuPtr)malloc(sizeof(stuNode));p = (stuPtr)malloc(sizeof(stuNode));p->next = NULL;head->next = p;printf("学号：");scanf("%d",&(p->num));getchar();printf("姓名：");scanf("%s",p->name);getchar();printf("成绩：");scanf("%f",&(p->grade));getchar();stuwrite(head);}stuPtr insert(stuPtr head){stuPtr p,q;p = (stuPtr)malloc(sizeof(stuNode));printf("学号：");scanf("%d",&(p->num));getchar();printf("姓名：");scanf("%s",p->name);getchar();printf("成绩：");scanf("%f",&(p->grade));getchar();q = head;while(q->next != NULL && p->num > q->next->num) {q = q->next;}p->next = q->next;q->next = p;stuwrite(head);p = sturead();return p;}stuPtr search(stuPtr head,int num){stuPtr p1,p2;int flag;p1 = (stuPtr)malloc(sizeof(stuNode));p2 = (stuPtr)malloc(sizeof(stuNode));p1 = head;while(p1->next != NULL){flag = 0;p2 = p1;p1 = p1->next;if(p1->num == num){flag = 1;break;}}if(flag == 1){p1 = p2;return p1;}else{printf("没有此人\n");return NULL;}}stuPtr delete(stuPtr head, int num) {stuPtr p1,p2;int flag;p1 = search(head,num);p2 = p1->next;p1->next = p2->next;free(p2);stuwrite(head);p1 = sturead();return p1;}void print(stuPtr head){stuPtr p;int i;printf("学号\t姓名\t成绩\n");p = head->next;while(p != NULL){if(p->num >0 && p->grade >0){printf("%d\t%s\t%.1f\n",p->num,p->name,p->grade);}p = p->next;}}void print1(stuPtr p){printf("学号\t姓名\t成绩\n");while(p != NULL){if(p->num >0 && p->grade >0){printf("%d\t%s\t%.1f\n",p->num,p->name,p->grade);}p = p->next;}}int main(){int choose,num;stuPtr head,p;head = (stuPtr)malloc(sizeof(stuNode));p = (stuPtr)malloc(sizeof(stuNode));while(1){printf("1\t创建链表\n2\t添加节点\n3\t删除节点\n4\t查找学生\n5\t查看所有学生信息\n0\t退出\n");scanf("%d",&choose);switch(choose){case 1:creat();break;case 2:head = sturead();insert(head);break;case 3:head = sturead();printf("删除学生的学号：");scanf("%d",&num);delete(head,num);break;case 4:head = sturead();printf("学生学号：");scanf("%d",&num);p = search(head,num);p = p->next;print1(p);break;case 5:head = sturead();print(head);case 0:break;default:break;}}return 0;}。