IO进程线程 240826作业
作业
创建3个进程,子进程1拷贝文件的前一半,子进程2拷贝后一半文件,父进程回收两个子进程资源。
将1.txt内容拷贝到2.txt中
#include <myhead.h>
int main(int argc, const char *argv[])
{pid_t pid1;pid1 = fork();int fd1 = open("./1.txt",O_RDWR);if(fd1==-1){perror("open");return -1;}int fd2 = open("./1.txt",O_RDWR);if(fd2==-1){perror("open");return -1;}int fd3 = open("./2.txt",O_RDWR);if(fd3==-1){perror("open");return -1;}if(pid1==0){char buf[100];int len = read(fd1,buf,sizeof(buf));write(fd3,buf,len/2);printf("拷贝成功\n");}else if(pid1>0){pid_t pid2;pid2 = fork();if(pid2==0){char buf[100];int len = read(fd2,buf,sizeof(buf));lseek(fd2,len/2,SEEK_SET);int len1 = read(fd2,buf,sizeof(buf));lseek(fd3,len/2,SEEK_SET);write(fd3,buf,len1);printf("拷贝成功\n");}else if(pid2>0){wait(NULL);wait(NULL);exit(EXIT_SUCCESS);}}else{perror("fork");return -1;}return 0;
}运行结果：
知识梳理
进程
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