IO进程线程8月22日
1，思维导图
2，使用read和write实现文件拷贝
#include<myhead.h>
int main(int argc, const char *argv[])
{int fp1,fp2;char a[1];fp1=open("./1.txt",O_RDONLY);fp2=open("./2.txt",O_CREAT|O_TRUNC|O_WRONLY,0664);if(fp1==-1||fp2==-1){perror("open");return -1;}int c;while(c=read(fp1,a,sizeof(a))){if(write(fp2,a,sizeof(a))!=c){break;}}close(fp1);close(fp2);fp2=open("./2.txt",O_RDONLY);if(fp2==-1){perror("open");return -1;}char n;while(read(fp2,&n,sizeof(a)){printf("%c",n);}close(fp2);return 0;
}