文件系统的用户界面[含答案]

#include <sys/stat.h> #include <sys/fcntl.h> #include <stdio.h> #define BUF_1_MB 1024 #define BUF_1_B 1 main() { int fd1,fd2; int n; char buf1[BUF_1_B],buf2[BUF_1_MB],buf3[BUF_1_B],buf4[BUF_1_MB]; FILe *fp1,*fp2; fd1=open("file1",O_RDONLY); fd2=open("file2",O_WRONLY|O_CREAT|O_EXEC,0644); while((n=read(fd1,buf1,BUF_1_B))>0) { write(fd2,buf1,n); } n=0; while((n=read(fd1,buf2,BUF_1_MB))>0) { write(fd2,buf2,n); } fp1=open("file1",r); fp2=open("file3",w); while((n=fread(buf3,BUF_1_B,1,fp1))>0) { fwrite(buf3,BUF_1_B,1,fp2); } while((n=fread(buf4,BUF_1_MB,1024,fp1))>0) { fwrite(buf4,BUF_1_MB,1024,fp2); } }