操作系统文件加密

编程实现文件加密
 1 #include<stdio.h>
 2 #include<unistd.h>
 3 #include<fcntl.h>
 4 void main()
 5 {
 6     int fd1,fd2;
 7     char ch;
 8     if((fd1=open("5.txt",O_RDONLY))!=-1)
 9     {
10         if((fd2=open("6.txt",O_WRONLY))!=-1)
11         {
12             while(read(fd1,&ch,1)==1)
13             {
14                 ch=ch^'a';
15                 write(fd2,&ch,1);
16               
17             }
18             printf("5.txt加密成功，加密文件为6.txt
");
19         }
20         close(fd2);
21     }
22    close(fd1);
23     if((fd1=open("6.txt",O_RDONLY))!=-1)
24     {
25         if((fd2=open("7.txt",O_WRONLY))!=-1)
26         {
27             while(read(fd1,&ch,1)==1)
28             {
29                 ch=ch^'a';
30                 write(fd2,&ch,1);
31             }
32             printf("6.txt解密成功，解密文件为7.txt
");
33         }
34         close(fd2);
35     }
36     close(fd1);
37 }