#include "stdio.h"

void main()
{char ch;
FILE *fp,*fm; /*fp用来标记源文件,fm用来标记加(解)密文件*/
fp=fopen("e:\\en.txt","rt");
fm=fopen("e:\\mima.txt","wt+");

while ((ch=fgetc(fp))!=EOF)
{
ch=ch^255; /*用原来的字符异或255来加解密*/
fputc(ch,fm); /*把加密后的字符保存到文件指针fm所指向的文件*/
}

fclose(fp);
fclose(fm);

}

#include "stdio.h"

int main()
{char ch,source[40],aim[40];
FILE *fp,*fm; /*fp用来标记源文件,fm用来标记加(解)密文件*/
clrscr();
puts("qing shu ru jia\\jie mi wen jian de lu jin.\nru: c:\\en.txt");
/*请输入加\解密文件的路径:*/
gets(source);
puts("qing shu ru jia\\jie mi yi hou de wen jian de lu jin:\nru: c:\\mima.txt");
/*请输入加\解密后的文件的路径:*/
gets(aim); /*gets不支持\转义自符*/

fp=fopen(source,"rt");
fm=fopen(aim,"wt+");

if (fp==NULL || fm==NULL)
{ printf("\nCannot open file strike any key exit!");
getch();
exit(1);
}

while ((ch=fgetc(fp))!=EOF)
{
ch=ch^255; /*用原来的字符异或255来加解密*/
fputc(ch,fm);
}

fclose(fp);
fclose(fm);
getch();

}