#include<stdlib.h>
#include<conio.h>
#include<string.h>
void dofile(char *in_fname,char *pwd,char out_file)
{
FILE *fp1,*fp2;
register char ch;
int j=0;
int j0=0;
fp1=fopen(in_fname,"rb");
if(fp1==NULL)
{
printf("cannot open in-file.\n");
exit(1); //如果不能打開要加密的文件，便退出程序、
}
fp2=fopen(out_file,"wb");
if(fp2==NULL)
{
printf("cannot open or create out-file.\n");
exit(1); //如果不能建立加密後的文件，便退出
}
while(pwd[++j0]);
ch=fgetc(fp1); //加密算法開始
while(!feof(fp1))
{
fputc(ch^pwd[j>j0?j=0:j++],fp2); //異或後寫入fp2文件
ch=fgetc(fp1);
}
fclose(fp1);
fclose(fp2);
}
void main(int argc,char *argv[])
{
char in_fname[30];
char out_fname[30];
char pwd[8];
if(argc!=4)
{
printf("\nIn-fname:\n");
gets(in_fname);
printf("Password:\n");
gets(pwd);
printf("Out-file:\n");
gets(out_fname);
dofile(in_fname,pwd,out_fname);
}
else
{
strcpy(in_fname,argv[1]);
strcpy(pwd,argv[2]);
strcpy(out_fname,argv[3]);
dofile(in_fname,pwd,out_fname);
}
}