#include <stdio.h>
#include <string.h>
#include <conio.h>
FILE *fi,*fo;
int i;
int main(int argc,char **argv) {
    if (argc<3) {
        printf("Usage:%s src des\n",argv[0]);
        return 1;
    }
    if (0==stricmp(argv[1],argv[2])) {
        printf("Src and des is same!\n");
        return 2;
    }
    fo=fopen(argv[2],"wb");
    if (NULL==fo) {
        printf("Can not create file %s\n",argv[2]);
        return 3;
    }
    fi=fopen(argv[1],"rb");
    if (NULL==fi) {
        fclose(fo);
        printf("Can not find file %s\n",argv[1]);
        return 4;
    }
    i=0;
    fseek(fi,-1L,SEEK_END);
    while (1) {
        fputc(fgetc(fi)^0x5A,fo);
        i++;
        if (i%1000000==0) cprintf("\r%dKB",i/1000);
        if (fseek(fi,-2,SEEK_CUR)) break;
    }
    fclose(fi);
    fclose(fo);
    cprintf("\r%dKB OK.\r\n",i/1000);
    return 0;
}