不知道怎么回事，我写了个文件读取的小程序，读取到一定的行数后读出来的数据是错误的。大家看看是怎么回事。
代码：
#include<stdio.h>
int main()
{
    FILE *fp;
    FILE *fp_out;
    //char gch;
    char ch_x[]  =    {'0','1','2','3',
            '4','5','6','7',
            '8','9','a','b',
            'c','d','e','f'};
    int k;
    int i;
    char p_ch=0x1;
    char ch;
    fp=fopen("shudepb.exe","r");
    if(fp==NULL)
    {
        printf("file open error !!");
        //exit(0);
    }
    fp_out=fopen("out.txt","w");
    if(fp_out==NULL)
    {
        printf("file open error !!");
        //exit(0);
    }
    k=0;
    do
    {
        ch=fgetc(fp);
        fprintf(fp_out,"%d\t%c%c\t",k,ch_x[(ch&0x00f0)>>4],ch_x[ch&0x000f]);
        for(i=7;i>=0;i--)
        {       if((p_ch<<i)&ch)
            fprintf(fp_out,"1");
            else fprintf(fp_out,"0");
        }
        fprintf(fp_out,"\n");
        k++;
    }while(k!=5000);
}