将d1复制到d2中，复制要求出英文和数字外的其他内容

Question

#include<stdio.h>
#include<stdlib.h>
int main()
{
char ch;
FILE *fp;
FILE *pf;
fp=fopen("E:\d1.txt","r");
pf=fopen("E:\d2.txt","w");
if(fp==NULL||pf==NULL)
{
printf("错误");
exit(0);
}
ch=fgetc(fp);
while(ch!=EOF)
{
if(('a'>=ch&&ch<='z')||('A'>=ch&&ch<='Z')||('0'>=ch&&ch<='9'))
putchar(ch);
else
{
fputc(ch,pf);
}
ch=fgetc(fp);
}
fclose(fp);
fclose(pf);
return 0;
}为什么运行出来不对头运行出来的结果是英文字母到了d2数字和其他符号显示在了屏幕上

Answer 1

打开文件的两句修改为：
fp=fopen("E:\\d1.txt","r"); //fp=fopen("E:\d1.txt","r");
pf=fopen("E:\\d2.txt","w"); //pf=fopen("E:\d2.txt","w");