#include "stdio.h"
main()
{
    FILE * fp;
    char ch;
    if((fp=fopen("file1.txt","w")==NULL))
    {
       printf("cannot open file\n");
       exit(0);
    }
    while((ch=getchar())!='\n')
 fputc(ch,fp);
    fclose(fp);
}
运行以后我输入一些字符，结果却是NULL PIONTER ASSIGNMENT请问是怎么回事啊

if((fp=fopen("file1.txt","w")==NULL))
改成
if((fp=fopen("file1.txt","w"))==NULL)

我真是态粗心了，谢谢！！！