弹出警告Microsoft Visual C++ Debug Library fgets.c 报错解决办法

Microsoft Visual C++ Debug Library 

Program:C:\WINDOWS\system32\PicsUU.scr
File:fgets.c 
Line:60  

Expression:str !=NULL 

For information on your program can cause an assertion failure,see the Visual C++ documentation on asserts.  

(Press Retry to debug the application)

void NONO()
{/* 本函数用于打开文件，输入数据，调用函数，输出数据，关闭文件。 */
  FILE *fp, *wf ;
  int i;  long r;
  char s[10], *p;

  fp = fopen("c:\\test\\in.dat","r") ;
  wf = fopen("c:\\test\\out.dat","w") ;
  for(i = 0 ; i < 10 ; i++) {
    fgets(s, 10, fp);
    p = strchr(s, ‘\n‘);
    if (p) *p = 0;
    r = fun(s);
    fprintf(wf, "%ld\n", r);
  }
  fclose(fp) ;
  fclose(wf) ;
}

void NONO()
{/* 本函数用于打开文件，输入数据，调用函数，输出数据，关闭文件。 */
  FILE *fp, *wf ;
  int i;  long r;
  char s[10], *p;

  fp = fopen("C:\\EXAM\\00000000\\prog1\\in.dat","r") ;
  wf = fopen("C:\\EXAM\\00000000\\prog1\\out.dat","w") ;
  for(i = 0 ; i < 10 ; i++) {
    fgets(s, 10, fp);
    p = strchr(s, ‘\n‘);
    if (p) *p = 0;
    r = fun(s);
    fprintf(wf, "%ld\n", r);
  }
  fclose(fp) ;
  fclose(wf) ;
}

void NONO()
{/* 本函数用于打开文件，输入数据，调用函数，输出数据，关闭文件。 */
  FILE *fp, *wf ;
  int i;  long r;
  char s[10], *p;

  fp = fopen("..\\in.dat","r") ;
  wf = fopen("..\\out.dat","w") ;
  for(i = 0 ; i < 10 ; i++) {
    fgets(s, 10, fp);
    p = strchr(s, ‘\n‘);
    if (p) *p = 0;
    r = fun(s);
    fprintf(wf, "%ld\n", r);
  }
  fclose(fp) ;
  fclose(wf) ;
}