[c-prog] Re: error checking

[John Matthews]

--- In c-prog@yahoogroups.com, John Gaughan <[EMAIL PROTECTED]> wrote:
>
> When in doubt, casting NULL seems to work for me.

Assuming the OP is using C (filename is p.c), if you need to cast NULL
then something is wrong.

If the code is:

#include <stdio.h>

int main(void) 
{
   char a[]="hello\n";
   FILE *fp;
   fp = fopen("file","a");
   if (fp == NULL) {
     puts("fopen error");
     exit(1);
   }

   return 0;
}

Compile under linux using gcc 4.1.2:

> gcc -Wall p.c
p.c: In function `main':
p.c:10: warning: implicit declaration of function `exit'
p.c:10: warning: incompatible implicit declaration of built-in
function `exit'
p.c:5: warning: unused variable `a'

Can you paste the whole code, compiler command line and output?

John