On 20 March 2011 22:47, bd satish wrote:
> Hi,
>
> I'm trying to close a file using fclose, but the following program seg-faults:
>
>
> #include <stdio.h>
>
> int main(void)
> {
> FILE* fp = fopen("unfounded.txt", "r");
>
> if(fp == NULL)
> fclose(fp);
>
> return 0;
> }
>
>
> The file I'm trying to open doesn't exist in the directory, so fp is
> indeed NULL. So it's just fclose(NULL).
> Is fclose(NULL) legal according to the C standard ? As an end-user I
> expect fclose(fp) to close the file (if it is already open) or just do
> nothing (if it is not open). So the seg fault -- is this a compiler
> bug ?
>
> PS: I hope this is the right place to ask this question.
It's not, this mailing list is for development of gcc, not help using
it or help with C programming questions. Help using GCC can be sought
on the gcc-h...@gcc.gnu.org mailing list but in this case you'd be
better with a general C programming forum. Please take any follow up
questions to a more suitable place, thanks.
fclose() is provided by your system's C library, not the compiler, so
it wouldn't be a compiler bug anyway.
However fclose() requires a non-NULL pointer, so the problem is in
your code. If the file pointer is null the file wasn't opened so
there's nothing to close.
