Re: Porting uptimed: Usage of daemon and replacement of NOFILE

[Guillem Jover]

On Tue, 2011-11-01 at 15:57:53 +0100, Svante Signell wrote:
> Updated code snippet below, OK?
> 
> void bg(void)
> {
>         int i, fdmax;
[...]
>         /* Close probably all file descriptors */
> #ifdef __USE_BSD
>         if ((fdmax = getdtablesize()) == -1) exit(1);
> #else
>         if ((fdmax = sysconf(_SC_OPEN_MAX)) == -1) exit(1);
> #endif
>         for (i = 0; i<fdmax; i++)
>                 close(i);
[...]
> }

__USE_BSD is an internal macro used by glibc and should not be relied
on. Add a check to configure.ac instead, something like this:

AC_CHECK_FUNCS([getdtablesize])

and then use HAVE_GETDTABLESIZE. Also if there's no limit (-1) it's a
bit harsh to exit(1). I'd code this for example like:

,---
void bg(void)
{
        int i, fdmax;
[...]
#ifdef HAVE_GETDTABLESIZE
        fdmax = getdtablesize();
#else
        fdmax = sysconf(_SC_OPEN_MAX);
#endif
        if (fdmax <= 0)
                fdmax = 3;

        for (i = 0; i < fdmax; i++)
                close(i);
[...]
}
`---

regards,
guillem