[ILUG] don't pass open file descriptor to children

[kevin lyda]

On Fri, Jul 13, 2001 at 04:07:54PM +0100, Glen Gray wrote:
> I'd suggest using clone instead of fork but IIRC it globally restricts
> descriptors being passed to children, i.e. It doesn't give you fine
> control to pass all but this descriptor etc.

it also makes you code linux-only.  a better solution is to...

> On 13 Jul 2001 16:05:02 +0100, Padraig Brady wrote:
> > Is there a flag you can set on a file descriptor (using fcntl or equivalent)
> > to tell the kernel not to copy that particular descriptor to forked 
> > children?

...do this:

    fd_only_in_parent=open(...)
    ...
    pid=fork();
    if (pid == -1) {
	...
    } else if (pid == 0) {
	/* do parent things */
    } else {
	close(fd_only_in_parent);
	/* do child things */
    }

have a lot of fd's you only want in the parent?  put them into an array,
and have the kids loop them close.

kevin

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