Re: purpose of *-safer?

[Paul Eggert]

>> And wouldn't there be an easier workaround: At the beginning of main(),
>> use fcntl() to determine whether 0,1,2 are closed, and if so, replace
>> them with open("/dev/null") ?
>
> Possibly.  And if we did, it would make more sense to open fd 0 as write
> only and fd 1 as read only, to be more likely to catch attempts to use
> these streams when the user intended them to be closed.

Jim did that in coreutils/lib/stdopen.c, I think with the idea of
migrating it into gnulib if there was demand.  Hmm, but this code
currently isn't being used in coreutils.  I don't offhand recall why.

Here's what I do recall.  I swept coreutils for the sort of problem
that stdopen would cure and fixed then with stdio-safer etc.  Jim
wrote stdopen.c in response, since this would be simpler than all
those painstaking sweeps.

If I missed nothing in my sweeps (an unlikely prospect!), then
invoking stdopen merely adds a small amount of bloat to coreutils, and
is unnecessary.  A more-important argument against stdopen is that
weird invocations like "cat /dev/fd/2 2>&-" would do the wrong thing.