HEADS DOWN

[Sean C. Farley]

On Thu, 3 May 2007, Andrey Chernov wrote:

> On Wed, May 02, 2007 at 11:08:18PM -0500, Sean C. Farley wrote:
>>  On Wed, 2 May 2007, Daniel Eischen wrote:
>>
>>> On Wed, 2 May 2007, Sean C. Farley wrote:
>>
>>  <snip>
>>
>>>> 2. getenv() sets errno to EINVAL and returns NULL if given a bad
>>>>    name to find.  setenv() and unsetenv() perform the same check on
>>>>    the name; should not getenv() do the same?  The check is easy to
>>>>    remove.
>>>
>>> I don't think getenv() should set errno.  The fact that it
>>> returns NULL is sufficient and POSIX doesn't define any errors
>>> for it.
>>
>>  Fixed for errno.  Also, no value is appropriate for errno when the
>>  name does not exist.  How about the feature that getenv() returns a
>>  NULL for a bad name instead of allowing a core dump?  Is that
>>  acceptable?
>
> Speaking about POSIXed error checking in *env() you can look at my
> backed out implemetation (via cvs diff), you may find it useful for
> you.

I believe I check all that you did in your changes.  Mine looks a little
different since some checks were combined for speed (i.e.,
__strleneq()).

The only other question I have is about leading whitespace in the name
passed to *env():
1. Should it be removed up to the first non-whitespace character?
2. Treated as part of the variable name.  Is this allowed by the
    specification?
3. Return errno = EINVAL.  getenv() would just return NULL.

I am leaning towards #2 since it may be desired by a developer.  If
"FOO BAR" is valid, why not " FOOBAR"?  I see that /usr/bin/env
currently allows it.

If #2 is good, then I think my code is functionally complete.  This is
of course not counting any hiding bugs.  :)

Sean
-- 
sean-freebsd at farley.org