Re: g_file_test()

[Owen Taylor <otaylor redhat com>]

Tim Janik <timj gtk org> writes:

> On Mon, 6 Aug 2001, Tim Janik wrote:
> 
> > 
> > typedef enum
> > {
> >   G_FILE_TEST_IS_REGULAR    = 1 << 0,
> >   G_FILE_TEST_IS_SYMLINK    = 1 << 1,
> >   G_FILE_TEST_IS_DIR        = 1 << 2,
> >   G_FILE_TEST_IS_EXECUTABLE = 1 << 3,
> >   G_FILE_TEST_EXISTS        = 1 << 4
> > } GFileTest;
> > 
> > gboolean g_file_test         (const gchar  *filename,
> >                               GFileTest     test);
> > 
> > having used g_file_test() in a couple places now, i have to say that:
> > 1) it definitely needs G_FILE_TEST_IS_READABLE and G_FILE_TEST_IS_WRITABLE
> > 2) it should return TRUE only if all tests succeeded.
> 
> are there actually any objections/concerns not yet raised on this issue?
> if not, i'd like to fix matters ASAP.

OK, the original discussion is at:

 http://mail.gnome.org/archives/gtk-devel-list/2000-October/msg00154.html

The primary concern that came up with making it all-of is that 
that would conflict with the current semantics of g_file_test()
in gnome-libs, which I think is 

I agree that all-of is more what I would expect, but I don't
think the any-of behavior is so ridiculous that I would be
willing to declare programs that expect it buggy. I think if
we change the behavior, we have to change the name.

(I'd think the reason why it's any-of is what you get when you
read:

 g_file_test (G_FILE_TEST_IS_REGULAR | G_FILE_TEST_IS_SYMLINK);

Yep, "test file is regular or file is symlink".)
  
Possibilities for an all-of name include:

 g_file_test_is_all ()
 g_file_test_all ()
 g_file_is_all ()
 g_file_is ()


I think G_FILE_TEST_IS_READABLE/IS_WRITEABLE are open to abuse, and
its pretty hard to get them exactly right, considering things like:

 - read-only mounts
 - Multiple groups for a user
 - ACLs on AFS
 - Behavior of access as root and with setuid

Basically, the only way to safely tell if you would be able
to read/write a file is to actually do it. 

Does that mean we shouldn't add them? It may be that if we don't,
people will write the tests themselves and do it worse.  I don't
know...

When do you see them being useful?

                                        Owen