Re: bugs in dirname module

[Eric Blake]

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According to Paul Eggert on 11/9/2005 2:19 PM:
> 
> However: what happens in DOS if you use a file name like "@:/a/b/c"?

In DOS, : is an invalid character, so the file name is outright rejected
when passed to a function that actually visits the disk.  But POSIX
requires that basename(1) and dirname(1) operate even in the presence of
invalid file names, without checking for existance or legality.

On cygwin, : can be a valid file character (cygwin has managed mounts,
where cygwin transparently translates the names in use by the program into
valid characters for the file system).  There, drive letters are exactly
[A-Za-z]:, and all other leading characters (besides slashes, of course),
are treated as a relative pathname from ./ rather than a drive designator.

> Is this parsed as an invalid file letter, and then rejected, or as a
> file name that's much like "@_/a/b/c" but just happens to have an
> colon rather than an underscore?  If the former, then surely dirname
> should not bother to check whether the first character is a letter.

Dirname really does need to check the first character for correctness on
cygwin.

- --
Life is short - so eat dessert first!

Eric Blake             address@hidden
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