detect . in a/.//

Corinna Vinschen corinna-cygwin@cygwin.com
Wed Sep 30 15:55:00 GMT 2009


On Sep 30 11:34, Christopher Faylor wrote:
> bool
> has_dot_last_component (const char *dir, bool test_dot_dot)
> {
>   /* SUSv3: . and .. are not allowed as last components in various system
>      calls.  Don't test for backslash path separator since that's a Win32
>      path following Win32 rules. */
>   const char *last_comp = strrchr (dir, '\0');
> 
>   if (last_comp == dir)
>     return false;       /* Empty string.  Probably shouldn't happen here? */
> 
>   /* Detect run of trailing slashes */
>   while (last_comp > dir && *--last_comp == '/')
>     continue;
> 
>   /* Detect just a run of slashes or a path that does not end with a slash. */
>   if (*last_comp != '.')
>     return false;
> 
>   /* We know we have a trailing dot here.  Check that it really is a standalone "."
>      path component by checking that it is at the beginning of the string or is
>      preceded by a "/" */
>   if (last_comp == dir || *--last_comp == '/')
>     return true;
> 
>   /* If we're not checking for '..' we're done.  Ditto if we're now pointing to
>      a non-dot. */
>   if (!test_dot_dot || *last_comp != '.')
>     return false;               /* either not testing for .. or this was not '..' */
> 
>   /* Repeat previous test for standalone or path component. */
>   return last_comp == dir || last_comp[-1] == '/';
> }

Looks good to me.  Easier to understand than the current code.


Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Project Co-Leader          cygwin AT cygwin DOT com
Red Hat



More information about the Cygwin-patches mailing list