Re: cd // produces unexpected results

[Stefano Lattarini]

On 06/22/2012 09:47 PM, Chet Ramey wrote:
>> By accident I keyed in :
>>
>> cd //
>>
>> and noticed that my prompt included both slashes.
> 
> Posix says shells have to leave two leading slashes in a pathname alone.
> Three or more can be collapsed to one, but two have to stay unchanged.
> This has come up multiple times in the past.
> 
A little more info, quoting from the Autoconf manual:

  POSIX lets implementations treat leading // specially, but requires leading
  /// and beyond to be equivalent to /.  Most Unix variants treat // like /.
  However, some treat // as a "super-root" that can provide access to files
  that are not otherwise reachable from /.  The super-root tradition began
  with Apollo Domain/OS, which died out long ago, but unfortunately Cygwin
  has revived it.

HTH,
  Stefano