[Python-Dev] Issue 11406: adding os.scandir(), a directory iterator returning stat-like info

[Antoine Pitrou]

Le Fri, 10 May 2013 15:46:21 +0200,
Christian Heimes <christian at python.org> a écrit :

> Am 10.05.2013 14:16, schrieb Antoine Pitrou:
> > But what if some systems return more than the file type and less
> > than a full stat result? The general problem is POSIX's terrible
> > inertia. I feel that a stat result with some None fields would be
> > an acceptable compromise here.
> 
> POSIX only defines the d_ino and d_name members of struct dirent.
> Linux, BSD and probably some other platforms also happen to provide
> d_type. The other members of struct dirent (d_reclen, d_namlen)
> aren't useful in Python space by themselves.
> 
> d_type and st_mode aren't compatible in any way. As you know st_mode
> also contains POSIX permission information. The file type is encoded
> with a different set of bits, too. Future file types aren't mapped to
> S_IF* constants for st_mode.

Thank you and Ronald for clarifying. This does make the API design a
bit bothersome. We want to expose as much information as possible in a
cross-platform way and with a flexible granularity, but doing so might
require a gazillion of namedtuple fields (platonically, as much as one
field per stat bit).

> For d_ino you also need the device number from the directory because
> the inode is only unique within a device.

But hopefully you've already stat'ed the directory ;)

Regards

Antoine.