Re: ls /dev

[Tomasz Wegrzanowski <maniek@beer.com>]

On Fri, Jul 28, 2000 at 01:36:01PM +0200, Marcus Brinkmann wrote:
> Linux proc never gives correct answers. We can't do this mistake, 
> because
> we rely on translators in the whole system.

If it did, there would be enormous overhead, because you can't
generate sizes without generating file content, and generating
file contents would last very long time (and couldn't be reasonably cached)

> But it is a good idea to make mc aware of Hurd features indeed.
> 
> You really have not swallowed the translator concept by heart. :)
> Only when you realize that there can't be any difference between a
> translator and a regular file in the POSIX interface, you will see
> why what the Hurd does is very sensible.

This is not translator/not-translator issue.

See examples :

1)
UI app is used to show number (+ size, maybe) of all files in every
subdirectory.

dir a is on ext2fs. dir b is on ftpfs.

How do you tell user app that it's ok to ckeck subdir a,
but not ok to check subdir b ?

2)
UI app is used to file sizes of all files in current directory.
(even more common)

file a is common file, file b is dynamically generated report.
(How they happened to be in the same directory ? 
 It might be weird translator, or shadowfs)

How do you tell user app that it's ok to ask for size of a,
but not ok to check for size of b ?

3)
dir a is on ftpfs. dir b is on the same ftpfs, but cached.

4)
dir a is on ftpfs from machine on different continent.
dir b is on ftpfs from machine connected to you by 100 Mbps ethernet.

There must be some way for program to tell this difference.
This has nothing to do with ``translatorness'' of the file.