bug#37702: Suggestion for 'df' utility

[John Pye]

Hi all

My vote would be on a "df -a" switch to revert to original behaviour of
visibility of all mounts.

The purpose of "df" is to show "disk free". Hence any filesystems that
are read-only or which are FUSE-mounted one on of the local physical
filesystems, or similar things (what others?) should be suppressed by
default.

Perhaps a message could be included in the new output to indicate that
some filesystems are suppressed, and "df -a" can be used to see all
mounted filesystems. That would allow people to 'autodiscover' the new
default functionality. That message could be kept in place for a few
years, or even indefinitely. The output message could be sent to stderr,
to allow people to continue to pipe the main "df" output into "wc -l" or
"awk" or whatever other unix-style tools they might like to use.

Perhaps it might be hard to decide what to do with network filesystems,
or locally-caching Amazon S3 filesystems, or whatever things like
that... I am sure there are some tricky corner cases that would need to
be considered.

Cheers
JP

On 31/5/20 9:07 am, Paul Eggert wrote:
> On 5/30/20 4:49 AM, Erik Auerswald wrote:
>> I concur that a command line option to override config file (or env var)
>> settings seems useful if a config file and/or env var approach is used.
> In other utilities we've been moving away from environment variables and/or
> config files for the usual security and other-hassle reasons. So I'd prefer
> having 'df' just do the "right" thing by default, and to have an option to
> override that. The "right" thing should be to ignore all these 
> pseudofilesystems
> that hardly anybody cares about.