bug#34309: coreutils v. 8.30 – Output ignores paths specified.

[Bernhard Voelker]

tag 34309 notabug
thanks

On 2/4/19 11:59 AM, Ricky Tigg wrote:
> bash v.4.4.23. Output ignores paths specified.Commands executed:
> 
> $ df -h
> Filesystem                Size  Used Avail Use% Mounted on
> devtmpfs                  1.9G     0  1.9G   0% /dev
> tmpfs                     1.9G   90M  1.8G   5% /dev/shm
> tmpfs                     1.9G  1.8M  1.9G   1% /run
> tmpfs                     1.9G     0  1.9G   0% /sys/fs/cgroup
> /dev/mapper/fedora-juuri   18G  7.2G  9.6G  43% /
> tmpfs                     1.9G   16K  1.9G   1% /tmp
> /dev/mapper/fedora-koti   894G  6.9G  842G   1% /home
> /dev/sda1                 976M  221M  689M  25% /boot
> tmpfs                     374M   44K  374M   1% /run/user/1000
> /dev/sdc1                 7.3G   34M  6.9G   1% /run/media/yk/USB
> 
> $ df -h /run/media/
> Filesystem      Size  Used Avail Use% Mounted on
________________________________________^^^^^^^^^^
> tmpfs           1.9G  1.8M  1.9G   1% /run

You asked 'df' to output the file system statistics the file/directory
"/run/media" is on.  As that directory is not a mount point by itself,
the tools goes up in the hierarchy and finds "/run" in the list
of mount points.  That's what it prints, and the column label there-
fore correctly is "Mounted on".

If you want to see the given argument value as well, you need to
specify/add the --output=file column, e.g.:

  $ df --output=source,pcent,target,file /run/user
  Filesystem     Use% Mounted on File
  tmpfs            1% /run       /run/user


> Expected result: since path '/run/media/' had been specified, a correct
> whole output would be
> 
> /dev/sdc1                 7.3G   34M  6.9G   1% /run/media/yk/USB

I don't understand: how would the tool know you want it to have statictics
for file system(s) mounted _below_ the given argument?  It doesn't work
in that direction ... it works the other way round (see above).

As such, I'm marking this as not a bug in our software.  Of course,
feel free to continue the discussion here.

Have a nice day,
Berny