Why /etc/mtab? (was: Example modification of /etc/mtab wanted)

[Lyndon Nerenberg]

[ Followups in comp.unix.questions ]

summer at atreides.trl.oz.au (Mark Summerfield - Switching) writes:

>The problem is that using mount() doesn't add an entry to /etc/mtab, so
>other commands (such as df, and umount) don't know about the
>filesystem.

Which leads me to pose the question:

	Why does Unix use a file to store mount information?

It seems to me that the proper way to determine what's mounted would
be to look in the kernel mount tables. It would be trivial to implement
a system call to return the information. Anyone know why the "ask the
kernel" approach was never taken?
-- 
      Lyndon Nerenberg  VE6BBM / Computing Services / Athabasca University
          {alberta,cbmvax,mips}!atha!lyndon || lyndon at cs.athabascau.ca
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