Path: utzoo!attcan!uunet!cs.utexas.edu!asuvax!ncar!ico!rcd
From: rcd@ico.isc.com (Dick Dunn)
Newsgroups: comp.unix.i386
Subject: Re: extended file names
Summary: no
Message-ID: <1990Mar26.220005.27452@ico.isc.com>
Date: 26 Mar 90 22:00:05 GMT
References: <511363@nstar.UUCP>
Organization: Interactive Systems Corporation, Boulder, CO
Lines: 24

larry@nstar.UUCP (Larry Snyder) writes:
> Is there a way to modify the kernel (386/ix) to increase the length
> of file names to 18 characters?  

No.  It's not theoretically impossible; it's just highly impractical.  And
you'd need source for a fair bit of the kernel.

Why 18???  The current (also ancient, time-honored) limit of 14 is used
because it is two less than a power of two; the two remaining bytes contain
the i-number of the file.  This lets a whole number of (fixed-size)
directory entries fit in a file-system block.  The next logical increase,
if you were to retain the current structure, would be a name limit of 30
bytes.  That wouldn't be terribly hard to do, but it would be tedious...
and you'd need kernel source to do it.

Even if you could make such a change, the conversion would be painful,
since you'd be introducing a new file system type.  There are some
"genesis" problems (booting old style to install new, converting old to
new).  When you finished, you'd have a file system which would be
incompatible with both old AT&T 14-fixed-length style and BSD flexname-
style.
-- 
Dick Dunn     rcd@ico.isc.com    uucp: {ncar,nbires}!ico!rcd     (303)449-2870
   ...Relax...don't worry...have a homebrew.