25 May
2003
25 May
'03
1:08 p.m.
From: Dennis Ritchie <dmr(a)plan9.bell-labs.com>
To: tuhs(a)minnie.tuhs.org
Subject: [TUHS] (no subject)
Date: Fri, 23 May 2003 00:10:30 -0400
Thanks for confirming this. In fact, the V7 calculation is only
an approximation in another sense; a file with large holes could
generate too large a result.
System III doesn't have st_nblocks either.
The V7 ls(1) man page says that the -s option,
which prints total
blocks, includes any indirect blocks.
However, the V7 struct stat didn't have the
st_blocks member in the
struct stat, and the code in ls.c uses
long
nblock(size)
long size;
{
return((size+511)>>9);
}
So, is this just a case of the man page being
mistaken?
Yes, it looks like a manual bug. Retrieving
the true number of indirect blocks isn't possible
from the 7th edition stat. I'm not sure when (or by
whom) the st_blocks member was added. While I'm
at it, the V7 ls -a option only adds . and .. to the
list; apparently all other dot files were printed by default.
When did ls change such that -a applied to all dot files?
UCB or USL did this (I'm sure which first).
Both tended to use more . files.
Dennis