Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!husc6!sri-unix!hplabs!sdcrdcf!psivax!csun!sdsu!dlong
From: dlong@sdsu.UUCP
Newsgroups: comp.os.minix
Subject: Looks like bug in head.c
Message-ID: <2545@sdsu.UUCP>
Date: Tue, 24-Feb-87 20:25:50 EST
Article-I.D.: sdsu.2545
Posted: Tue Feb 24 20:25:50 1987
Date-Received: Sat, 28-Feb-87 00:52:24 EST
Reply-To: dlong@sdsu.UUCP (mostly harmless)
Distribution: world
Organization: San Diego State University, Math/Sciences Dept.
Lines: 26

This is on a Leading Edge PC, but it should apply to all.
Looking at commands/head.c, I noticed that the routine that
reads a line (do_line I think) only checks for '\n', not EOF.
That could explain the strange things that happened when I
tried "head" on a file shorter than the default.  For example:
"head commands/sync.c"  causes problems since sync.c is about 3
lines long.  After the sync.c is listed, nothing happens for a while,
then comes the weird stuff.  At 8Mhz I got an error that goes something
like this:

Unexpected trap:vector >= 16 This may be due to ... non-MINIX library
routine that is trying to make a system call
pc = 0x4955   text+data+bss = 0xB780

Also, there was static on the screen, as if something was poking around
in screen memory.

At 4Mhz, I only got the screen static.  This time it was not continuous, but
cycled on and off every second or so.
I both cases, I had to reboot.  I realize that most people probably don't
have there hands on the floppies yet, so you can't try this, though you could
verify what I said about about head.c by looking in the book.
-- 
Dean Long
San Diego State Univ.
sdcsvax!sdsu!dlong