Elm and XENIX

[Chip Salzenberg]

I've been using Elm 1.7 beta for some months now under SCO Xenix/286
(versions 2.1.x and 2.2.x).

WARNING FOR XENIX USERS RUNNING ELM:  As distributed, Elm creates mail
lock files in the _wrong place_:

	Locking style           Lockfile name
	-------------           -----------------------------
	V7 (used by Elm)        /usr/spool/mail/username.lock
	Xenix                   /tmp/username.mlk

You must change Elm's locking code (and fastmail and filter, if you use
them) to reflect this difference.  Otherwise you run the risk of corrupting
your mailbox when new mail comes in.

In article <150 at amcad.UUCP> billb at amcad.UUCP (Bill Burton) writes:
>I have been recently attempting to get Elm 1.7 working on SCO Xenix 286
>and it appears that I have succeded for the most part.  The one problem
>is that occaisionally I get a "Segment Violation" and sometimes a core
>dump.  This happens if I use the "builtin" pager, or when I try and save
>the configuration options. 

Try looking at stack backtrace after the core dump (the adb "$c" command).
That should give you a hint.

>Have compiled with the following flags (if I remember correctly):
>	CC: -O -Ml2 -Mt24 -LARGE
>	LD: -Ml2 -F 4000

I used "128" instead of "24", otherwise the same.

>Here is a brief list of some of the changes I made:
>o   hdrs/sysdefs.h: ifdefs for locations of mail directory, rmail and vi
>    using M_XENIX define
>o   modified Makefile's for appropriate compiling flags above
>o   Chmod 777 /usr/spool/mail
>o   Chmod 600 /usr/spool/mail/*
>o   src/encode.c - added a dummy crypt() function so ld would't
>    complain.  Encryption should be ifdef-able.

Chmod 777 is a BAD IDEA.  Do you want other people removing _your_ mail
file?  Instead make /usr/spool/mail 775 and make Elm setgid bin.  Then Elm
can write to that directory but hostile users can't.  (And Elm does check
for your real permissions, so other users can't just use Elm to read your
mail.)

>Elm is a great program (thanks, Dave!)

Hear, hear.

[Eight-line signature deleted; shame on you, Bill!]

-- 
Chip Salzenberg                "chip at ateng.UU.NET" or "codas!ateng!chip"
A T Engineering                My employer may or may not agree with me.
  "I must create a system or be enslaved by another man's." -- Blake