[comp.mail.misc] SCO mail system

root@chief.UUCP (Lance Ellinghouse) (12/21/88)

Does anyone know how the people at SCO lock their mail files
when they are scanned in by mail? I would like to write a similar
one that does not have the shell escape and I cannot figure out
what they use as a lock. DO they actually lock it, or do they use
a temp file?

Thanks,
Lance Ellinghouse

-- 
Lance Ellinghouse                        
Chief Numismatics, Inc
UUCP: ...!{hermix|srhqla|ucla-an|alphacm}!chief!lance
ARPA: ucla-an!hermix!chief!lance@ee.UCLA.EDU

dheller@cory.Berkeley.EDU (Dan Heller) (12/23/88)

In article <462@chief.UUCP> root@chief.UUCP (Lance Ellinghouse) writes:
> Does anyone know how the people at SCO lock their mail files
> when they are scanned in by mail? I would like to write a similar
> one that does not have the shell escape and I cannot figure out
> what they use as a lock. DO they actually lock it, or do they use
> a temp file?
> 
> Lance Ellinghouse                        
> Chief Numismatics, Inc
> UUCP: ...!{hermix|srhqla|ucla-an|alphacm}!chief!lance
> ARPA: ucla-an!hermix!chief!lance@ee.UCLA.EDU

SCO's xenix, unfortunately, uses a file locking mechanism which
is not available to the end user.  Execmail use a temp lock file
called /tmp/.mlkXXXXX to lock the file, but other things are done
as well, so just creating the file won't do.  The routine to lock
the file is not in a library; it's part of the source to execmail.
Probably someone at sco should elaborate on this, but the bottom
line is that writing your own mail user agent is tricky.  The best
you can do is to use lockf().

Dan Heller	<island!argv@sun.com>