Path: utzoo!attcan!uunet!nih-csl!lhc!ncifcrf!haven!udel!princeton!njsmu!mccc!shevett
From: shevett@mccc.uucp (Dave Shevett)
Newsgroups: comp.databases
Subject: Re: rlock() in SCO foxbase+.
Keywords: foxbase, rlock
Message-ID: <1990Sep25.234729.5299@mccc.uucp>
Date: 25 Sep 90 23:47:29 GMT
References: <553@safn2.UUCP> <79@mq.COM>
Reply-To: shevett@mccc.edu (Dave Shevett)
Organization: The College On The Other Side of U. S. Route 1
Lines: 44

In article <79@mq.COM> alan@mq.COM (Alan H. Mintz) writes:
=In article <553@safn2.UUCP>, rey@safn2.UUCP (rey) writes:
=> Set up is SCO Unix 3.2.2 on Compaq 386. SCO Foxbase+.
=> 
=> Could some one please explain rlock() in foxbase+. I am converting 
=> Dbase single user programs.
=>
=> I think the answer is a). When I rlock() then call another
=> 	procedure I cannot append. But that doesn't seem correct design.
=
=APPENDs require flock() (which cannot be performed on a file that is rloc()d
=by another user. Note that you can flock() a file in which YOU have rlocked
=a record - the flock() simply supercedes the rlock().

Careful here.  The 'append' function standalone requires a flock().
However, I think 'rey' is running inside a procedure, therefore is 
probably doing APPEND BLANK.  In this case, the normal sequence is:

Build your screen using memory variables, and READ it.
append blank
if rlock()
	replace etc etc etc etc
	unlock
else
	do error with "Can't lock that sucker"
endif

=< Alan H. Mintz             | Voice +1 714 980 1034       >
=< Micro-Quick Systems, Inc. | FAX   +1 714 944 3995       >
=< 10384 Hillside Road       | uucp:     ...!uunet!mq!alan >
=< Alta Loma, CA  91701 USA  | Internet: alan@MQ.COM       >

On another tack - has anyone seen 'Invalid Signal Received' cropping up
when returning to a function called after a READ MENU TO mVAR 
function?  It happens 5 out of 7 times on a customer's machine, and
it's *EXTREMELY* annoying.  How about getting an error 'Feature Not
Available' at the same point, eh? (oh - SCO Xenix 2.3.1, SCO Fox
2.1.1, '386/20 w/4megs RAM, DigiBoard/8i)

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