topic LIB$SET_LOGICAL in Operating System - OpenVMS

LIB$SET_LOGICAL

Rizwan Latheef — Wed, 26 Sep 2007 11:43:58 GMT

Iam using lib$set_logical to set a logical in a OPENVMS Basic programme. First time this sets the logical but it does not redefines the logical if it is already set. What needs to be done inorder to redefine the logical if it is already set?
SYS_STATUS = LIB$SET_LOGICAL(RETURN_PRINTQ,WORK::T_PRINTQ,"LNM$PROCESS")

Re: LIB$SET_LOGICAL

Steven Schweda — Wed, 26 Sep 2007 12:17:05 GMT

What is your SYS_STATUS result when the
thing fails?

Re: LIB$SET_LOGICAL

Dean McGorrill — Wed, 26 Sep 2007 12:30:23 GMT

what is the status returned on the second
define? also as I remember you can pass an
item list with this call. ( don't remember what the attributes you can set ) Dean

Re: LIB$SET_LOGICAL

Rizwan Latheef — Wed, 26 Sep 2007 12:38:56 GMT

When I examined it in debug I got
before the execution of the comand I got
SYS_STATUS: 1 and after I got
SYS_STATUS: 1585

Re: LIB$SET_LOGICAL

Dean McGorrill — Wed, 26 Sep 2007 12:42:00 GMT

$ write sys$output f$message(%D1585)
%SYSTEM-S-SUPERSEDE, logical name superseded
$

it would appear it replaced the logical
for you! Dean

Re: LIB$SET_LOGICAL

Rizwan Latheef — Wed, 26 Sep 2007 13:12:16 GMT

It was expecting "RETURN_PRINTQ" in quotes. When I added quotes it worked.

Re: LIB$SET_LOGICAL

Jan van den Ende — Wed, 26 Sep 2007 13:18:23 GMT

Rizwan,

on thamking those that helped you in this forum, please review

http://forums1.itrc.hp.com/service/forums/helptips.do?#33

-- for this as well as your previous questions.

Proost.

Have one on me.

jpe

Re: LIB$SET_LOGICAL

Hoff — Wed, 26 Sep 2007 13:22:04 GMT

When system calls go bad or when unexpected behavior arises, the debugger and a small test program can be invaluable.

Create a dozen-line test program -- I have a suspicion that this BASIC sequence is buried in a far larger application -- and then spend some time with the code and the debugger and (for this case) with the SHOW LOGICAL /FULL command.

I'd here wonder if there are any odd characters in the logical name string, or if there is a requirement for a trusted logical name (eg: something else looking at this logical name is running with privileges; the process table isn't easily accessible from installed and privileged code for instance), or if there is a logical name definition "ahead" of this one somewhere in the logical name tables. Either based on the translation table order, or the access mode. (Some of these details can be ascertained with the SHOW LOGICAL /FULL command. Others with the test program.)

Stephen Hoffman
HoffmanLabs LLC