NetNews Usenet Archive 1992 #31/NN_1992_31.iso/spool/comp/os/vms/19985

Internet Message Format | 1992-12-29 | 2.4 KB

Path: sparky!uunet!gatech!usenet.ins.cwru.edu!agate!ucbvax!U.WASHINGTON.EDU!DEREK
From: [e-mail]
Newsgroups: comp.os.vms
Subject: Re: Detecting directory of invoked .com
Message-ID: <[e-mail]>
Date: 28 Dec 92 19:16:00 GMT
Sender: [e-mail]
Distribution: world
Organization: The Internet
Lines: 49

Carl Fogelin ([e-mail]) asked:

>In a DCL program, I would like to be able to determine what directory the
>invoked .com file is located in.

Several people gave solutions to Carl's problem by suggesting the use of
the F$ENVIRONMENT() lexical function, e.g., F$ENVIRONMENT("PROCEDURE").
A couple of respondents indicated that you can use the F$PARSE() lexical
function to easily extract the DIRECTORY portion of the returned file
specification.

(One side note: of the eight responses I have seen to date, only Jamie
Hanrahan included any humor.  Good job, Jamie!)

Although a few posters also mentioned using F$PARSE() to extract the
DEVICE portion of the file-spec, no one really was specific as to WHY
this information might be useful.  The point is that the DIRECTORY name
may not supply sufficient information to distinguish between the two
installations.  For example, if the test code is in DISK$TEST:[CARL] and
production code is in DISK$PRODUCTION:[CARL], then in is clear that you
ALSO need to know the DEVICE names.


Nonetheless, the answers are still incomplete.  It may be that the device
name used is something like PRODUCT$DEVICE:[CARL], where the definition
of PRODUCT$DEVICE is different for the two installations.  The better
solution, I would think, would be to use the NO_CONCEAL argument to the
F$PARSE() lexical function.  For example, try the following five line
command procedure and compare the output.

$ write sys$output f$parse(f$env("procedure"),,,"device")
$ write sys$output f$parse(f$env("procedure"),,,"directory")
$!
$ write sys$output f$parse(f$env("Procedure"),,,"device","no_conceal")
$ write sys$output f$parse(f$env("procedure"),,,"directory","no_conceal")

I am not going to claim that this is absolutely the BEST solution.  I
will, however, argue that it is a more complete solution that those which
have previously been offered.

-Derek S. Haining
 University Computing Services
 University of Washington
 Seattle, Washington  98195
 [phone]

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