Path: utzoo!utgpu!water!watmath!clyde!rutgers!gatech!bloom-beacon!tut.cis.ohio-state.edu!uwmcsd1!ig!agate!ucbvax!BRANDEIS.BITNET!SUTTON
From: SUTTON@BRANDEIS.BITNET
Newsgroups: comp.os.vms
Subject: RE: DCL problems
Message-ID: <8803271338.AA15277@ucbvax.Berkeley.EDU>
Date: 21 Mar 88 16:55:00 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 52

The problem you were having has to do with the characteristics of the :=
operator.  The "'s are optional with this kind of assignment.  If you leave
them out, the equivalence string is converted to upper case, multiple
spaces and tabs are reduced to one space and leading and trailing spaces
are removed.  The & operator is not parsed when it's used on the right side
of := or when embedded in a string, but the ' operator is.  That is why you
got "&P2" (notice that the "p" is uppercase and "count" did get translated
correctly).  Perhaps DCL skips the second phase of command processing for
:= statements?  The answer to your problem is to use the = and == operators
instead.  Here's a rewrite:

    $ p2 = "filename"
    $ count = 2
    $ temp = p'count
    $ t1 = temp
    $ show symbol t1

or

    $ p2 = "filename"
    $ count = 2
    $ show symbol p'count

The place to use the & operator is when you need to pass a symbol as part
of a "command":

    $ p2 = "*.*"
    $ count = 2
    $ directory &p'count

You know, I remember these rules more by instinct than by rote.  Anyway,
I stick to using := and :== to make alliases for commands in my LOGIN.COM
file:

    $ dr :== directory/date/protection
    $ com :== @com:compile.com x
        .
        .
        .

SUTTON@BRANDEIS.BITNET

P.S. One more tip.  If you want to find out if a symbol exists, (that is,
if you got to the end of the parameters), say:

    $ loop1: if f$type(p'count).eqs."" then goto end_loop1
        .
        .
        .
    $     count = count+1
    $     goto loop1
    $ end_loop1: