Date:         Thu, 10 Feb 2005 11:22:44 -0500
Reply-To:     "Richard A. DeVenezia" <radevenz@IX.NETCOM.COM>
Sender:       "SAS(r) Discussion" <SAS-L@LISTSERV.UGA.EDU>
From:         "Richard A. DeVenezia" <radevenz@IX.NETCOM.COM>
Subject:      Re: Creating a dataset without step boundaries in Base SAS

m n wrote:
> Dear SAS-L,
>
> I developed a simple macro that finds a unique data
> set name in the WORK directory (to avoid clashes for
> temporary data sets), and I want the macro to create a
> 0 obs 0 variable placeholder data set so that on
> future invocations the macro won't return the same
> "unique" name.
>
> In SCL, the open() function has an 'N' mode for
> creating a new dataset, but it doesn't seem to work
> for the Base SAS version of open() (at least for
> v8.0).  Is there any other way of creating a data set
> with out a step boundary (i.e. without data _null_;
> stop; run;)?  I want to avoid the step boundary so
> that the macro can be treated as a function, emitting
> the unique name as in:
>
> %let TMP = %get_uniq_dsn();

I am unaware of a Base SAS function or call routine that creates a table.
SCL functions COPY and RENAME are also not in Base.

There is a way though.  Use the operating system to copy the underlying
files of the table.
This crude example demonstrates the idea.  Not robust.

data null;
  stop;
run;

%macro copyViaOs (src, dst);

  * only works for librefs that are _not_ concatenated paths;

  %let syslast = &src;

  %let srclib = %scan (&syslast,1,.);
  %let srcmem = %scan (&syslast,2,.);

  %let syslast = &dst;
  %let dstlib = %scan (&syslast,1,.);
  %let dstmem = %scan (&syslast,2,.);

  %let srcpth = %sysfunc(pathname(&srclib));
  %let dstpth = %sysfunc(pathname(&dstlib));

  %let oscmd = copy &srcpth.\&srcmem..* &dstpth.\&dstmem..*;

  %put &oscmd;
  %sysexec (&oscmd);

%mend;

data classes;
  set sashelp.class;
run;

proc sql; drop table work.class; quit;

%put EXISTS? %sysfunc(exist(WORK.CLASS));
options noxwait xsync xmin;  * xsync is important;
%copyViaOs (classes, class);
%put EXISTS? %sysfunc(exist(WORK.CLASS));


%copyViaOs (null, %myNewUniqueName);

--
Richard A. DeVenezia
http://www.devenezia.com/