SAS generated LIBREF.

[data_null__]

The following code will generate a LIBREF named as MC0000nn.  But I cannot figure out how to know the generated name.  The FILENAME function has similar feature that populates the variable with the generated FILEREF.

6
7    data _null_;
8       length libref $8;
9       libref = ' ';
10      rc = libname(libref,'.');
11      msg = sysmsg();
12      put _all_;
13      run;

libref=  rc=-70004 msg=NOTE: Libref  refers to the same physical library as SASUSER. _ERROR_=0 _N_=1
NOTE: DATA statement used (Total process time):
      real time           0.01 seconds
      cpu time            0.01 seconds

SASHELP.VLIBNAM before and after.

BeforeAfter

[ChrisNZ]

Not too sure why you'd want to define a nameless library, but you can get the name by defining another library that points to the same location:

data _null_;
  length LIBREF $8;
  LIBREF = ' ';
  RC  = libname(LIBREF,'.');
  RC  = libname(LIBREF,'.');
  MSG = sysmsg();
  put _all_;
run;

LIBREF= RC=-70004 MSG=NOTE: Libref refers to the same physical library as WC000001. _ERROR_=0 _N_=1

A bit wasteful but better than nothing?