REALNAME CSECT ,       Rexx function to return next gdg or
REALNAME AMODE 31      the real name of a data set alias
REALNAME RMODE ANY            syntax: Say REALNAME(dsname)
         STM   14,12,12(13)
         LR    12,15
         USING REALNAME,12
         USING EVALBLOCK,2
         L     9,20(1)         r2 = address rexx eval block
         L     2,0(,9)
         LA    3,EVALBLOCK_EVDATA r3 = addr(evalblock_evdata);
         ST    3,CAMLST+4      camlst(2) = addr(evalblock_evdata);
         MVC   EVALBLOCK_EVLEN,=F'44'  RESULT length=44
         MVI   0(3),C' '       evalblock_evdata(1:44) = input dsn
         MVC   1(43,3),0(3)       Clear 44 bytes
         L     9,16(1)            R9  = Addr of parm list
         L     11,0(,9)           r11 = Addr of input dsname
         L     9,4(,9)            r9  = Length of input dsname
         BCTR  9,0
         EX    9,MVCINSTR         -> EX MVC 0(0,3),0(11)
         LA    1,CAMLST        r1 = addr(camlst);
         SVC   26              Issue locate
         LTR   15,15           IF r15 = 0 THEN
         BZ    EXIT              goto exit
         MVC   EVALBLOCK_EVLEN,=F'7'              RESULT length=7
         MVC   EVALBLOCK_EVDATA(7),=CL7'UNKNOWN'  RESULT='UNKNOWN'
EXIT     LM    14,12,12(13)    Return code(0)
         SLR   15,15
         BR    14
MVCINSTR MVC   0(0,3),0(11)    Target of EX instruction
WORKAREA DS    32D
CAMLST   DC    XL4'44000000',A(0),A(0),A(WORKAREA)
         IRXEVALB
         END   REALNAME