In the following example, the list of volumes containing generation data set A.PAY(-3) is read into virtual storage.

          LOCATE    INDGX                 READ CATALOG ENTRY
*                                         FOR DATA SET A.PAY(-3)
*                                         INTO YOUR STORAGE
*                                         AREA NAMED LOCAREA
         Check Return Codes
 
INDGX     CAMLST    NAME,APAY,,LOCAREA
APAY      DC        CL44'A.PAY(-3)'
LOCAREA   DS        0D
          DS        265C

The LOCATE macro instruction points to the CAMLST macro instruction. NAME, the first operand of CAMLST, initiates a search for a catalog entry using the name of a data set. APAY, the second operand, specifies the virtual storage location of the name of the generation index and the relative generation number of a data set in the generation data group. LOCAREA, the fourth operand, specifies a 265-byte area you have reserved to receive the catalog information.

After executing this macro instruction, the system replaces the relative generation number that you specified with the data set's absolute generation name. Control is returned to your program at the next executable instruction following the LOCATE macro instruction. If the entry has been located and read successfully, register 15 contains zeros. Otherwise, register 15 contains a return code (see Return Codes from LOCATE). See Retrieving Information by Data Set Name (LOCATE and CAMLST NAME) for a description of the contents of the output area.