/* ------------------------- REXX ---------------------------------- *
 * Name:  finddsn                                                    *
 *                                                                   *
 * Function: Find the datasets allocted to a specified ddname        *
 *                                                                   *
 * Usage:    called from a rexx or clist                             *
 *                                                                   *
 *           library = finddsn(ddname)                               *
 *                                                                   *
 *           library will contain a count of dsnames found for the   *
 *           dd followed by the dsnames                              *
 *                                                                   *
 *           For example:                                            *
 *                                                                   *
 *           xx=finddsn(ispmlib);say xx                              *
 *            2 ISP.SISPMENU SYS1.PROD.ISPMENU                       *
 *                                                                   *
 * History:                                                          *
 *           Updated 05/09/2019 improve results                      *
 *           Updated 11/13/2013 by Lionel B. Dyck                    *
 *                   - created from FINDDDN                          *
 *           Updated 10/28/2013 by Lionel B. Dyck                    *
 *                   - cleanup for COMMAND and FUNCTION              *
 *                     generalization                                *
 *           Updated 5/28/2013 by Lionel B. Dyck                     *
 *                   - add test for function or command invocation   *
 *           Created 5/24/2013 by Lionel B. Dyck                     *
 * ----------------------------------------------------------------- */

/* ----------------------------------------------------------------- *
 * Access variables to be used                                       *
 * ----------------------------------------------------------------- */
 parse source with sourcetype .
 arg dd

/* ---------------------------- *
 * Define our working variables *
 * ---------------------------- */
 hit = 0
 results = ''

/* ----------------------------------------------------------------- *
 * Trap list of current allocations                                  *
 * ----------------------------------------------------------------- */
 call outtrap 'trap.'
 Address TSO 'listalc sta'
 call outtrap 'off'

/* ----------------------------------------------------------------- *
 * Process the allocations to find our DD                            *
 *    Skip the 1st record                                            *
 * ----------------------------------------------------------------- */
 do i = 2 to trap.0
    Select
      When left(trap.i,1) <> ' '
           then do
                dsn = word(trap.i,1)
                if hit = 1 then call return_dsn
                end
      When substr(trap.i,3,1) <> ' '
           then do
                ddn = word(trap.i,1)
                if ddn <> dd
                   then if hit = 1 then signal dd_done
                   else iterate
                hit = 1
                call return_dsn
                end
      Otherwise nop
    end
    end

 return words(results) results

/* ----------------------------------------------------------------- *
 * Done so get out of here                                           *
 * ----------------------------------------------------------------- */
 dd_done:
 results = subword(results,1,words(results)-1)
 if sourcetype = 'COMMAND' then do
     say '>>'results'<<'
     return
     end
 if length(results) = 0 then return 8
 if sourcetype = 'FUNCTION' then
    return words(results) results

/* ----------------------------------------------------------------- *
 * Test dsname for member and return all dsn's                       *
 * ----------------------------------------------------------------- */
 return_dsn: Procedure Expose results dsn
   testdsn = "'"dsn"'"
   results = strip(results dsn)
   return