Practice

/* rexx */
VOLSER='Z1DBMR'
CALL FIND
SAY TAPENAME SEQ
EXIT 0
/* MAIN FIND PROC */
FIND: PROCEDURE EXPOSE VOLSER TAPENAME SEQ
/* FINDING VOLSER */
/* cutting disk name */
DSNLOG=SYSDSN("'SOFT.SUPPORT("VOLSER")'")
/* CHECKING IF DISK NAME IS EXIST IN SOFT SUPPORT */
IF DSNLOG='OK' THEN
DO
  "alloc da('SOFT.SUPPORT("VOLSER")') F(INPUT) shr reuse"
  "execio * diskr INPUT (stem VOL. finis"
  "FREE F(INPUT)"
  TAPENAME=SUBSTR(VOL.3,57,6)
  /* IF TEMP FILE(LIB1) EXIST */
  /* THEN DELETE IT */
if sysdsn("'LIB1'")='OK' THEN
DO
ADDRESS TSO "DELETE 'LIB1'"
END
/* LISTING OUT ALL FILES FROM THE TAPE: */
"HSEND LIST DUMPVOLUME("TAPENAME") ODS('LIB1')"
/* FINDiNG PROCESS */
/* WAITING FOR PREVIOUS FREE F() */
ADDRESS SYSCALL 'sleep 1'
"alloc da('lib1') F(indd) shr reuse"
"execio * diskr indd (stem strings. finis"
"free f(indd)"
/* P - VARIABLE FOR INCREMENTING STEMS AND CHECKING FIND RESULT */
P=0
DO I=1 TO STRINGS.0
IF INDEX(STRINGS.I,' 'VOLSER' ') /= 0 THEN
  DO
    P=P+1
    STRS.0=P
    STRSFULL.0=P
      STRS.P=SUBSTR(STRINGS.I,25,3)
      STRSFULL.P=STRINGS.I
    END
  END
  IF P /= 0 THEN
  DO
    IF P>1 THEN
    DO
      /* SETTING UP 1ST LINE AS INITIAL YYYY/MM/DD */
      Y=SUBSTR(STRSFULL.1,50,4)
      M=SUBSTR(STRSFULL.1,55,2)
      D=SUBSTR(STRSFULL.1,58,2)
      SEQ=SUBSTR(STRSFULL.1,25,3)
      DO I=2 TO STRS.0
        IF SUBSTR(STRSFULL.I,50,4)>Y THEN
        DO
          Y=SUBSTR(STRSFULL.I,50,4)
          M=SUBSTR(STRSFULL.I,55,2)
          D=SUBSTR(STRSFULL.I,58,2)
          SEQ=SUBSTR(STRSFULL.I,25,3)
        END
        ELSE
        IF SUBSTR(STRSFULL.I,50,4)=Y THEN
        DO
          IF SUBSTR(STRSFULL.I,55,2)>M THEN
          DO
            M=SUBSTR(STRSFULL.I,55,2)
            D=SUBSTR(STRSFULL.I,58,2)
            SEQ=SUBSTR(STRSFULL.I,25,3)
          END
          ELSE
          IF SUBSTR(STRSFULL.I,55,2)=M THEN
          DO
            IF SUBSTR(STRSFULL.I,58,2)>D THEN
            DO
              D=SUBSTR(STRSFULL.I,58,2)
              SEQ=SUBSTR(STRSFULL.I,25,3)
            END
          END
        END
       END
       SEQ=SEQ*1
       /* SAY 'LAST DATE:'||Y||'/'||M||'/'||D||' */
       RETURN 1
       /* MUL 1 FOR REFORMAT 003 ==> 3 */
     END
     ELSE
     DO
     SEQ=SUBSTR(STRSFULL.1,25,3)*1
     RETURN 1
     END
   END
   ELSE
   EXIT 0
 END
 ELSE
 DO
 SAY VOSLER 'NOT FOUND ON SOFT.SUPPORT'
 RETURN 0
 END
 EXIT 0