*
* $Id: eprwnd.F,v 1.2 1996/04/11 12:34:10 mclareni Exp $
*
* $Log: eprwnd.F,v $
* Revision 1.2  1996/04/11 12:34:10  mclareni
* F. Ranjard's protection for rewinding with a wrong file descriptor
*
* Revision 1.1.1.1  1996/03/08 15:21:44  mclareni
* Epio
*
*
#include "epio/pilot.h"
      SUBROUTINE EPRWND(LUNIT,IBUF,IERR)
C.
C.  REWINDING AN OUTPUT UNIT CLOSES THE UNIT AND WRITES AN END  OF  FILE
C.   MARK  (ROUTINE  EPEOF).  AFTER A REWIND OPERATION (AND ONLY IN THAT
C.  CASE) THE USER MAY SWITCH FROM READING TO WRITING OR VICE VERSA.
C.
C. THE PHYS. HEADER IS RESET TO THE STANDARD HEADER AFTER A REWIND.
C. THE BLOCK AND RECORD COUNTS ARE RESET TO ZERO.
C.
C. INPUT:
C.
C. LUNIT    LOGICAL UNIT
C.
C. IBUF     USER PROVIDED UNIT BUFFER. MUST NOT BE TOUCHED BY USER.
C.
C. OUTPUT:
C.
C. IERR     ERROR FLAG. SEE SEPARATE LIST.
#if defined(CERNLIB_APOLLO)
%INCLUDE '/sys/ins/base.ins.ftn'
%INCLUDE '/sys/ins/error.ins.ftn'
%INCLUDE '/sys/ins/streams.ins.ftn'
      INTEGER*2 STREAM_$ID,ERROR_$RETURNED
      INTEGER STATUS_$RETURNED,ATT_$REC_4(16)
      EQUIVALENCE (ATT_$REC_4,STREAM_$ID)
#endif
#include "epio/epiocom.inc"
      DIMENSION IBUF(2)
C--- CHECK WHETHER SAME USER UNIT AS LAST TIME
      IF(LASTUT.EQ.LUNIT)  GOTO 1551
C--- NEW UNIT - GET REF
      CALL EPUNIT(LUNIT,IERR)
      IF(IERR.EQ.0)  GOTO 1552
      GOTO 77777
 1551 IERR=0
      IF(LREF.NE.0)  GOTO 1552
      IERR=13
      CALL EPERRH(LUNIT,IERR)
      GOTO 77777
 1552 CONTINUE
C--- CLOSE IF OUTPUT UNIT
      IF(LIST(ISTART+16).NE.1)  GOTO 10
        CALL EPCLOS(LUNIT,IBUF,IERR)
        IF(IERR.NE.0) GOTO 77777
        IF(LIST(ISTART+33).NE.2)CALL EPEOF(LUNIT,IERR)
   10 CONTINUE
      IF(IERR.NE.0)  GOTO 77777
#if defined(CERNLIB_IBM)||defined(CERNLIB_NORD)
      CALL IORWND(LUNIT,IRETCD)
      IF(IRETCD.EQ.0)  GOTO 11
      IERR=11
      CALL EPERRH(LUNIT,IERR)
      GOTO 77777
   11 CONTINUE
#endif
#if defined(CERNLIB_CDC)||defined(CERNLIB_CRAY)||defined(CERNLIB_STF77)||defined(CERNLIB_STF77VX)
      IF(LIST(ISTART+33).EQ.0)REWIND LUNIT
      IF(LIST(ISTART+33).EQ.2 .AND. LIST(ISTART+25).NE.0)
     1  call cfrew(LIST(ISTART+25),0)
#endif
#if defined(CERNLIB_VAX)
      IF(LIST(ISTART+25).NE.0)THEN
C
C     REWIND QIO MAGTAPE HERE
C
      CALL EPMTREW(IERR)
      IF(IERR.NE.1)THEN
      WRITE(NOUTUT,1001) IERR
1001  FORMAT(/' +++ EP I/O PACKAGE VAX MAGTAPE ERROR ',Z10,' HEX ')
      IERR = 12
      CALL EPERRH(LIST(ISTART+10),IERR)
      ELSE
        IERR = 0
      ENDIF
C
      ELSE
      REWIND LUNIT
      ENDIF
#endif
#if defined(CERNLIB_APOLLO)
C
C       SEE WETHER THE UNIT HAS BEEN OPEN AT ALL,
C            OTHERWISE DO NOTHING
C
      IF(LIST(ISTART+25).NE.0) THEN
        STREAM_$ID=INT2(LIST(ISTART+25))
C
C                SEE WHETHER THIS IS A TAPE UNIT
C
        CALL STREAM_$INQUIRE (
     1    STREAM_$IRM_OTYPE,
     2     STREAM_$USE_STRID,
     3      STREAM_$ID,
     4       ERROR_$MASK,
     5        STATUS_$RETURNED)
        IF (STATUS_$RETURNED .NE. STATUS_$OK)
     1  CALL ERROR_$PRINT(STATUS_$RETURNED)
        IF(ATT_$REC_4(14).NE.16#314) THEN
*
*                 THIS IS A DISK FILE, JUST REWIND
*
          CALL STREAM_$SEEK(
     1           STREAM_$ID,
     2            STREAM_$REC,
     3             STREAM_$ABSOLUTE,
     4              1,
     5               STATUS_$RETURNED)
          IF(STATUS_$RETURNED.NE.STATUS_$OK) THEN
            SUBS_$RETURNED=ERROR_$SUBSYS(STATUS_$RETURNED)
            IF(LSHFT(ERROR_$SUBSYS(STATUS_$RETURNED),8)
     +      .NE.STREAM_$SUBS) WRITE(NOUTUT,1000)
1000        FORMAT(' +++ EPIO/DOMAIN: Not a stream I/O error ???')
            CALL ERROR_$PRINT(STATUS_$RETURNED)
          END IF
        ELSE
*
*                 THIS IS A MAG TAPE, AND WE WANT TO CLOSE THE STREAM
*
          CALL STREAM_$CLOSE(STREAM_$ID,STATUS_$RETURNED)
          LIST(ISTART+25)=0
          IF(STATUS_$RETURNED.NE.STATUS_$OK) THEN
            SUBS_$RETURNED=ERROR_$SUBSYS(STATUS_$RETURNED)
            IF(LSHFT(ERROR_$SUBSYS(STATUS_$RETURNED),8)
     +      .NE.STREAM_$SUBS) WRITE(NOUTUT,1000)
            CALL ERROR_$PRINT(STATUS_$RETURNED)
          END IF
        END IF
      END IF
#endif
#if defined(CERNLIB_UNIVAC)
      LUNFD=LIST(ISTART+24)
      IOAD=LIST(ISTART+25)
      IF(IOAD.GE.0) LIST(ISTART+25)=0
      IF(IOAD.LT.0) CALL TIOREW(LUNFD,ISTAT)
#endif
C--- RESET STATUS WORDS AS NECESSARY
      LIST(ISTART+11)=0
      LIST(ISTART+12)=0
C
C     THE CHANNEL NUMBER AND RAB ADDRESS FOR THE VAX MUST BE REMEMBERED
C     THEREFORE WE DONT ZERO ALL THE WAY TO NWUNIT
C     THE SAME HOLDS FOR UNIVAC, AND ALSO FOR THE APOLLO STREAM_$ID
      CALL UZERO(LIST,ISTART+14,ISTART+23)
77777 RETURN
      END