length.c

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/*

  Copyright (C) 2000, 2001, Silicon Graphics, Inc.  All Rights Reserved.

  This program is free software; you can redistribute it and/or modify it
  under the terms of version 2.1 of the GNU Lesser General Public License 
  as published by the Free Software Foundation.

  This program is distributed in the hope that it would be useful, but
  WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  

  Further, this software is distributed without any warranty that it is
  free of the rightful claim of any third person regarding infringement 
  or the like.  Any license provided herein, whether implied or 
  otherwise, applies only to this software file.  Patent licenses, if
  any, provided herein do not apply to combinations of this program with 
  other software, or any other product whatsoever.  

  You should have received a copy of the GNU Lesser General Public 
  License along with this program; if not, write the Free Software 
  Foundation, Inc., 59 Temple Place - Suite 330, Boston MA 02111-1307, 
  USA.

  Contact information:  Silicon Graphics, Inc., 1600 Amphitheatre Pky,
  Mountain View, CA 94043, or:

  http://www.sgi.com

  For further information regarding this notice, see:

  http://oss.sgi.com/projects/GenInfo/NoticeExplan

*/



#pragma ident "@(#) libf/fio/length.c   92.1    06/21/99 10:37:21"
#include <foreign.h>
#include <fortran.h>
#include <liberrno.h>
#include <sys/param.h>
#include <errno.h>
#include "fio.h"

/*
 *      _LENGTH_
 *
 *              Intrinsic LENGTH function returns the amount of data 
 *              transferred by the preceding BUFFER IN or BUFFER OUT request.
 *
 *      Return Value
 *
 *              The size in words of the preceding BUFFER IN/OUT statement.
 *              Partial words are counted.
 *
 *              Returns 0 if of an end-of-file or an error occurs, or after a
 *              read or write of a zero-length record.
 *
 *              Undocumented feature:  S2 is assigned on exit the 
 *              "unused bit count".  This is the number of bits untransferred 
 *              in the last word of the previous I/O request.
 *
 *      Define duplicate entry points
 *
 *              _LENGTH_ - if user declares it INTRINSIC with CF90 
 *              LENGTH   - if user declaris it EXTERNAL or CALL's it
 *              $LENGTH  - if user declares it INTRINSIC with CF77
 *              _LENGTH  - if user declares it INTRINSIC with CF77 6.0.0.3 or
 *                         previous on the T3D (obsolete)
 */
#ifdef  _UNICOS
#pragma _CRI duplicate _LENGTH_ as LENGTH
#pragma _CRI duplicate _LENGTH_ as $LENGTH
#ifdef _CRAYMPP
#pragma _CRI duplicate _LENGTH_ as _LENGTH
#endif
#endif  /* _UNICOS */

_f_int
_LENGTH_(_f_int *unump)
{
        unum_t  unum;
        unit    *cup;
        int     ret, s2ret;
        struct fiostate cfs;

        unum    = *unump;

        STMT_BEGIN(unum, 0, T_LENGTH, NULL, &cfs, cup); /* lock the unit */
/*
 *      If not connected, do an implicit open.  Abort if the open fails.
 */
        if (cup == NULL)
                cup     = _imp_open(&cfs, SEQ, UNF, unum, 0, NULL);

        WAITIO(cup, { cup->uerr = 1; } );       /* await outstanding I/O */

        if (cup->uerr) {
                ret     = 0;
                s2ret   = 0;
        }
        else {
                ret     = (cup->ulrecl + BITS_PER_WORD - 1) / BITS_PER_WORD;
                s2ret   = (ret * BITS_PER_WORD) - cup->ulrecl;
        }

        STMT_END(cup, T_LENGTH, NULL, &cfs);    /* unlock the unit */

#ifdef  _CRAY1
        (void) _sets2(s2ret);
#endif

        return( (_f_int) ret);
}