readc.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/readc.c    92.3    06/21/99 10:37:55"

/*
 *      read characters
 */

#include <errno.h>
#include <foreign.h>
#include <liberrno.h>
#include "fio.h"

#define BLANK (long) ' '

#define ERET(err) {     \
        chars   = 0;    \
        errn    = err;  \
        goto done;      \
}

static void __READC();

/*
 *      Read characters, full record mode
 */

void
READC(
        _f_int  *unump,
        _f_int  *uda,
        _f_int  *charsp,
        _f_int  *status )
{
        __READC(FULL, unump, uda, charsp, status);

        return;
}
 
/*
 *      Read characters, partial record mode
 */
 
void
READCP(
        _f_int  *unump,
        _f_int  *uda,
        _f_int  *charsp,
        _f_int  *status )
{
        __READC(PARTIAL, unump, uda, charsp, status);

        return;
}
/*
 *      Read characters, full or partial record mode;
 *
 *      The READ/READP interface does not advance past logical endfile 
 *      records.
 */
static void
__READC(
        int     fulp,
        _f_int  *unump,
        _f_int  *uda,
        _f_int  *charsp,
        _f_int  *status)
{
        register int    ret;
        register int    errn;
        long            rstat;
        long            chars;
        unum_t          unum;
        unit            *cup;
        struct fiostate cfs;

        chars   = *charsp;
        unum    = *unump;
        errn    = 0;

        STMT_BEGIN(unum, 0, T_RSF, NULL, &cfs, cup);
/*
 *      If not connected, do an implicit open.  
 */
        if (cup == NULL) {
                int     ostat;

                cup     = _imp_open(&cfs, SEQ, FMT, unum, 1, &ostat);

                if (cup == NULL)
                        ERET(ostat);
        }

        if (!cup->ok_rd_seq_fmt) {
                errn    = _get_mismatch_error(1, T_RSF, cup, &cfs);
                ERET(errn);
        }

        cup->uwrt       = 0;

        ret     = _frch(cup, (long *) uda, chars, fulp, &rstat );

        if ( ret == IOERR ) {
                if (errno == FETAPUTE) {
                        /* This should be fixed, so that chars */
                        /* returns the amount of data read */
                        errn    = 4;
                }
                else if (errno > 5) {
                        chars   = 0;
                        errn    = errno;
                }
                else{
                        chars   = 0;

                        /* Map system errnos 1-4 to library */
                        /* errnos. Otherwise, we would lose them. */
                        switch (errno) {
                                case 1:
                                        errn    = FEKLUDG1;
                                        break;
                                case 2:
                                        errn    = FEKLUDG2;
                                        break;
                                case 3:
                                        errn    = FEKLUDG3;
                                        break;
                                case 4:
                                        errn    = FEKLUDG4;
                                        break;
                        }
                }
                goto done;
        }
          
        if (ret < chars)
                (void) _memwset(&uda[ret], BLANK, chars - ret);

        if ( rstat == EOR ) {
                cup->uend       = BEFORE_ENDFILE;
                errn            = 0;            /* EOR */
                if ( ret == 0 ) 
                        errn    = 1;    /* NULL record */
                chars   = ret;          /* number of characters read */
        }
        else if ( rstat == CNT ) { 
                cup->uend = BEFORE_ENDFILE;
                errn    = -1;           /* CHARACTERS REMAIN in record */
                chars   = ret;          /* number of characters read */
        }
        else if (rstat == EOD) {
                errn    = 3;            /* EOD */
                chars   = 0;            /* number of characters read */
        }
        else {
                cup->uend = PHYSICAL_ENDFILE;
                errn    = 2;            /* EOF */
                chars   = 0;            /* number of characters read */
        }

done:

        *charsp = chars;
        *status = errn;

        STMT_END(cup, TF_READ, NULL, &cfs);

        return;
}