rdwr.c

来自「开放源码的编译器open watcom 1.6.0版的源代码」· C语言 代码 · 共 206 行

/****************************************************************************
*
*                            Open Watcom Project
*
*    Portions Copyright (c) 1983-2002 Sybase, Inc. All Rights Reserved.
*
*  ========================================================================
*
*    This file contains Original Code and/or Modifications of Original
*    Code as defined in and that are subject to the Sybase Open Watcom
*    Public License version 1.0 (the 'License'). You may not use this file
*    except in compliance with the License. BY USING THIS FILE YOU AGREE TO
*    ALL TERMS AND CONDITIONS OF THE LICENSE. A copy of the License is
*    provided with the Original Code and Modifications, and is also
*    available at www.sybase.com/developer/opensource.
*
*    The Original Code and all software distributed under the License are
*    distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
*    EXPRESS OR IMPLIED, AND SYBASE AND ALL CONTRIBUTORS HEREBY DISCLAIM
*    ALL SUCH WARRANTIES, INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF
*    MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR
*    NON-INFRINGEMENT. Please see the License for the specific language
*    governing rights and limitations under the License.
*
*  ========================================================================
*
* Description:  WHEN YOU FIGURE OUT WHAT THIS FILE DOES, PLEASE
*               DESCRIBE IT HERE!
*
****************************************************************************/


//
// RDWR         : READ/WRITE common
//

#include "ftnstd.h"
#include "rundat.h"
#include "errcod.h"

#include <string.h>

extern  void                    IOErr(int,...);
extern  void                    F_Connect(void);
extern  void                    ConnectFile(void);
extern  void                    ChkUnitId(void);
extern  void                    FindFtnFile(void);
extern  void                    ChkIOOperation(ftnfile *);
extern  void                    SysEOF(void);
extern  void                    SeekFile(ftnfile *);
extern  void                    ChkIOErr(ftnfile *);
extern  void                    OpenAction(ftnfile *);
extern  bool                    IsCarriage(void);
extern  char                    *RChkAlloc(int);

extern  char                    NormalCtrlSeq[];


void    _AllocBuffer( ftnfile *fcb ) {
//====================================

    if( fcb->buffer == NULL ) {
        if( IsCarriage() ) {
            fcb->bufflen += strlen( NormalCtrlSeq );
        }
        fcb->buffer = RChkAlloc( fcb->bufflen + 1 );
    }
}


void    IOPrologue( void ) {
//====================

    ftnfile     *fcb;
    byte        form;
    byte        accm;

    IOCB->typ = PT_NOT_STARTED;
    if( IOCB->flags & BAD_REC ) {
        IOErr( IO_IREC );
    }
    if( IOCB->set_flags & SET_INTERNAL ) {
        F_Connect();
    } else {
        ChkUnitId();
        FindFtnFile();
        if( IOCB->fileinfo == NULL ) {
            IOCB->set_flags &= ~SET_FILENAME;
            ConnectFile();
        }
    }
    fcb = IOCB->fileinfo;
    if( fcb->action == ACT_DEFAULT ) {
        fcb->action = ACTION_RW;
    }
    ChkIOOperation( fcb );
    if( fcb->cctrl == CC_DEFAULT ) {
        fcb->cctrl = CC_NO;
    }
    accm = fcb->accmode;
    if( accm == ACCM_DEFAULT ) {
        if( IOCB->set_flags & SET_RECORDNUM ) {
            accm = ACCM_DIRECT;
        } else {
            accm = ACCM_SEQUENTIAL;
        }
        fcb->accmode = accm;
    } else {
        if( ( accm == ACCM_DIRECT ) &&
                                ( IOCB->set_flags & SET_RECORDNUM ) == 0 ) {
            IOErr( IO_REC1_ACCM );
        } else if( ( ( accm == ACCM_SEQUENTIAL ) || ( accm == ACCM_APPEND ) ) &&
                   ( IOCB->set_flags & SET_RECORDNUM ) ) {
            IOErr( IO_REC2_ACCM );
        }
    }
    if( accm == ACCM_DIRECT ) {
        fcb->recnum = IOCB->recordnum; // set up recordnumber
    }
    form = fcb->formatted;
    if( form == 0 ) {                    // set up format if it was
        if( !(IOCB->flags & IOF_NOFMT) ) {     // not previously set
            form = FORMATTED_IO;
        } else {
            form = UNFORMATTED_IO;
        }
        fcb->formatted = form;
    } else {
        if( (form == FORMATTED_IO) && (IOCB->flags & IOF_NOFMT) ) {
            IOErr( IO_AF1 );
        } else if( (form == UNFORMATTED_IO) && !(IOCB->flags & IOF_NOFMT) ) {
            IOErr( IO_AF2 );
        }
    }
    if( fcb->internal != NULL ) {
        fcb->bufflen = fcb->internal->len;
        fcb->buffer = RChkAlloc( fcb->bufflen );
    } else {
        if( ( accm <= ACCM_SEQUENTIAL ) &&
            ( fcb->eofrecnum != 0 ) &&
            ( fcb->recnum >= fcb->eofrecnum ) &&
            // Consider: READ( 1, *, END=10 )
            //           ...
            //     10    WRITE( 1, * ) 'write after EOF'
            // if an EOF condition was encounterd, we don't want IO_PAST_EOF
            // on the write
            !( IOCB->flags & IOF_OUTPT ) ) {
            if( fcb->recnum != fcb->eofrecnum ) {
                IOErr( IO_PAST_EOF );
            } else {
                fcb->recnum++;
                SysEOF();
            }
        }
        _AllocBuffer( fcb );
        if( fcb->fileptr == NULL ) {
            DoOpen();
        }
        if( fcb->accmode == ACCM_DIRECT ) {
            SeekFile( fcb );
            ChkIOErr( fcb );
        }
        fcb->col = 0;
    }
    if( ( IOCB->flags & IOF_OUTPT ) && ( fcb->col == 0 ) ) {
        memset( fcb->buffer, ' ', fcb->bufflen );
    }
}


void    DoOpen( void ) {
//================

// Do the actual open of a file.

    ftnfile     *fcb;
    byte        action;

    fcb = IOCB->fileinfo;
    action = fcb->action;
    OpenAction( fcb );
    fcb->flags &= ~FTN_FSEXIST;
    if( fcb->fileptr != NULL ) {
        fcb->flags |= FTN_FSEXIST;
    }
    ChkIOErr( fcb );
}


void    UpdateRecNum( ftnfile *fcb ) {
//====================================

    if( _NoRecordOrganization( fcb ) ) return;
    if( _LogicalRecordOrganization( fcb ) ) {
        if( !(fcb->flags & FTN_LOGICAL_RECORD) ) {
            // increment record count if this is first
            // physical record of logical record
            ++fcb->recnum;
        }
        // next record will be part of a logical record
        fcb->flags |= FTN_LOGICAL_RECORD;
    } else {
        ++fcb->recnum;
    }
}