cde/programs/dtksh/ksh93/src/lib/libast/sfio/sfsk.c

   1 /*
   2  * CDE - Common Desktop Environment
   3  *
   4  * Copyright (c) 1993-2012, The Open Group. All rights reserved.
   5  *
   6  * These libraries and programs are free software; you can
   7  * redistribute them and/or modify them under the terms of the GNU
   8  * Lesser General Public License as published by the Free Software
   9  * Foundation; either version 2 of the License, or (at your option)
  10  * any later version.
  11  *
  12  * These libraries and programs are distributed in the hope that
  13  * they will be useful, but WITHOUT ANY WARRANTY; without even the
  14  * implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
  15  * PURPOSE. See the GNU Lesser General Public License for more
  16  * details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with these libraries and programs; if not, write
  20  * to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
  21  * Floor, Boston, MA 02110-1301 USA
  22  */
  23 /* $XConsortium: sfsk.c /main/3 1995/11/01 18:36:35 rswiston $ */
  24 /***************************************************************
  25 *                                                              *
  26 *                      AT&T - PROPRIETARY                      *
  27 *                                                              *
  28 *         THIS IS PROPRIETARY SOURCE CODE LICENSED BY          *
  29 *                          AT&T CORP.                          *
  30 *                                                              *
  31 *                Copyright (c) 1995 AT&T Corp.                 *
  32 *                     All Rights Reserved                      *
  33 *                                                              *
  34 *           This software is licensed by AT&T Corp.            *
  35 *       under the terms and conditions of the license in       *
  36 *       http://www.research.att.com/orgs/ssr/book/reuse        *
  37 *                                                              *
  38 *               This software was created by the               *
  39 *           Software Engineering Research Department           *
  40 *                    AT&T Bell Laboratories                    *
  41 *                                                              *
  42 *               For further information contact                *
  43 *                     gsf@research.att.com                     *
  44 *                                                              *
  45 ***************************************************************/
  46 #include        "sfhdr.h"
  47
  48 /*      Seek function that knows discipline
  49 **
  50 **      Written by Kiem-Phong Vo (02/12/91)
  51 */
  52 #if __STD_C
  53 long sfsk(reg Sfio_t* f, reg long addr, reg int type, reg Sfdisc_t* disc)
  54 #else
  55 long sfsk(f,addr,type,disc)
  56 reg Sfio_t      *f;
  57 reg long        addr;
  58 reg int         type;
  59 reg Sfdisc_t    *disc;
  60 #endif
  61 {
  62         reg long        p;
  63         reg int         s, local, string;
  64
  65         GETLOCAL(f,local);
  66         if(!local && !(f->mode&SF_LOCK))
  67                 return -1;
  68
  69         if(!(string = (f->flags&SF_STRING)))
  70                 SFDISC(f,disc,seekf,local);
  71
  72         for(;;)
  73         {
  74                 if(string)
  75                 {       SFSTRSIZE(f);
  76                         if(type == 0)
  77                                 s = (int)addr;
  78                         else if(type == 1)
  79                                 s = (int)(addr + f->here);
  80                         else    s = (int)(addr + f->extent);
  81                 }
  82                 else
  83                 {
  84                         if(disc && disc->seekf)
  85                                 p = (*(disc->seekf))(f,addr,type,disc);
  86                         else    p = lseek(f->file,addr,type);
  87                         if(p >= 0)
  88                                 return p;
  89                         s = -1;
  90                 }
  91
  92                 if(local)
  93                         SETLOCAL(f);
  94                 switch(_sfexcept(f,SF_SEEK,s,disc))
  95                 {
  96                 case SF_EDISC:
  97                 case SF_ECONT:
  98                         if(string)
  99                                 return 0L;
 100                         continue;
 101                 default:
 102                         return -1L;
 103                 }
 104         }
 105 }