cde/programs/dtksh/ksh93/src/lib/libast/sfio/sfopen.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 librararies 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: sfopen.c /main/3 1995/11/01 18:32:00 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 /*      Open a file/string for IO.
  49 **      If f is not nil, it is taken as an existing stream that should be
  50 **      closed and its structure reused for the new stream.
  51 **
  52 **      Written by Kiem-Phong Vo (06/27/90)
  53 */
  54
  55 #if __STD_C
  56 Sfio_t *sfopen(reg Sfio_t* f, const char* file, const char* mode)
  57 #else
  58 Sfio_t *sfopen(f,file,mode)
  59 reg Sfio_t      *f;             /* old stream structure */
  60 char            *file;          /* file/string to be opened */
  61 reg char        *mode;          /* mode of the stream */
  62 #endif
  63 {
  64         int     fd, oldfd, oflags, sflags;
  65
  66         if((sflags = _sftype(mode,&oflags)) == 0)
  67                 return NIL(Sfio_t*);
  68
  69         if(sflags&SF_STRING)
  70                 fd = -1;
  71         else
  72         {       /* open the file */
  73                 if(!file)
  74                         return NIL(Sfio_t*);
  75
  76 #ifndef NO_OFLAGS
  77                 while((fd = open((char*)file,oflags,0666)) < 0 && errno == EINTR)
  78                         errno = 0;
  79 #else
  80                 while((fd = open(file,oflags&03)) < 0 && errno == EINTR)
  81                         errno = 0;
  82                 if(fd >= 0)
  83                 {       if(oflags&O_TRUNC)
  84                         {       reg int tf;
  85                                 while((tf = creat(file,0666)) < 0 && errno == EINTR)
  86                                         errno = 0;
  87                                 CLOSE(tf);
  88                         }
  89                 }
  90                 else if(oflags&O_CREAT)
  91                 {       while((fd = creat(file,0666)) < 0 && errno == EINTR)
  92                                 errno = 0;
  93                         if(!(oflags&O_WRONLY))
  94                         {       /* the file now exists, reopen it for read/write */
  95                                 CLOSE(fd);
  96                                 while((fd = open(file,oflags&03)) < 0 && errno == EINTR)
  97                                         errno = 0;
  98                         }
  99                 }
 100 #endif
 101                 if(fd < 0)
 102                         return NIL(Sfio_t*);
 103         }
 104
 105         oldfd = (f && !(f->flags&SF_STRING)) ? f->file : -1;
 106
 107         if(sflags&SF_STRING)
 108                 f = sfnew(f,(char*)file,file ? (int)strlen((char*)file) : -1,fd,sflags);
 109         else if((f = sfnew(f,NIL(char*),-1,fd,sflags|SF_OPEN)) && oldfd >= 0)
 110                 (void)sfsetfd(f,oldfd);
 111
 112         return f;
 113 }
 114
 115 #if __STD_C
 116 _sftype(reg const char *mode, int *oflagsp)
 117 #else
 118 _sftype(mode, oflagsp)
 119 reg char        *mode;
 120 int             *oflagsp;
 121 #endif
 122 {
 123         reg int sflags, oflags;
 124
 125         if(!mode)
 126                 return 0;
 127
 128         /* construct the open flags */
 129         sflags = oflags = 0;
 130         while(1) switch(*mode++)
 131         {
 132         case 'w' :
 133                 sflags |= SF_WRITE;
 134                 oflags |= O_WRONLY | O_CREAT;
 135                 if(!(sflags&SF_READ))
 136                         oflags |= O_TRUNC;
 137                 continue;
 138         case 'a' :
 139                 sflags |= SF_WRITE | SF_APPEND;
 140                 oflags |= O_WRONLY | O_APPEND | O_CREAT;
 141                 continue;
 142         case 'r' :
 143                 sflags |= SF_READ;
 144                 oflags |= O_RDONLY;
 145                 continue;
 146         case 's' :
 147                 sflags |= SF_STRING;
 148                 continue;
 149         case 'b' :
 150                 oflags &= ~O_TEXT;
 151                 oflags |= O_BINARY;
 152                 continue;
 153         case 't' :
 154                 oflags &= ~O_BINARY;
 155                 oflags |= O_TEXT;
 156                 continue;
 157         case '+' :
 158                 if(sflags)
 159                         sflags |= SF_READ|SF_WRITE;
 160                 continue;
 161         default :
 162                 if((sflags&SF_RDWR) == SF_RDWR)
 163                         oflags = (oflags&~(O_RDONLY|O_WRONLY))|O_RDWR;
 164                 if(!(oflags&O_BINARY) && (sflags&SF_READ))
 165                         oflags |= O_TEXT;
 166                 if(oflagsp)
 167                         *oflagsp = oflags;
 168                 if((sflags&(SF_STRING|SF_RDWR)) == SF_STRING)
 169                         sflags |= SF_READ;
 170                 return sflags;
 171         }
 172 }