src/system/libroot/posix/stdio/flags.c

   1 /*-
   2  * Copyright (c) 1990, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Chris Torek.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 3. All advertising materials mentioning features or use of this software
  17  *    must display the following acknowledgement:
  18  *      This product includes software developed by the University of
  19  *      California, Berkeley and its contributors.
  20  * 4. Neither the name of the University nor the names of its contributors
  21  *    may be used to endorse or promote products derived from this software
  22  *    without specific prior written permission.
  23  *
  24  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  25  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  26  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  27  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  28  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  29  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  30  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  31  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  32  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  33  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  34  * SUCH DAMAGE.
  35  */
  36
  37 #include <ktypes.h>
  38 //#include <sys/types.h>
  39 //#include <sys/file.h>
  40 #include <stdio.h>
  41 #include <errno.h>
  42 #include <fcntl.h>
  43
  44 #include <errno_private.h>
  45
  46 #include "local.h"
  47
  48 /*
  49  * Return the (stdio) flags for a given mode.  Store the flags
  50  * to be passed to an open() syscall through *optr.
  51  * Return 0 on error.
  52  */
  53 int
  54 __sflags(mode, optr)
  55         register const char *mode;
  56         int *optr;
  57 {
  58         register int ret, m, o;
  59
  60         switch (*mode++) {
  61
  62         case 'r':       /* open for reading */
  63                 ret = __SRD;
  64                 m = O_RDONLY;
  65                 o = 0;
  66                 break;
  67
  68         case 'w':       /* open for writing */
  69                 ret = __SWR;
  70                 m = O_WRONLY;
  71                 o = O_CREAT | O_TRUNC;
  72                 break;
  73
  74         case 'a':       /* open for appending */
  75                 ret = __SWR;
  76                 m = O_WRONLY;
  77                 o = O_CREAT | O_APPEND;
  78                 break;
  79
  80         default:        /* illegal mode */
  81                 __set_errno(EINVAL);
  82                 return (0);
  83         }
  84
  85         /* [rwa]\+ or [rwa]b\+ means read and write */
  86         if (*mode == '+' || (*mode == 'b' && mode[1] == '+')) {
  87                 ret = __SRW;
  88                 m = O_RDWR;
  89         }
  90         *optr = m | o;
  91         return (ret);
  92 }