newlib/libc/stdio/flags.c

   1 /*
   2  * Copyright (c) 1990 Regents of the University of California.
   3  * All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms are permitted
   6  * provided that the above copyright notice and this paragraph are
   7  * duplicated in all such forms and that any documentation,
   8  * and/or other materials related to such
   9  * distribution and use acknowledge that the software was developed
  10  * by the University of California, Berkeley.  The name of the
  11  * University may not be used to endorse or promote products derived
  12  * from this software without specific prior written permission.
  13  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
  14  * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
  15  * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
  16  */
  17 /* No user fns here. Pesch 15apr92 */
  18
  19 #include <_ansi.h>
  20 #include <stdio.h>
  21 #include <time.h>
  22 #include <fcntl.h>
  23 #include <errno.h>
  24 #include <sys/types.h>
  25
  26 /*
  27  * Return the (stdio) flags for a given mode.  Store the flags
  28  * to be passed to an open() syscall through *optr.
  29  * Return 0 on error.
  30  */
  31
  32 int
  33 __sflags (struct _reent *ptr,
  34        register char *mode,
  35        int *optr)
  36 {
  37   register int ret, m, o;
  38
  39   switch (mode[0])
  40     {
  41     case 'r':                   /* open for reading */
  42       ret = __SRD;
  43       m = O_RDONLY;
  44       o = 0;
  45       break;
  46
  47     case 'w':                   /* open for writing */
  48       ret = __SWR;
  49       m = O_WRONLY;
  50       o = O_CREAT | O_TRUNC;
  51       break;
  52
  53     case 'a':                   /* open for appending */
  54       ret = __SWR | __SAPP;
  55       m = O_WRONLY;
  56       o = O_CREAT | O_APPEND;
  57       break;
  58     default:                    /* illegal mode */
  59       _REENT_ERRNO(ptr) = EINVAL;
  60       return (0);
  61     }
  62   while (*++mode)
  63     {
  64       switch (*mode)
  65         {
  66         case '+':
  67           ret = (ret & ~(__SRD | __SWR)) | __SRW;
  68           m = (m & ~O_ACCMODE) | O_RDWR;
  69           break;
  70         case 'b':
  71 #ifdef O_BINARY
  72           m |= O_BINARY;
  73 #endif
  74           break;
  75 #ifdef __CYGWIN__
  76         case 't':
  77           m |= O_TEXT;
  78           break;
  79 #endif
  80 #if defined (O_CLOEXEC) && defined (_GLIBC_EXTENSION)
  81         case 'e':
  82           m |= O_CLOEXEC;
  83           break;
  84 #endif
  85         case 'x':
  86           m |= O_EXCL;
  87           break;
  88         default:
  89           break;
  90         }
  91     }
  92   *optr = m | o;
  93   return ret;
  94 }