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root/usr/lib/libc/stdio/flags.c

DEFINITIONS

1. __sflags

   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. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  33 #include <sys/types.h>
  34 #include <sys/fcntl.h>
  35 #include <stdio.h>
  36 #include <errno.h>
  38 /*
  39  * Return the (stdio) flags for a given mode.  Store the flags
  40  * to be passed to an open() syscall through *optr.
  41  * Return 0 on error.
  42  */
  43 int
__sflags(char *mode, int *optr)
  45 {
  46         int ret, m, o;
  48         switch (*mode++) {
  50         case 'r':       /* open for reading */
ret = __SRD;
m = O_RDONLY;
o = 0;
  54                 break;
  56         case 'w':       /* open for writing */
ret = __SWR;
m = O_WRONLY;
o = O_CREAT | O_TRUNC;
  60                 break;
  62         case 'a':       /* open for appending */
ret = __SWR;
m = O_WRONLY;
o = O_CREAT | O_APPEND;
  66                 break;
  68         default:        /* illegal mode */
errno = EINVAL;
  70                 return (0);
  71         }
  73         /* [rwa]\+ or [rwa]b\+ means read and write */
  74         if (*mode == '+' || (*mode == 'b' && mode[1] == '+')) {
ret = __SRW;
m = O_RDWR;
  77         }
  78         *optr = m | o;
  79         return (ret);
  80 }